| Abciximab | Monoclonal antibody that inhibits the binding of platelet glycoprotein IIb/IIIa (GPIIb/IIIa) to fibrinogen. Used to prevent clotting after coronary angioplasty and in acute coronary syndrome. Eptifibatide and tirofiban are also GPIIb/IIIa inhibitors. (34) |
| Acetaminophen | Antipyretic analgesic: very weak cyclooxygenase inhibitor; not anti-inflammatory. Less GI distress than aspirin but dangerous in overdose. Tox: hepatic necrosis. Antidote: acetylcysteine. (36) |
| Acetazolamide | Carbonic anhydrase-inhibiting diuretic acting in the proximal convoluted tubule: produces a NaHCO3 diuresis, results in bicarbonate depletion and metabolic acidosis. Has self-limited diuretic but persistent bicarbonate-depleting action. Used in glaucoma and mountain sickness. Tox: paresthesias, hepatic encephalopathy. Dorzolamide and brinzolamide are topical analogs for glaucoma. (15) |
| Acetylcholine | Cholinomimetic prototype: transmitter in CNS, ENS, all ANS ganglia, parasympathetic postganglionic synapses, sympathetic postganglionic fibers to sweat glands, and skeletal muscle end plate synapses. (6, 7) |
| Acyclovir | Antiviral: inhibits DNA synthesis in herpes simplex virus (HSV) and varicella-zoster virus (VZV). Requires activation by viral thymidine kinase (TK− strains are resistant). Tox: behavioral effects and nephrotoxicity (crystalluria) but minimal myelosuppression. Famciclovir, penciclovir, and valacyclovir are similar but with longer half-lives. (49) |
| Adenosine | Antiarrhythmic: miscellaneous group; parenteral only. Hyperpolarizes AV nodal tissue, blocks conduction for 10–15 s. Used for nodal reentry arrhythmias. Tox: hypotension, flushing, chest pain. (14) |
| Albuterol | Prototypic rapid-acting β2 agonist; important use in acute asthma. Tox: tachycardia, arrhythmias, tremor. Other drugs with similar action: metaproterenol, terbutaline. Slow-acting analogs: formoterol, salmeterol; used for prophylaxis. (9, 20) |
| Alendronate | Bisphosphonate: chronic treatment with low doses increases bone mineral density and reduces fractures. Higher doses lower serum calcium. Used in osteoporosis and for the hypercalcemia in Paget’s disease and malignancies. Tox: esophageal irritation at low oral doses. Renal dysfunction and osteonecrosis of the jaw in high doses. Other bisphosphonates include etidronate, pamidronate, risedronate, etc. (42) |
| Allopurinol | Irreversible inhibitor of xanthine oxidase; reduces production of uric acid. Used in gout and adjunctively in cancer chemotherapy. Inhibits metabolism of purine analogs (eg, mercaptopurine, azathioprine). Febuxostat is similar. (36) |
| Alteplase (t-PA) | Thrombolytic: human recombinant tissue plasminogen activator. Used to recanalize occluded blood vessels in acute MI, severe pulmonary embolism, stroke. Reteplase and tenecteplase are similar. Streptokinase is a bacterial protein with thrombolytic properties. Tox: bleeding. (34) |
| Amiloride | K+-sparing diuretic: blocks epithelial Na+ channels in cortical collecting tubules. Tox: hyperkalemia. (15) |
| Amiodarone | Group 3 (and other groups) antiarrhythmic: broad spectrum; blocks sodium, potassium, calcium channels, β receptors. High efficacy and very long half-life (weeks to months). Tox: deposits in tissues; skin coloration; hypo- or hyperthyroidism; pulmonary fibrosis; optic neuritis. (14) |
| Amphetamine | Indirect-acting sympathomimetic: displaces stored catecholamines in nerve endings. Marked CNS stimulant actions; high abuse liability. Used in ADHD, for short-term weight loss, and for narcolepsy. Tox: psychosis, HTN, MI, seizures. Other indirect-acting sympathomimetics that displace catecholamines: ephedrine, pseudoephedrine, methylphenidate, tyramine. (9, 32) |
| Amphotericin B | Antifungal: polyene commonly a drug of choice for systemic mycoses; binds to ergosterol to disrupt fungal cell membrane permeability. Tox: chills and fever, hypotension, nephrotoxicity (dose limiting; less with liposomal forms). (48) |
| Ampicillin | Penicillin: wider spectrum than penicillin G, susceptible to penicillinases unless used with sulbactam. Activity similar to that of penicillin G, plus E coli, H influenzae, P mirabilis, Shigella. Synergy with aminoglycosides versus Enterococcus and Listeria. Tox: penicillin allergy; more adverse effects on GI tract than other penicillins; maculopapular skin rash. Amoxicillin has greater oral bioavailability and less GI effects; also used with clavulanate, a penicillinase inhibitor. (43) |
| Anastrozole | Aromatase inhibitor: prototype inhibitor of the enzyme that converts testosterone to estradiol. Used in estrogen-dependent breast cancer. Letrozole is similar; exemestane is an irreversible aromatase inhibitor. (40, 54) |
| Aspirin | NSAID prototype: inhibits cyclooxygenase (COX)-1 and -2 irreversibly. Antiplatelet agent as well as antipyretic, analgesic and anti-inflammatory drug. Tox: GI ulcers, nephrotoxicity, rash, hypersensitivity leading to bronchoconstriction, salicylism. Other NSAIDs: ibuprofen, indomethacin, ketorolac, and naproxen. (34, 36) |
| Atenolol | Beta1-selective blocker: low lipid solubility, less CNS effect; used for HTN, angina. (Mnemonic: Generic names of β1-selective blockers start with A through M except for carteolol, carvedilol, and labetalol.) Tox: asthma, bradycardia, AV block, heart failure. (10) |
| Atropine | Muscarinic cholinoceptor blocker prototype: lipid-soluble, CNS effects; antidote for cholinesterase poisoning. Tox: “red as a beet, dry as a bone, blind as a bat, mad as a hatter,” urinary retention, mydriasis. Cyclopentolate, tropicamide: antimuscarinics for ophthalmology; cause cycloplegia and mydriasis. Glycopyrrolate: antimuscarinic with decreased CNS effects. (8, 58) |
| Azithromycin | Macrolide antibiotic: similar to erythromycin but greater activity against H influenzae, chlamydiae, and streptococci; long half-life with renal elimination. Tox: GI distress but no inhibition of drug metabolism. Clarithromycin is similar but has a shorter half-life, and inhibits drug metabolism. (44) |
| Baclofen | GABA analog, orally active: spasmolytic; activates GABAB receptors in the spinal cord. (27) |
| Benztropine | Muscarinic cholinoceptor blocker: centrally acting antimuscarinic prototype for parkinsonism. Tox: excess antimuscarinic effects. (8, 28) |
| Botulinum | Toxins produced by Clostridium botulinum: enzymes that cleave proteins (synaptobrevin, others) and block transmitter release from acetylcholine vesicles. Injected to treat muscle spasm, smooth wrinkles, and reduce excessive sweating. Tox: paralysis. (6, 27) |
| Bromocriptine | Ergot derivative: prototype dopamine agonist in CNS; inhibits prolactin release. Used in hyperprolactinemia and a rarely used alternative drug in parkinsonism. Tox: Various CNS disturbances, dyskinesias, hypotension. (16, 28, 37) |
| Bupivacaine | Long-acting amide local anesthetic prototype. Tox: greater cardiovascular toxicity than most local anesthetics. (26) |
