Chapter 22: Sedative-Hypnotic Drugs
This drug is used in the management of insomnia and facilitates the inhibitory actions of GABA, but it lacks anticonvulsant or muscle-relaxing properties and has minimal effect on REM sleep. Its actions are antagonized by flumazenil.
Only two of the drugs listed are used for insomnia, eszopiclone and ramelteon. Eszopiclone, zaleplon, and zolpidem are related hypnotics that, though structurally different from benzodiazepines, appear to have a similar mechanism of action. However, unlike benzodiazepines, these drugs are not used in seizures or in muscle spasticity states. Compared with benzodiazepines, the newer hypnotics are less likely to alter sleep patterns. Ramelteon activates melatonin receptors in the suprachiasmatic nuclei; flumazenil does not reverse its effects. Buspirone is not a hypnotic! The answer is C.
Which statement concerning the barbiturates is most 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 ...