Pregnancy Category X
Uses. Insomnia is one of the main medical conditions treated by this drug, which also has anticonvulsant properties. The compound has been found useful to counteract insomnia actions of some psychiatric medicines. Although one insomnia study showed doses losing some effectiveness over time, patients continued to sleep better for 15 nights after dosage stopped, an improvement not observed when people stop taking some other antiinsomnia drugs. Similar findings have come from other experimentation. Antiinsomnia drugs commonly have "rebound" effects in which insomnia temporarily becomes worse than ever when dosage stops. Little or no rebound is observed with quazepam, perhaps because it is eliminated rather slowly from the body. A study noted that quazepam not only reduced anxiety among insomniacs but that the decline in anxiety continued for 15 days after dosage stopped.
The drug has been tested against other substances used against insomnia: triazolam, temazepam, and flurazepam. In some respects triazolam was six times stronger than quazepam, but researchers judged quazepam as superior to triazolam and temazepam in aiding sleep. In animals quazepam produced brainwave measurements that resembled normal sleep more than flurazepam did. Flurazepam leaves people groggier than quazepam the day after bedtime use. In contrast to flurazepam, quazepam slows mice without making them physically discoordinated. Still another advantage of quazepam is its relative safety; in one experiment a particular dose of flurazepam killed animals, but four times that amount of quazepam left animals apparently unharmed—and still larger doses caused sickness but not death. One group of experimenters was unable to find the LD50 (lethal dose 50) of quazepam. "LD50" is the amount of drug that will kill half the animals receiving it; the researchers could not find a dose producing fatal poisoning in more than 10% of the animals. Other experimenters, however, report success at achieving LD50. An imal studies find quazepam to have little influence on blood pressure, heartbeat, and breathing. A human study found no change in daytime attentiveness or muscular coordination after awakening from a nighttime dose. In one study researchers were surprised to discover improvement in ability to move limbs quickly and precisely the day after taking a normal bedtime dose of quaze-pam.
Drawbacks. Depending on size of doses, people might feel drowsy and slow-moving during the daytime after taking quazepam the night before, but some researchers describe that effect as minor. Various attempts to measure other adverse effects of the drug have found none, but an experiment using a dosage six times stronger than a recommended therapeutic dose made people dizzy and sleepy and lowered their ability to function normally. In humans an impairment of eye movement and eye-hand coordination can be measured, but the practical significance of those deficits is unclear. Animal studies with the drug produce abnormalities in the liver and in male gonads.
Abuse factors. Tolerance and dependence can develop. Sudden stoppage of quazepam after a full year of dosing produces withdrawal symptoms in animals: restless moving around, easy agitation, convulsions.
Drug interactions. In mice quazepam boosts alcohol's effects, but in humans a test of skill in movement found the combination to have the same effect as alcohol plus placebo.
Cancer. Oral dosage in mice and hamsters did not produce cancer.
Pregnancy. Research is scanty about quazepam's potential for causing birth defects, but the drug is considered a producer of fetal malformations. In mice a substantial amount of a quazepam dose passes into a fetus. Human testing has shown that about 0.1% of a quazepam dose (and its metabolites) passes into the milk of nursing mothers.
Additional scientific information may be found in:
Ankier, S.I., and K.L. Goa. "Quazepam: A Preliminary Review of Its Pharmacodynamic and Pharmacokinetic Properties, and Therapeutic Efficacy in Insomnia." Drugs 35 (1988): 42-62.
Kales, A. "Quazepam: Hypnotic Efficacy and Side Effects." Pharmacotherapy 10 (1990): 1-10.
"Quazepam: New Hypnotic." Medical Letter on Drugs and Therapeutics 32 (1990): 39-40. Rush, C.R., and J.A. Ali. "A Follow-up Study of the Acute Behavioral Effects of Benzodiazepine-Receptor Ligands in Humans: Comparison of Quazepam and Triazolam." Experimental and Clinical Psychopharmacology 7 (1999): 257-65.
Continue reading here: Sibutramine
Was this article helpful?