| Buprenorphine | Opioid: long-acting partial agonist of μ receptors. Analgesic (not equivalent to morphine) and effective for detoxification and maintenance in opioid dependence. Other mixed agonist-antagonists: nalbuphine activates κ and weakly blocks μ receptors; pentazocine, κ agonist and weak μ antagonist or partial agonist. (31) |
| Bupropion | Antidepressant and used in smoking cessation: mechanism uncertain, but no direct actions on CNS amines. Tox: agitation, anxiety, aggravation of psychosis and, at high doses, seizures. (30) |
| Calcitonin | Peptide hormone secreted by thyroid gland. Decreases serum calcium and phosphate by decreasing bone resorption. Delivered as a nasal spray and subcutaneous injection. Side effects: rhinitis with nasal spray. (42) |
| Captopril | ACE inhibitor prototype: used in HTN, diabetic nephropathy, and HF. Tox: hyperkalemia, fetal renal damage, cough (“sore throat”). Other “prils” include benazepril, enalapril, lisinopril, quinapril. (11, 13, 17) |
| Carbamazepine | Antiseizure drug: used for tonic-clonic and partial seizures; blocks Na+ channels in neuronal membranes. Drug of choice for trigeminal neuralgia; backup drug in bipolar disorder. Tox: CNS depression, myelotoxic, induces liver drug-metabolizing enzymes, teratogenicity. (24, 29) |
| Carvedilol | Adrenoceptor blocker: racemic mixture, one isomer is a nonselective β blocker and the other is an α1 blocker. Used in HTN, prolongs survival in HF. Tox: cardiovascular depression, asthma. Labetalol is similar. (10, 11, 13) |
| Caspofungin | Antifungal: echinocandin prototype, inhibitor of β (1-3)-glucan synthesis, a cell wall component. Used IV for disseminated Candida and Aspergillus infections. Tox: GI effects, flushing. Increases cyclosporine levels (avoid combination). (48) |
| Cefazolin | First-generation cephalosporin prototype: bactericidal beta-lactam inhibitor of cell wall synthesis. Active against gram-positive cocci, E coli, K pneumoniae, but does not enter the CNS. Tox: potential allergy; partial cross-reactivity with penicillins. (43) |
| Ceftriaxone | Third-generation cephalosporin: active against many bacteria, including pneumococci, gonococci (a drug of choice), and gram-negative rods. Enters the CNS and is used in bacterial meningitis. Cefotaxime and ceftazidime are other third-generation cephalosporins. (43) |
| Celecoxib | Selective COX-2 inhibitor. Less GI toxicity than nonselective NSAIDs. Tox: nephrotoxicity, increased risk of coronary thrombosis and stroke. (36) |
| Chloramphenicol | Antibiotic: broad-spectrum agent; inhibits protein synthesis (50S); uses restricted to backup drug for bacterial meningitis, infections due to anaerobes, Salmonella. Tox: reversible myelosuppression, aplastic anemia, gray baby syndrome. (44) |
| Chloroquine | Antimalarial: blood schizonticide used for treatment and prophylaxis in areas in which P falciparum is susceptible. Binds to heme, causing dysfunctional cell membranes; resistance resulting from efflux via P-glycoprotein pump. Tox: GI distress and skin rash at low doses; peripheral neuropathy, skin lesions, auditory and visual impairment, quinidine-like cardiotoxicity at high doses. (52) |
| Chlorpheniramine | Antihistamine first-generation H1 blocker prototype. Tox: less sedation and ANS-blocking action than diphenhydramine. (16) |
| Chlorpromazine | Phenothiazine antipsychotic drug prototype: blocks most dopamine receptors in CNS. Tox: atropine-like, EPS dysfunction, hyperprolactinemia, postural hypotension, sedation, seizures (in overdose), additive effects with other CNS depressants. Other phenothiazines: fluphenazine, trifluoperazine (antipsychotics), prochlorperazine (antiemetic), promethazine (preoperative sedation). (29) |
| Cholestyramine | Antihyperlipidemic: bile acid-binding resin prototype that sequesters bile acids in gut and diverts more cholesterol from the liver to bile acids instead of circulating lipoproteins. Used for hypercholesterolemia. Tox: constipation, bloating; interferes with absorption of some drugs. Colestipol and colesevelam are similar. (35) |
| Cimetidine | H2 blocker prototype: used in acid-peptic disease. Tox: inhibits hepatic drug metabolism; has antiandrogen effects. Less toxic analogs: ranitidine, famotidine, nizatidine. (16, 59) |
| Cinacalcet | Treatment for hyperparathyroidism. MOA: Activates the calcium-sensing receptor. Orally administered. Tox: nausea, hypocalcemia, adynamic bone. (42) |
| Ciprofloxacin | Second-generation fluoroquinolone antibiotic: bactericidal inhibitor of topoisomerases; active against E coli, H influenzae, Campylobacter, Enterobacter, Pseudomonas, Shigella. Tox: CNS dysfunction, GI distress, superinfection, collagen dysfunction (caution in children and pregnant women). Interactions: inhibits metabolism of caffeine, theophylline, warfarin. See also levofloxacin. (46) |
| Cisplatin | Antineoplastic: platinum-containing alkylating anticancer drug. Used for solid tumors (eg, testes, lung). Tox: Neurotoxic and nephrotoxic. Carboplatin and oxaliplatin are similar. (54) |
| Clindamycin | Lincosamide antibiotic: bacteriostatic inhibitor of protein synthesis (50S); active against gram-positive cocci, B fragilis. Tox: GI distress, C difficile colitis. (44) |
| Clomiphene | Selective estrogen receptor modulator (SERM): synthetic, used in infertility to induce ovulation by blocking pituitary estrogen receptors. May result in multiple births. (40) |
| Clonidine | Alpha2 agonist: acts centrally to reduce SANS outflow, lowers BP. Used in HTN and in drug dependency states. Tox: mild sedation in normal doses, rebound HTN if stopped suddenly. See also methyldopa. (9, 11, 32) |
| Clopidogrel | Antiplatelet agent: Prodrug, active metabolite irreversibly inhibits platelet ADP receptors and platelet aggregation. Used in transient ischemic attacks and to prevent strokes and restenosis after placement of coronary stents. Tox: bleeding, neutropenia. Prasugrel, ticagrelor, and ticlopidine are similar. Ticagrelor is not a prodrug and ticlopidine has higher risk of neutropenia and thrombotic thrombocytopenic purpura (TTP). (34) |
| Cocaine | Indirect-acting sympathomimetic that blocks amine reuptake into nerve endings: local anesthetic (ester type). Marked CNS stimulation, euphoria; high abuse and dependence liability. Tox: psychosis, HTN, cardiac arrhythmias, seizures. (9, 26, 32) |
| Colchicine | Microtubule assembly inhibitor: reduces macrophage mobility and phagocytosis; used in chronic gout. Tox: GI (often severe), hepatic, renal damage. (36) |
| Cyclophosphamide | Antineoplastic, immunosuppressive: cell cycle-nonspecific alkylating agent. Tox: alopecia, GI distress, hemorrhagic cystitis (use mesna), myelosuppression. (54, 55) |
| Cyclosporine | Immunosuppressant: immunophilin ligand; inhibits T-cell synthesis of cytokines. Tox: nephrotoxicity, hypertension, peripheral neuropathy, seizures. Tacrolimus is similar. Sirolimus binds to same immunophilin as tacrolimus (FKBP12), but this complex inhibits mammalian target of rapamycin (mTOR) kinase and T-cell response to IL-2. (36, 55) |
