Name: Flurazepam (Dalmane)
Class: Antianxiety-Sedative-Hypnotic Agent (Benzodiazepine)
Mechanism: Acts on BZD receptors closely coupled to GABAA receptors ® enhancement of GABA inhib. action via freq. of Cl- channel opening.
Absorption: Oral ® rapid absorption (large variability in indiv. responsiveness).
Dist.: Protein binding ³50%. CNS.
Metabolism.: Liver microsomal N-dealkylation/hydroxylation, then conjug ® inactive glucuronides. No induction of hepatic microsomal enzymes.
Excretion, t½: Urine—mostly Metabolismolized. Long—24-100 hr. Active Metabolismolites.
Toxicity/S.E.s: Acute—excessive depression of CNS fxns (drowsiness, sleep, confusion, disorientation, ataxia, slurred speech, nystagmus, mild amnesia, dementia). May also cause aggression, hyperactivity, delirium, insomnia. Large doses or mixture w/depressants (e.g., EtOH) may cause resp. depression, coma, hallucinations, nightmares, confusion. Chronic—impaired thinking/memory, weight gain/loss. Habituation & physical dependence ® w/drawal syndrome. Abrupt discontinuation ® risk for convulsion (less risk than w/newer BZDs). Metabolism. ¯ in elderly and by cimetidine. Overdose ® serious resp. depression (rarely fatal w/support). ALL BZDs—Use caution w/ age, pregnancy, EtOH/subst. abuse, depression, driving/dangerous machinery, use of other CNS depressants, narcolepsy, hypersensitivity, chronic use > 1 wk- 1 month (except for epilepsy). Psych & phys dependence.
Utility: Anxiety, insomnia, alcohol w/drawal. Sedation—all BZDs are DOCs for sedation.
Special Features: Older BZD (longer t½, less potency).