Chapter 22: Sedative-Hypnotic Drugs
A 43-year-old very overweight man complains of not sleeping well and feeling tired during the day. He says that his wife is the cause of the problem because she wakes him up several times during the night because of his loud snores. This appears to be a breathing-related sleep disorder, so you should probably write a prescription for
Benzodiazepines and barbiturates are contraindicated in breathing-related sleep disorders because they further compromise ventilation. In obstructive sleep apnea (pickwickian syndrome), obesity is a major risk factor. The best prescription you can give this patient is to lose weight. The answer is E.
Which statement concerning the barbiturates is accurate?
(A) Abstinence syndromes are more severe during withdrawal from phenobarbital than from secobarbital
(B) Alkalinization of the urine accelerates the elimination of phenobarbital
(C) Barbiturates may increase the half-lives of drugs metabolized by the liver
(D) Compared with barbiturates, the benzodiazepines exhibit a steeper dose-response relationship
(E) Respiratory depression caused by barbiturate overdosage can be reversed by flumazenil
Withdrawal symptoms from use of the shorter-acting barbiturate secobarbital are more severe than with phenobarbital. The dose-response curve for benzodiazepines is flatter than that for barbiturates. Induction of liver drug-metabolizing enzymes occurs with barbiturates and may lead to decreases in half-life of other drugs. Flumazenil is an antagonist at BZ receptors and is used to reverse CNS depressant effects of benzodiazepines. As a weak acid (pKa 7), phenobarbital will be more ionized (nonprotonated) in the urine at alkaline pH and less reabsorbed in the renal tubule. The answer is B.
A 24-year-old stockbroker has developed a “nervous disposition.” He is easily startled, worries about inconsequential matters, and sometimes complains of stomach cramps. At night he grinds his teeth in his sleep. There is no history of drug abuse. Diagnosed as suffering from generalized anxiety disorder, he is prescribed buspirone. The patient should be informed to anticipate
(A) A need to continually increase drug dosage because of tolerance
(B) A significant effect of the drug on memory
(C) Additive CNS depression with alcoholic beverages
(D) That the drug is likely to take ...