| Cytokines, recombinant | DNA technology products: aldesleukin (IL-2, used in renal cancer); erythropoietin (epoetin alfa, used in anemias); filgrastim (G-CSF, used in neutropenia); interferon-α (used in hepatitis B and C and in cancer); interferon-β (used in multiple sclerosis); interferon-γ (used in chronic granulomatous disease); oprelvekin (IL-11, used in thrombocytopenia); and sargramostim (GM-CSF, used in neutropenia). (33, 36, 49, 54, 55) |
| Dabigatran | Oral direct thrombin inhibitor: fixed dosing; no monitoring required, but can be measured with aPTT. Argatroban is a small molecule thrombin inhibitor used parenterally for PCI. Other direct thrombin inhibitors are lepirudin, a recombinant form of a medicinal leech protein, and bivalirudin—both used parenterally. Thrombin inhibitors are used in heparin-induced thrombocytopenia (HIT). Tox: bleeding; monitor with aPTT. (34) |
| Dantrolene | Muscle relaxant: blocks Ca2+ release from sarcoplasmic reticulum of skeletal muscle. Used in muscle spasm (cerebral palsy, multiple sclerosis, cord injury) and in emergency treatment of malignant hyperthermia. (25, 27, 29) |
| Denosumab | RANK ligand (RANKL) inhibitor: used for osteoporosis. Mechanism of action: binds to RANKL and prevents it from stimulating osteoclast differentiation and function. Subcutaneous injection every 6 mo. Side effects: increased risk of infection. (42) |
| Desmopressin | Vasopressin (ADH) analog, more selective for V2 receptors: used for pituitary diabetes insipidus and mild hemophilia A or von Willebrand disease. Vasopressin (ADH), an agonist for V1 and V2 receptors, is used in pituitary diabetes insipidus and bleeding esophageal varices. Conivaptan, an antagonist at V1a and V2 receptors and tolvaptan, an antagonist at V2 receptors, are used for hyponatremia. (15, 34, 37) |
| Diazepam | Benzodiazepine (BZ) prototype: binds to BZ receptors of the GABAA receptor-chloride ion channel complex; facilitates the inhibitory actions of GABA by increasing the frequency of channel opening (compare phenobarbital). Uses: anxiety states, ethanol detoxification, muscle spasticity, status epilepticus. Other benzodiazepines include alprazolam, lorazepam, midazolam, triazolam. Tox: dependence, additive effects with other CNS depressants. (22, 24, 27, 32) |
| Digoxin | Cardiac glycoside prototype: positive inotropic drug for HF, half-life 40 h; inhibits Na+/K+-ATPase. Tox: calcium overload arrhythmias, GI upset. (13, 14) |
| Diphenhydramine | Antihistamine (first-generation) H1 blocker: used in hay fever, motion sickness, dystonias. Tox: antimuscarinic, α adrenoceptor blocker, strong sedative. Doxylamine is similar. (16, 59) |
| Dopamine | Neurotransmitter and agonist drug at dopamine receptors: used in shock to increase renal blood flow (low dose) and cardiac output (moderate dose). (6, 9, 13, 21, 28, 29, 37) |
| Doxorubicin | Antineoplastic: anthracycline drug (cell cycle-nonspecific); intercalates between base pairs to disrupt DNA functions, inhibits topoisomerases, and forms cytotoxic free radicals. Tox: cardiomyopathy (dexrazoxane is antidote), myelosuppression. Daunorubicin is similar. (54) |
| Doxycycline | Tetracycline antibiotic: protein synthesis inhibitor (30S), more effective than other tetracyclines against chlamydia and in Lyme disease; malaria prophylaxis. Unlike other tetracyclines, it is eliminated mainly in the feces and has longer half-life. Tox: see tetracycline. (44, 52) |
| Edrophonium | Cholinesterase inhibitor: very short duration of action (15 min). Used in diagnosis of myasthenia gravis and to distinguish myasthenic crisis from cholinergic crisis. (7) |
| Efavirenz | Nonnucleoside reverse transcriptase inhibitor (NNRTI): used in combination regimens for HIV. Tox: skin rash, CNS effects, avoid in pregnancy. Other NNRTIs: delavirdine, nevirapine. (49) |
| Enfuvirtide | Antiviral: HIV fusion inhibitor used in combination regimens. Tox: injection site reactions and rare hypersensitivity. (49) |
| Enoxaparin | LMW heparin: used parenterally for anticoagulation. Primary effect is on factor Xa, less on thrombin. The aPTT test is unreliable. Other LMW heparins include dalteparin, tinzaparin. Tox: bleeding. (34) |
| Entacapone | COMT inhibitor: enhances levodopa access to CNS neurons; adjunctive use in Parkinson’s disease. Tox: exacerbates levodopa effects. Tolcapone is similar in action and use but can be hepatotoxic. (28) |
| Ephedrine | Indirectly acting sympathomimetic: like amphetamine but less CNS stimulation, more smooth muscle effects. In botanicals (eg, ma huang) and products for weight loss that are banned in the United States. Tox: hypertension, stroke, MI. (9, 60) |
| Epinephrine | Adrenoceptor agonist prototype: product of adrenal medulla, some CNS neurons. Affinity for all α and all β receptors. Drug of choice in anaphylaxis; used as hemostatic and as adjunct with local anesthetics; cardiac stimulant; traditional use in asthma. Tox: tachycardia, hypertension, MI, pulmonary edema, hemorrhage. (6, 9) |
| Ergot alkaloids | Ergonovine, ergotamine: cause prolonged vasoconstriction and uterine contraction. Used in migraine and obstetrics. Tox: vasospasm (including coronaries). (16) |
| Erythromycin | Macrolide antibiotic: bacteriostatic inhibitor of protein synthesis (50S); activity includes gram-positive cocci and bacilli, M pneumoniae, Legionella pneumophila, C trachomatis. Tox: cholestatic jaundice (avoid estolate in pregnancy), inhibits liver drug-metabolizing enzymes, interactions with cisapride, theophylline, warfarin. Other macrolide antibiotics include azithromycin (no effect on P450 drug metabolism) and clarithromycin. (44) |
| Erythropoietin | Hematopoietic growth factor: stimulates RBC production and release from bone marrow. Used in anemia associated with renal failure and anemias secondary to cancer chemotherapy. Darbepoetin alfa has a longer half-life. (33) |
| Etanercept | DMARD: recombinant protein that binds TNF-α. Infliximab and adalimumab have a similar mechanism of action. Effective in rheumatoid arthritis and other chronic inflammatory diseases. Tox: injection site reactions include erythema, itching, and swelling; possible increased rates of infection and malignancy. (36, 55) |
| Ethambutol | Antimycobacterial: inhibitor of arabinogalactan synthesis, a cell wall component; commonly used in standard antitubercular drug regimens. Tox: dose-dependent ocular dysfunction, dizziness, headache, hyperuricemia. (47) |
| Ethanol | Sedative-hypnotic: acute actions include impaired judgment, ataxia, loss of consciousness, vasodilation, and cardiovascular and respiratory depression. Chronic use leads to dependence and dysfunction of multiple organ systems; fetal alcohol syndrome. Note: zero-order elimination kinetics. (23, 32) |
| Ethinyl estradiol | Synthetic estrogen: used in many hormonal contraceptives. Mestranol is similar. (40) |
| Ethosuximide | Anticonvulsant: used in absence seizures; may block T-type Ca2+ channels in thalamic neurons. Tox: GI distress; safe in pregnancy. (24) |
