A patient is admitted to the emergency department with signs and symptoms that could be due to either a muscarinic stimulant or an opioid. Which of the following is a common effect of both muscarinic stimulant drugs and opioids?
(A) Decreased peristalsis
(B) Decreased secretion by salivary glands
(D) Inhibition of thermoregulatory sweat glands
E (7, 31) Neither opioids nor muscarinic agonists decrease salivation, decrease sweating, or raise blood pressure. Opioids decrease peristalsis; muscarinics increase it. Both drug groups can cause miosis.
Which statement about nitric oxide is most correct?
(A) Nitric oxide is synthesized in vascular endothelium and the brain
(B) Nitric oxide is released from storage vesicles by acetylcholine
(C) Nitric oxide synthase is stimulated by nitroprusside
(D) Nitric oxide synthase is inhibited by histamine
(E) Nitric oxide causes pulmonary vasoconstriction
A (19) Nitric oxide (NO) is not stored; it is synthesized on demand in response to acetylcholine, histamine, and other drugs in several tissues, including brain and endothelium. NO is released from the nitroprusside molecule.
A 35-year-old patient is brought to the emergency department in a drug-induced coma. Blood samples taken over the next several hours show a declining drug concentration, as shown in the graph below. Which of the following drugs is the most likely cause of this patient’s coma?
B (1) The graph shows first-order elimination of the drug in question (note ordinate is a log scale). Aspirin, ethanol, and phenytoin are eliminated mainly by zero-order kinetics. Diazepam is the only drug in the list that is eliminated by first-order kinetics.
In a laboratory study of a new agent, the activity of a membrane-bound enzyme was found to be increased by the drug. Analysis of this enzyme molecule revealed that it is an integral tyrosine kinase, the extracellular domain of which binds ligands while the intracellular domain phosphorylates tyrosine residues. Which of the following receptors communicate their activation by turning on an integral intracellular tyrosine kinase domain?
(A) Acetylcholine nicotinic receptors