442 Zolpidem
distance troop transport the U.S. Army found that zolpidem worked for pro-
moting sleep but had no advantage over triazolam. Another U.S. Army
experiment tested human performance during at least 38 hours of continual
wakefulness, with ambiguous results about whether short naps induced by
zolpidem would be useful in combat circumstances. French researchers found
the drug to be useful for improving quality of sleep in low air pressures found
at high altitude (4,000 meters or 13,123 feet) while producing no breathing
difficulty, a finding relevant not only to mountaineers but to aviators and
astronauts.
Many insomnia medicines produce a rebound effect, meaning that the in-
somnia comes back worse than ever for a few days after people stop taking
the medication. Rebound is seldom observed with zolpidem, however. An
experiment with the drug produced temporary improvement in Parkinson’s
disease symptoms, and zolpidem has helped clear up catatonia. A case report
tells of the drug being given to treat anorexia nervosa, a condition in which
thin people do not eat much because they imagine they are overweight, but
results were unsatisfactory.
Animal experiments show that various chemicals related to zolpidem re-
lieve pain, reduce inflammation and body temperature, and protect against
gastric ulcers. Chemically these substances differ from barbiturates and ben-
zodiazepines, but have effects similar to them and operate in some ways sim-
ilar to benzodiazepines. Monkeys responded in ways indicating that zolpidem
shares similarities with benzodiazepines but few or none with barbiturates.
Despite those resemblances to benzodiazepines, rats trained to distinguish dif-
ferences in drug effects acted as if zolpidem was unlike the benzodiazepine
chlordiazepoxide. Various other differences have been documented. To take
one example,caffeinetypically counteracts some benzodiazepine actions, but
counteraction does not necessarily happen when caffeine is administered with
zolpidem. In animal experimentation chemicals related to zolpidem can pro-
duce sedation at doses low enough to avoid unwanted effects that occur with
benzodiazepine sedation. Substances like zolpidem are generally believed to
accomplish some of the same therapeutic actions as benzodiazepines, with less
abuse potential.
Drawbacks.Caution is recommended if a depressed person takes zolpidem,
as the drug can deepen despondency and even promote suicidal thinking. Less
serious occasional unwanted effects include dry mouth, headache, hiccups,
nausea, and diarrhea. Hallucinations and other psychotic reactions (ranging
from delirium to euphoria) are even less common but documented nonethe-
less.
Abuse factors.Drug abusers report mental pleasure from zolpidem and say
that higher doses feel similar todiazepam. Human experience indicates that
tolerance does not occur with zolpidem, although two or three disputed case
reports exist. Typically, animals who have been dosed with zolpidem for
months show no tolerance, dependence, or withdrawal symptoms. Diligent
experimenters, however, have been able to produce dependence and with-
drawal in baboons. Those effects have seldom been observed in humans, but
case reports exist. Someone took 30 to 40 times the normal daily medical
dosage on his own accord for months and developed dependence. This per-