| Ezetimibe | Antihyperlipidemic: cholesterol-lowering drug that inhibits GI transporter of dietary cholesterol and the cholesterol secreted in bile. Used for hypercholesterolemia, usually in combination with a statin. Tox: possible increased risk of hepatic damage when combined with statin. (35) |
| Fentanyl | Short-acting potent opioid agonist (see morphine) used commonly in anesthesia and for chronic pain (transdermal form). Remifentanil and sufentanil are similar. (25, 31, 32) |
| Finasteride | Antiandrogen: steroid inhibitor of 5α-reductase that inhibits synthesis of dihydrotestosterone. Used in benign prostatic hyperplasia and male-pattern baldness. Dutasteride is similar. (40) |
| Flecainide | Group 1C antiarrhythmic prototype: used in ventricular tachycardia and rapid atrial arrhythmias with Wolff-Parkinson-White syndrome. Tox: arrhythmogenic, CNS excitation. (14) |
| Fluconazole | Imidazole antifungal: inhibits ergosterol synthesis. CNS entry and renal elimination. Used in esophageal and vaginal candidiasis, in coccidioidomycosis, and in the prophylaxis and treatment of fungal meningitis. Adverse effects similar to those of ketoconazole but less severe. (48) |
| Fludrocortisone | Synthetic corticosteroid: high mineralocorticoid and moderate glucocorticoid activity; long duration of action. Used in Addison’s disease. (39) |
| Flumazenil | Benzodiazepine receptor antagonist: used to reverse CNS depressant effects of benzodiazepines, zolpidem, eszopiclone, and zaleplon. (22, 58) |
| Fluorouracil | Antineoplastic: pyrimidine antimetabolite (cell cycle-specific), irreversibly inhibits thymidylate synthase, resulting in dTMP deficiency and “thymine-less” cell death; used mainly for solid tumors. Tox: GI distress, myelosuppression, neurotoxicity. (54) |
| Fluoxetine | Antidepressant: selective serotonin reuptake inhibitor (SSRI) prototype. Less ANS adverse effects and cardiotoxic potential than tricyclics. Tox: CNS stimulation, sexual dysfunction, seizures in overdose, serotonin syndrome. Other SSRIs: citalopram, escitalopram, fluvoxamine, paroxetine, sertraline. (30) |
| Flutamide | Antiandrogen: prototype androgen receptor antagonist used in prostatic carcinoma. Others: bicalutamide, nilutamide. (40) |
| Furosemide | Loop diuretic prototype: blocks Na+/K+/2Cl− transporter in thick ascending limb; high efficacy; used in acute pulmonary edema, refractory edematous states, hypercalcemia, and HTN. Tox: ototoxicity, K+ wasting, hypovolemia, increased serum uric acid. Bumetanide and torsemide differ only in half-life. Ethacrynic acid is similar and can be used in case of sulfa allergy and causes less hyperuricemia. It may reduce uric acid levels. (13, 15) |
| Gabapentin | Anticonvulsant: structural analog of GABA that facilitates its inhibitory actions in the CNS; used for partial seizures, for neuropathic pain, and in bipolar disorder. Tox: sedation, movement disorders. (24, 27) |
| Ganciclovir | Antiviral: effective against herpesviruses (cytomegalovirus [CMV] and herpes simplex virus [HSV]); for CMV requires bioactivation via viral phosphotransferase. Tox: myelosuppression, nephrotoxicity, neurotoxicity. (49) |
| Gemfibrozil | Antihyperlipidemic: fibrate prototype used for hypertriglyceridemia. Lowers serum VLDL and triglycerides and increases HDL by activating peroxisome proliferator-activated receptor-α nuclear receptors. Tox: GI distress, cholelithiasis, increased risk of myopathy when combined with statins or niacin. (35) |
| Gentamicin | Aminoglycoside prototype: bactericidal inhibitor of protein synthesis (30S); active against many aerobic gram-negative bacteria. Narrow therapeutic window; dose reduction required in renal impairment. Tox: renal dysfunction, ototoxicity; once-daily dosing is effective (postantibiotic effect) and less toxic. Amikacin and tobramycin are similar. (45, 51) |
| Glipizide | Oral antidiabetic: second-generation, potent sulfonylurea secretagogue. Blocks K+ channels in pancreatic B cells, causing depolarization and release of insulin. Tox: hypoglycemia, weight gain. Related drugs: glyburide and older sulfonylureas such as chlorpropamide and tolbutamide; short-acting secretagogues include repaglinide and nateglinide. (41) |
| Glucagon | Hormone from pancreatic A cells. Increases blood glucose via a GPCR Gs and cAMP. Used in severe hypoglycemia and as an antidote in β-blocker overdose. (41, 58) |
| Haloperidol | Antipsychotic butyrophenone: blocks brain dopamine D2 receptors. Tox: marked EPS dysfunction, hyperprolactinemia; fewer ANS adverse effects than phenothiazines. (29) |
| Halothane | General anesthetic prototype: inhaled halogenated hydrocarbon. Tox: cardiovascular and respiratory depression and relaxation of skeletal and smooth muscle. Use is declining because of sensitization of heart to catecholamines and occurrence (rare) of hepatitis. Other inhaled anesthetics: isoflurane, sevoflurane, desflurane, enflurane. Compare nitrous oxide. (25) |
| Heparin | Anticoagulant: large polymeric molecule with activity against thrombin and factor X. Rapid onset, parenteral administration. LMW heparins (eg, enoxaparin) and fondaparinux have a similar mechanism of action (accelerates activity of antithrombin III), although they are more selective for factor X. Tox: bleeding. Antidote: protamine. (34) |
| Hexamethonium | Prototypic ganglion blocker, now obsolete except for research use. Causes marked block of both PANS and SANS, hypotension. Newer analogs trimethaphan, mecamylamine are rarely used. (6) |
| Hydralazine | Antihypertensive: arteriolar vasodilator, orally active; used in severe HTN, HF. Minoxidil, a similar but more powerful antihypertensive, is also used topically in baldness. Tox: tachycardia, salt and water retention, lupus-like syndrome (hydralazine). (11, 13) |
| Hydrochlorothiazide | Thiazide diuretic prototype: acts in distal convoluted tubule to block Na+/Cl− transporter; used in HTN, HF, nephrolithiasis. Chlorthalidone is similar. Tox: hypersensitivity reactions; increased serum lipids, uric acid, glucose; K+ wasting. (11, 13, 15) |
| Hydroxychloroquine | DMARD: immunosuppressant used for rheumatoid arthritis. Tox: rash, GI distress, ocular toxicity, myopathy, neuropathy. Other DMARDs: methotrexate, sulfasalazine, gold salts, penicillamine. (36) |
| Ibuprofen | NSAID: nonselective COX inhibitor with analgesic, antipyretic, and anti-inflammatory actions similar to aspirin, but no low-dose antiplatelet effect. Tox: GI, renal. (36) |
| Imipenem | Prototype carbapenem antibiotic: active against many aerobic and anaerobic bacteria, including penicillinase-producing organisms; a bactericidal inhibitor of cell wall synthesis. Used with cilastatin (which inhibits metabolism by renal dehydropeptidases). Tox: allergy (partial cross-reactivity with penicillins), seizures. Meropenem and ertapenem are similar but do not require cilastatin and are less likely to cause seizures. (43) |
