398 Quazepam
imal studies find quazepam to have little influence on blood pressure, heart-
beat, 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 peo-
ple dizzy and sleepy and lowered their ability to function normally. In hu-
mans 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 ani-
mals: restless moving around, easy agitation, convulsions.
Drug interactions.In mice quazepam boostsalcohol’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.”Pharmacotherapy10 (1990):
1–10.
“Quazepam: New Hypnotic.”Medical Letter on Drugs and Therapeutics32 (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 Psychopharmacology7 (1999): 257–65.