Chapter 22: Sedative-Hypnotic Drugs
A 52-year-old woman is seen by you in the sleep clinic for long-standing insomnia. Which of the following would you prescribe, because 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.
A 24-year-old man was found unresponsive with an empty bottle of phenobarbital pills next to him. He was rushed to the ED. Which statement concerning management of this patient is most accurate?
(A) Acidification of the urine accelerates the elimination of phenobarbital
(B) Alkalinization of the urine accelerates the elimination of phenobarbital
(C) Flumazenil will reverse the effects of phenobarbital
(D) Compared with phenobarbital, the benzodiazepines exhibit a steeper dose-response relationship
(E) Respiratory depression caused by barbiturate overdosage can be reversed by flumazenil
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. Flumazenil is an antagonist at BZ receptors and is used to reverse CNS depressant effects of benzodiazepines. The dose-response curve for benzodiazepines is flatter than that for barbiturates such as phenobarbital. 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