| Imipramine | Tricyclic antidepressant (TCA): blocks reuptake of norepinephrine and serotonin. Tox: atropine-like, postural hypotension, sedation, cardiac arrhythmias in overdose, additive effects with other CNS depressants. Other TCAs: amitriptyline, clomipramine, doxepin. (30) |
| Indinavir | Antiviral: HIV protease inhibitor (PI) used as a component of combination regimens in AIDS. Tox: anemia, nephrolithiasis, metabolic disorders, inhibits P450 drug metabolism. Other PIs: amprenavir, nelfinavir, ritonavir (major P450 inhibitor, see below), and saquinavir. (49) |
| Indomethacin | NSAID: highly potent. Usually reserved for acute inflammation (eg, acute gout), neonatal patent ductus arteriosus. Tox: GI toxicity, renal damage. (36) |
| Interferon-` | Cytokine: treatment of hepatitis B and C viral infections and some malignancies. Tox: “flu-like” syndrome, myelosuppression, neurotoxicity. (49, 55) |
| Ipratropium | Antimuscarinic agent: aerosol for asthma, chronic obstructive pulmonary disease (COPD). Good bronchodilator in 30–60% of patients. Tiotropium and aclidinium are similar with longer action; approved only for COPD. Not as efficacious as β2 agonists but less toxic in COPD. Tox: dry mouth. (8, 20) |
| Isoniazid | Antimycobacterial: primary drug in combination regimens for tuberculosis; used as sole agent in treatment of latent infection. Metabolic clearance via N-acetyltransferases (genetic variability). Tox: hepatotoxicity (age-dependent), peripheral neuropathy (reversed by pyridoxine), hemolysis (in glucose-6-phosphate dehydrogenase deficiency [G6PD] deficiency). (47) |
| Isoproterenol | Beta1 and β2 agonist catecholamine prototype: bronchodilator, cardiac stimulant. Always causes tachycardia because both direct and reflex actions increase HR. Tox: arrhythmias, tremor, angina. (9) |
| Ivermectin | Antihelminthic: drug of choice for onchocerciasis and threadworm infections. Intensifies GABA-mediated neurotransmission in nematodes, but no CNS access in humans. Tox: in onchocerciasis causes headache, fever, hypotension, joint pain. (53) |
| Ketoconazole | Antifungal azole prototype: active systemically; inhibits the synthesis of ergosterol. Used for C albicans, dermatophytosis, and non-life-threatening systemic mycoses. Is sometimes used to suppress adrenocorticoid or gonadal hormone synthesis. Tox: hepatic dysfunction, inhibits steroid synthesis and P450-dependent drug metabolism. Others: fluconazole, itraconazole, and voriconazole have a wider spectrum and less inhibitory effects on hepatic cytochromes P450. (39, 40, 48) |
| Ketorolac | NSAID: mainly used as a systemic analgesic; only NSAID available in parenteral form; see also aspirin. (36) |
| Lamivudine | Nucleoside reverse transcriptase inhibitor (NRTI) also known as 3TC. Least toxic NRTI. Notable for use in chronic hepatitis B in addition to HIV infection. (49) |
| Lamotrigine | Antiepileptic drug for absence and partial seizures; also used in bipolar affective disorder. Tox: rash, possibly life threatening, especially in pediatric patients. (24, 29) |
| Latanoprost | Prostaglandin F2α analog used topically in glaucoma. Bimatoprost and travoprost are similar. (18) |
| Lepirudin | Antithrombotic: recombinant form of a medicinal leech protein that directly inhibits thrombin; rapid onset; parenteral administration. Used in heparin-induced thrombocytopenia (HIT). Tox: bleeding; monitor with aPTT. Bivalirudin is similar, used for PCI. Argatroban is a small molecule used parenterally for PCI. Dabigatran is an oral thrombin inhibitor. (34) |
| Leuprolide | GnRH analog: continuous therapy used to suppress gonadotropin and gonadal hormone synthesis, especially in concert with gonadotropins for ovulation induction and in advanced prostate cancer. Goserelin and nafarelin are similar. Ganirelix is a GnRH receptor antagonist with similar effects. Tox: hot flushes, decreased bone density with prolonged use, gynecomastia (men). (37, 40, 54) |
| Levodopa | Dopamine precursor: used in parkinsonism, usually in combination with carbidopa (a peripheral inhibitor of dopamine metabolism). Tox: dyskinesias, hypotension, on-off phenomena, behavioral changes. (28) |
| Levofloxacin | Fluoroquinolone: Bactericidal inhibitor of topoisomerases; one of several “respiratory” fluoroquinolones (gemifloxacin, moxifloxacin) with greater activity than ciprofloxacin against pneumococci. Tox: see ciprofloxacin. (46) |
| Levonorgestrel | Progestin: used in many contraceptives including combined oral contraceptives, progestin-only oral contraceptives, the levonorgestrel IUD, subcutaneous implants, and the Plan B emergency contraceptive. (40) |
| Levothyroxine (T4) | Used for hypothyroidism. MOA: activation of nuclear receptors; T4 is converted to T3 in the target cells, the liver, and the kidneys. (38) |
| Lidocaine | Amide local anesthetic, medium-duration amide prototype: highly selective use-dependent group 1B antiarrhythmic; used for nerve block and acute post-MI ischemic ventricular arrhythmias. Parenteral only. Tox: CNS excitation. Mexiletine: like lidocaine, but orally active, longer duration. (14, 26) |
| Lithium | Antimanic prototype: a primary drug in mania and bipolar affective disorders; blocks recycling of the phosphatidylinositol second messenger system. Tox: tremor, diabetes insipidus, goiter, seizures (in overdose). (29) |
| Loratadine | Second-generation H1 antihistamine: used in hay fever. Tox: much less sedation than first-generation antihistamines; no ANS effects. Others: desloratadine, cetirizine, fexofenadine. (16) |
| Losartan | Angiotensin AT1 receptor blocker (ARB) prototype: used in HTN. Effects and toxicity similar to those of ACE inhibitors but causes less cough. Other AT1 blockers: candesartan, eprosartan, irbesartan, olmesartan, telmisartan, valsartan. (11, 13, 17) |
| Lovastatin | Antihyperlipidemic: HMG-CoA reductase inhibitor prototype used for hypercholesterolemia. Acts in liver to reduce synthesis of cholesterol and indirectly increase LDL receptor synthesis. Other statins: atorvastatin, fluvastatin, pravastatin, rosuvastatin, simvastatin. Tox: hepatotoxicity (elevated enzymes), muscle damage, teratogen. (35) |
| Malathion | Organophosphate insecticide cholinesterase inhibitor: prodrug converted to malaoxon. Less toxic in mammals and birds because metabolized to inactive products. Other organophosphates: parathion converted to paraoxon, and the nerve gases (eg, sarin, soman). (7, 56) |
| Mannitol | Osmotic diuretic: used short term for reduction of intracranial pressure or to promote excretion of renal toxins in hemolysis, rhabdomyolysis. Tox: initial expansion of extracellular fluid volume with resulting hyponatremia, headache, nausea. With continued use, dehydration and hypernatremia. (15) |
| Mebendazole | Antihelminthic: important drug for common nematode infections. Inhibits microtubule synthesis and glucose uptake in nematodes. Tox: GI distress, caution in pregnancy. Albendazole (widely used) and thiabendazole (more toxic) are related antihelminthics. (53) |
| Medroxyprogesterone | Progestin: used in combination with an estrogen for treatment of menopausal symptoms and used as a long-acting injection (Depo-Provera) for contraception. (40) |
| Mefloquine | Antimalarial: unknown mechanism of action. Used for prophylaxis against and treatment of chloroquine-resistant malaria, but resistance emerging. Tox: GI distress, dizziness, seizures in overdose, arrhythmias. (52) |
| Meperidine | Opioid analgesic: synthetic, equivalent to morphine in efficacy but orally bioavailable. Strong agonist at μ opioid receptors; blocks muscarinic receptors; serotonergic activity. Tox: see morphine; normeperidine accumulation may cause seizures, serotonin syndrome with SSRIs. (31) |
| Metformin | Oral antidiabetic: prototype biguanide; inhibits hepatic and renal gluconeogenesis, minimal hypoglycemia or weight gain. Tox: GI distress, lactic acidosis possible but rare. (41) |
| Methadone | Opioid analgesic: synthetic μ agonist, equivalent to morphine in efficacy but orally bioavailable and with a longer half-life. Used as analgesic, to suppress withdrawal symptoms, and in maintenance programs. Tox: see morphine. (31, 32) |
| Methimazole | Antithyroid drug: inhibits tyrosine iodination and coupling reactions; orally active. Tox: rash, agranulocytosis (rare). Propylthiouracil is similar. (38) |
| Methotrexate | Antineoplastic, DMARD, immunosuppressant: cell cycle-specific drug that inhibits dihydrofolate reductase. Major dose reduction required in renal impairment. Tox: GI distress, myelosuppression, crystalluria. Leucovorin rescue used to reduce toxicity. (36, 54, 55) |
| Methyldopa | Antihypertensive: safe during pregnancy, prodrug of methylnorepinephrine, a CNS-active α2 agonist. Reduces SANS outflow from vasomotor center. See also clonidine. Tox: sedation, positive Coombs test, hemolysis. (11) |
| Metoclopramide | Prokinetic agent: dopamine D2 receptor antagonist used to stimulate upper GI motility in patients with gastroparesis and used as an antiemetic. Tox: restlessness, insomnia, agitation, extrapyramidal effects, elevated prolactin. (59) |
| Metronidazole | Antiprotozoal antibiotic: drug of choice in extraluminal amebiasis and trichomoniasis (tinidazole is equivalent); effective against bacterial anaerobes, including B fragilis and in antibiotic-induced colitis resulting from C difficile. Tox: peripheral neuropathy, GI distress, ethanol intolerance, mutagenic potential. (50, 52) |
| Mifepristone | Progestin and glucocorticoid receptor antagonist: used in combination with prostaglandin analogs for medical abortion in early pregnancy. (39, 40) |
| Misoprostol | Prostaglandin E1 derivative: orally active prostaglandin used to prevent GI ulcers caused by NSAIDs. Also used with mifepristone as abortifacient. Tox: diarrhea. (18, 40, 59) |
| Montelukast | Leukotriene receptor blocker (especially LTD4) used for prophylaxis in asthma. Orally active; once daily administration. Zafirlukast is similar. Tox: minimal. (20) |
| Morphine | Opioid analgesic prototype: strong μ receptor agonist. Poor oral bioavailability. Tox: constipation, emesis, sedation, respiratory depression, miosis, and urinary retention. Tolerance may be marked; high potential for psychological and physiologic dependence. Additive effects with other CNS depressants. (31, 32) |
| Nafcillin | Penicillinase-resistant penicillin: narrow spectrum, used for suspected or known staphylococcal infections; not active against methicillin-resistant S aureus (MRSA). Tox: penicillin allergy. Others in group include methicillin (the prototype, rarely used), oxacillin, cloxacillin, dicloxacillin. (43, 51) |
| Naloxone | Opioid μ receptor antagonist: used to reverse CNS depressant effects of opioid analgesics (overdose or when used in anesthesia). Naltrexone (orally active), a related compound, is used in ethanol dependency states. (23, 31, 58) |
| Neostigmine | Cholinesterase inhibitor: prototype synthetic quaternary nitrogen carbamate with little CNS effect. Tox: excess cholinomimetic effects. Pyridostigmine is similar but longer-acting. Physostigmine is a lipid-soluble plant alkaloid. Echothiophate is a rarely used organophosphate cholinesterase inhibitor for topical ophthalmic use. (7, 27) |
| Niacin | Antihyperlipidemic, vitamin: inhibits VLDL synthesis and release of fatty acids from adipose tissue. Lowers LDL cholesterol and triglycerides and raises HDL cholesterol. Tox: flushing, pruritus, liver dysfunction, increased risk of myopathy when combined with statins. (35) |
| Nifedipine | Dihydropyridine calcium channel blocker prototype: less cardiac depression than verapamil, diltiazem; used in angina, HTN. Tox: constipation, headache, tachycardia, arrhythmias (avoid rapid-onset forms, that trigger reflex tachycardia). Others in the dihydropyridine group include amlodipine, felodipine, nicardipine. (11, 12) |
| Nitric oxide (NO) | Endogenous vasodilator released from vascular endothelium; neurotransmitter. Mediates vasodilating effect of acetylcholine, histamine, and hydralazine. Active metabolite of nitroprusside and of nitrates used in angina. Used as pulmonary dilator in neonatal hypoxia, pulmonary HTN. Tox: excessive vasodilation, hypotension. (19) |
| Nitroglycerin | Antianginal vasodilator prototype: releases nitric oxide (NO) in veins, less in arteries, and causes smooth muscle relaxation. Standard of therapy in angina (both atherosclerotic and variant). Tox: tachycardia, orthostatic hypotension, headache. Oral nitrates: isosorbide dinitrate, isosorbide mononitrate. (12, 13) |
| Nitrous oxide | Gaseous anesthetic, very low potency (MAC > 100%) but very low toxicity. |
| Norepinephrine | Adrenoceptor agonist prototype, neurotransmitter: acts at all α adrenoceptors and β1 adrenoceptors; used as vasoconstrictor. Causes reflex bradycardia. Tox: ischemia, arrhythmias, HTN. (6, 9) |
| Olanzapine | Atypical antipsychotic: high-affinity antagonist at 5-HT2a receptors with minimal extrapyramidal side effects; improves both positive and negative symptoms of schizophrenia. Tox of most atypicals: weight gain, type II diabetes, hyperlipidemia, increased prolactin. Other atypicals: quetiapine (short half-life), risperidone (possible EPS dysfunction), sertindole (QT prolongation), clozapine (agranulocytosis). (29) |
| Omeprazole | Proton pump inhibitor prototype: irreversible blocker of H+/K+ ATPase proton pump in parietal cells of stomach. Used in GI ulcers, Zollinger-Ellison syndrome, gastroesophageal reflux disease (GERD). Other “prazoles”: esomeprazole, dexlansoprazole, lansoprazole, pantoprazole, rabeprazole. Tox: hypergastrinemia. (59) |
| Ondansetron | 5-HT3 receptor blocker prototype: very important antiemetic for cancer chemotherapy; also used postoperatively to reduce vomiting. Tox: extrapyramidal effects. Other “setrons”: dolasetron, granisetron, palonosetron. (16, 59) |
| Oseltamivir | Antiviral, oral: neuraminidase inhibitor blocking release of mature virions of influenza A and B and decreasing their infectivity. Prophylactic and shortens duration of flu symptoms. Zanamivir, inhaled, is similar in action and use. (49) |
| Oxybutynin | Muscarinic cholinoceptor blocker: used to relieve bladder spasm and incontinence. Tolterodine, weaker but more selective for M3 receptors, has similar uses. (8) |
| Paclitaxel | Antineoplastic plant alkaloid: cell cycle (M phase)-specific agent; inhibits mitotic spindle disassembly. Tox: hematotoxicity, peripheral neuropathy, hypersensitivity reactions. Docetaxel is similar. (54) |
| Penicillamine | Chelator, immunomodulator: treatment of copper poisoning and Wilson’s disease, and formerly used in rheumatoid arthritis. (36, 57) |
| Penicillin G | Penicillin prototype: active against common streptococci, gram-positive bacilli, gram-negative cocci, spirochetes (drug of choice in syphilis), and enterococci (if used with an aminoglycoside); penicillinase susceptible. Tox: penicillin allergy. (43, 51) |
| Phenelzine | Irreversible nonselective MAO inhibitor. Backup drug for atypical depression. Tox: Malignant hypertension with indirect-acting sympathomimetics and tyramine, serotonin syndrome with serotonergic drugs. (30) |
| Phenobarbital | Long-acting barbiturate: used as a sedative and for tonic-clonic seizures. Facilitates GABA-mediated neuronal inhibition (by increasing duration of channel opening) and may block excitatory neurotransmitters. Partial renal clearance that can be increased by urinary alkalinization. Chronic use leads to induction of liver drug-metabolizing enzymes and ALA synthase. Tox: psychological and physiologic dependence; additive effects with other CNS depressants. (22, 24) |
| Phenoxybenzamine | Alpha-blocker prototype (nonselective): irreversible action. Phentolamine: similar with competitive action. Used in pheochromocytoma. Tox: excess hypotension; GI distress. (10) |
| Phenytoin | Anticonvulsant: used for tonic-clonic and partial seizures; blocks Na+ channels in neuronal membranes. Serum levels variable because of first-pass metabolism and nonlinear elimination kinetics. Tox: sedation, diplopia, gingival hyperplasia, hirsutism, teratogenic potential (fetal hydantoin syndrome). Drug interactions via effects on plasma protein binding or induction of hepatic metabolism. Phenytoin follows nonlinear (or zero-order) kinetics at therapeutic concentrations. (24) |
| Pilocarpine | Muscarinic receptor partial agonist prototype: tertiary amine alkaloid. May cause paradoxic hypertension by activating muscarinic excitatory postsynaptic receptors in postganglionic sympathetic neurons. Used in Sjögren’s syndrome, xerostomia, glaucoma. Tox: muscarinic excess. (7) |
| Piperacillin | Extended-spectrum penicillin active against selected gram-negative bacteria, including Pseudomonas aeruginosa (synergistic with aminoglycosides). Susceptible to penicillinases unless used with tazobactam. Tox: penicillin allergy. (43) |
| Pralidoxime | Acetylcholinesterase regenerator: antidote (with atropine) for organophosphate poisoning; chemical antagonist with very high affinity for phosphorus in organophosphates. Tox: neuromuscular weakness. (8, 58) |
| Pramipexole | Dopamine D3 receptor agonist in CNS (ropinirole similar but higher affinity for D2 receptors): often a first-line drug in parkinsonism. Tox: postural hypotension, dyskinesias (both drugs less toxicity than the ergot bromocriptine). (28) |
| Praziquantel | Antihelminthic: important drug for trematode (fluke) and cestode (tapeworm) infections. Increases membrane permeability to Ca2+ causing muscle contraction followed by paralysis. Tox: headache, dizziness, GI distress, fever; potential abortifacient. (53) |
| Prazosin | Alpha1-selective blocker prototype: used in HTN and benign prostatic hyperplasia. Tox: first-dose orthostatic hypotension but less reflex tachycardia than nonselective α blockers. Other “osins”: terazosin, doxazosin. Tamsulosin is similar but used only in benign prostatic hyperplasia. (10, 11) |
| Prednisone | Glucocorticoid prototype: potent, short acting; less mineralocorticoid activity than cortisol but more than dexamethasone, betamethasone, or triamcinolone. (20, 36, 39, 54, 55) |
| Probenecid | Uricosuric: inhibitor of renal weak acid secretion and reabsorption in proximal tubule; prolongs half-life of some antimicrobial drugs, accelerates clearance of uric acid. Used in gout due to underexcretion. Sulfinpyrazone is similar. (36) |
| Procainamide | Group 1A antiarrhythmic drug prototype: short half-life, metabolized by N-acetyltransferase. Tox: may cause a lupus-like syndrome and torsades de pointes arrhythmia. Similar to quinidine but more cardiodepressant. (14) |
| Propranolol | Nonselective β-blocker prototype: local anesthetic action but no partial agonist effect. Used in HTN, angina, arrhythmias (group 2), migraine, hyperthyroidism, tremor. Tox: asthma, AV block, HF. (8, 11, 14, 28, 38) |
| Propylthiouracil (PTU) | Used for hyperthyroidism. Inhibits thyroid peroxidase reactions, iodine organification, and peripheral conversion of T4 to T3. Orally administered. Adverse effects: nausea, GI upset, rash, agranulocytosis, hepatitis, hypothyroidism. (38) |
| Prostacyclin | PGI2: endogenous prostaglandin vasodilator and inhibitor of platelet aggregation. An analog, epoprostenol, is used in primary pulmonary HTN. (18) |
| Pyrimethamine | Antiprotozoal: antifolate that inhibits DHF reductase and synergistic, via sequential blockade, with sulfadiazine against Toxoplasma gondii. Folinic acid is needed to offset hematologic toxicity. (46, 52) |
| Quinine | Antimalarial: blood schizonticide; no effect on liver stages. Interferes with nucleic acid metabolism in plasmodium. Isomer of quinidine. Tox: cinchonism, GI upset. (52) |
| Ramelteon | Hypnotic: agonist at brain melatonin receptors; not a controlled substance. Tox: fatigue, increased prolactin and decreased testosterone. (22) |
| Reserpine | Antihypertensive (rarely used): selective inhibitor of vesicle catecholamine-H+ antiporter (VMAT); obsolete use in HTN, causes depletion of catecholamines and 5-HT from their stores. Tox: severe depression, suicide, ulcers, diarrhea. (6, 11) |
| Rifampin | Antimicrobial: inhibitor of DNA-dependent RNA polymerase used in drug regimens for tuberculosis and the meningococcal carrier state. Tox: hepatic dysfunction, induction of liver drug-metabolizing enzymes (drug interactions), flu-like syndrome with intermittent dosing. Rifabutin is similar but associated with fewer drug interactions. (47) |
| Ritonavir | Antiviral: HIV protease inhibitor (PI) used at low dose as a component of combination regimens in AIDS to inhibit metabolism of other drugs (See indinavir). Tox: implicated in many drug interactions when used as sole PI. (49) |
| Rosiglitazone | Oral antidiabetic: thiazolidinedione stimulator of peroxisome proliferator-activator receptors (PPAR-gamma) and enhances target tissue sensitivity to insulin. Less hypoglycemia and weight gain than secretagogue antidiabetics. Tox: fluid retention, heart failure, fractures in women. Pioglitazone is similar. (41) |
| Rivaroxaban | Oral factor X inhibitor: used for prevention of deep venous thrombosis (DVT), pulmonary embolism (PE), postsurgery, and stroke in atrial fibrillation. Fixed dose, no routine monitoring. Side effect: bleeding. No specific reversal agent. Apixaban is similar. (34) |
| Selegiline | MAO-B inhibitor: selective inhibitor of the enzyme that metabolizes dopamine (no tyramine interactions at normal dosage). Used in Parkinson’s disease. Tox: GI distress, CNS stimulation, dyskinesias, serotonin syndrome if used with selective serotonin reuptake inhibitors. Rasagiline is similar and used more commonly. (28) |
| Sildenafil | Inhibits phosphodiesterase (PDE)-5, preventing breakdown of cyclic guanosine monophosphate (cGMP), which promotes vasodilation and smooth muscle relaxation. Used for erectile dysfunction and pulmonary hypertension. Tadalafil and vardenafil are similar. Tox: severe hypotension when combined with nitrates, impaired blue-green color vision. (12) |
| Sotalol | Group 3 antiarrhythmic prototype: blocks IK channels and α receptors. Used for atrial and ventricular arrhythmias. Tox: torsades de pointes arrhythmias. Others in group: ibutilide, dofetilide. (14) |
| Spironolactone | Aldosterone receptor antagonist: K+-sparing diuretic action in the collecting tubules; used in aldosteronism, HTN, and female hirsutism (androgen receptor-blocking action). Tox: hyperkalemia, gynecomastia. Eplerenone, used in HTN and heart failure, is a more selective aldosterone antagonist. (13, 15, 39, 40) |
| Streptogramins | Antibiotics: the combination of quinupristin and dalfopristin; bactericidal inhibitors of protein synthesis. Intravenous use for drug-resistant gram-positive cocci including MRSA (methicillin-resistant S aureus), VRE (vancomycin-resistant enterococci), and pneumococci. Tox: infusion-related pain, arthralgia, myalgia. Linezolid is another inhibitor of protein synthesis used for drug-resistant gram-positive cocci, including PRSP (penicillin-resistant S pneumoniae) strains. (44) |
| Succinylcholine | Depolarizing neuromuscular relaxant prototype: short duration (5 min) if patient has normal plasma cholinesterase (genetically determined). No antidote (compare with tubocurarine). Implicated in malignant hyperthermia. (7, 27) |
| Sulfasalazine | 5-Aminosalicylate (5-ASA) anti-inflammatory drug: used for inflammatory bowel disease (IBD) and rheumatoid arthritis. Tox: rash, GI disturbances, leukopenia. Other 5-ASA drugs used for IBD are mesalamine, balsalazide, olsalazine. (36, 59) |
| Sumatriptan | 5-HT1D receptor agonist: used to abort migraine attacks. Tox: coronary vasospasm, chest pain or pressure. Six other triptans are currently available. (16) |
| Tamoxifen | Selective estrogen receptor modulator (SERM): blocks estrogen receptors in breast tissue; activates endometrial receptors. Used in estrogen receptor-positive cancers, possibly prophylactic in high-risk patients. Toremifene is similar. Raloxifene is approved for osteoporosis, activates bone estrogen receptors, but is an antagonist of breast and endometrial receptors. (40, 54) |
| Terbinafine | Antifungal: fungicidal inhibitor of squalene epoxidase. Most effective agent in onychomycosis, oral and topical forms. Tox: GI upsets, headache, rash. (48) |
| Teriparatide | Recombinant truncated form of PTH for parenteral treatment of osteoporosis. Increases bone formation and bone resorption; during first 6 months net gain in bone. Side effects: hypercalcemia and hypercalciuria. Only approved for 2 yr of use due to risk of osteosarcoma. (42) |
| Tetracycline | Antibiotic: tetracycline prototype; bacteriostatic inhibitor of protein synthesis (30S). Broad spectrum, but many resistant organisms. Used for mycoplasmal, chlamydial, rickettsial infections, chronic bronchitis, acne, cholera; a backup drug in syphilis. Tox: GI upset and superinfections, Fanconi’s syndrome, photosensitivity, dental enamel dysplasia. Other tetracyclines include doxycycline (see above) and tigecycline (IV) used for multidrug-resistant nosocomial pathogens. (44) |
| Theophylline | Methylxanthine derivative found in tea; used in asthma. Bronchodilator, mild CNS stimulant. Caffeine (coffee) and theobromine (cocoa) are similar. Tox: seizures. (20) |
| Trimethoprim-sulfamethoxazole (TMP-SMZ) | Antimicrobial drug combination: causes synergistic sequential blockade of folic acid synthesis. Active against many gram-negative bacteria, including Aeromonas, Enterobacter, H influenzae, Klebsiella, Moraxella, Salmonella, Serratia, and Shigella. Tox: mainly due to sulfonamide; includes hypersensitivity, myelotoxicity, kernicterus, and drug interactions caused by competition for plasma protein binding. (46, 52) |
| Tubocurarine | Nondepolarizing neuromuscular blocking agent prototype: competitive nicotinic blocker. Analogs: pancuronium, atracurium, vecuronium, and other “-curiums” and “-oniums.” Tox: respiratory paralysis. Releases histamine and may cause hypotension, therefore rarely used. Antidote: cholinesterase inhibitor, for example, neostigmine. (8, 27) |
| Tyramine | Indirect-acting sympathomimetic prototype: releases or displaces norepinephrine from stores in nerve endings. Presence in certain foods may cause potentially lethal hypertensive responses in patients taking MAO inhibitors. (6) |
| Valproic acid | Anticonvulsant: primary drug in absence, clonic-tonic, and myoclonic seizure states. Also used commonly for bipolar disorder. Tox: GI distress, hepatic necrosis (rare), teratogenic (spina bifida), inhibits drug metabolism. (24, 29) |
| Vancomycin | Glycopeptide bactericidal antibiotic: inhibits synthesis of cell wall precursor molecules. A drug of choice for methicillin-resistant staphylococci and effective in antibiotic-induced colitis. Dose reduction required in renal impairment (or hemodialysis). Tox: ototoxicity, hypersensitivity, renal dysfunction (rare). (43, 51) |
| Verapamil | Calcium channel blocker prototype: blocks L-type channels; cardiac depressant and vasodilator; used in HTN, angina, and arrhythmias (group 4). Tox: AV block, HF, constipation. Diltiazem, like verapamil, has more depressant effect on heart than dihydropyridines (eg, nifedipine). (11, 12, 14) |
| Vincristine | Antineoplastic: cell cycle (M phase)-specific plant alkaloid; inhibits mitotic spindle formation. Tox: peripheral neuropathy. Vinblastine, a congener, causes myelosuppression. (54) |
| Warfarin | Oral anticoagulant prototype: causes synthesis of nonfunctional versions of the vitamin K-dependent clotting factors (II, VII, IX, X). Measure with PT test expressed as INR. Tox: bleeding, teratogenic. Antidote: vitamin K, fresh plasma. (34) |
| Zidovudine (ZDV) | Antiviral: prototype NRTI used in combinations for HIV infections and in prophylaxis for needlesticks and vertical transmission. Tox: severe myelosuppression. Other NRTIs: abacavir, didanosine (ddI), lamivudine (3TC), stavudine (d4T), zalcitabine (ddC). (49) |
| Zolpidem | Nonbenzodiazepine hypnotic: acts via the BZ1 receptor subtype and is reversed by flumazenil; less amnesia and muscle relaxation and lower dependence liability than benzodiazepines. Zaleplon and eszopiclone are similar. (22) |