440 Zaleplon
rable to lorazepam’s but shorter in duration. Because of possible memory dif-
ficulty, an individual using zaleplon may want to avoid situations involving
important decisions. Other unwanted effects may include skin rash, muscle
tightness, pain in chest and back, migraine headache, constipation, difficulty
in concentrating, and emotional depression. Euphoria is a less common effect.
Abuse factors.Studies indicate zaleplon has about the same potential for
abuse as benzodiazepine class depressants do. Researchers using volunteers
who had previously abused drugs concluded that zaleplon and triazolam have
the same abuse potential. No tolerance emerged in studies where people took
zaleplon for weeks and months. No dependence developed either, but that
finding is not considered conclusive. In animal studies dependence has oc-
curred, severe enough that some animals died when the drug was cut off.
Researchers conducting a baboon experiment found zaleplon to have about
the same dependence potential as triazolam.
Drug interactions.Alcoholshould be avoided when taking zaleplon. Tests
have demonstrated that zaleplon boosts the effects of alcohol and also boosts
some action of the psychiatric medication thioridazine.
Cancer.Cancer emerged in some mice that received 6 to 49 times the max-
imum human dose of zaleplon for two years, but cancer did not develop in
rats that received 5 to 10 times the maximum human dose. Likewise, labora-
tory tests of the drug’s cancer-causing potential have had mixed results.
Pregnancy.The drug has not caused birth defects in rats and rabbits receiv-
ing almost 50 times the maximum human dose. Rat offspring had impaired
growth, however. The drug passes into maternal milk of rats at levels high
enough to affect offspring; keep in mind, however, that these milk levels result
from doses exceeding the maximum recommended for humans. In humans
the drug passes into milk of nursing mothers; impact on the infants is un-
known but is presumed to be harmless. At its peak the amount of zaleplon
in milk is less than 0.02% (two one-hundredths of one percent) of the mother’s
dose, and that amount declines rapidly an hour after a mother takes zaleplon.
Additional information.Sonata tablets contain FD&C Yellow No. 5 (tartra-
zine), to which some persons seem allergic, particularly if they have an aspirin
sensitivity.
Additional scientific information may be found in:Chagan, L., and L.A. Cicero. “Zaleplon: Possible Advance in the Treatment of Insom-
nia.”P&T: A Peer-Reviewed Journal for Formulary Management24 (1999): 590.
Heydorn, W.E. “Zaleplon—A Review of a Novel Sedative Hypnotic Used in the Treat-
ment of Insomnia.”Expert Opinion on Investigational Drugs9 (2000): 841–58.
Mangano, R.M. “Efficacy and Safety of Zaleplon at Peak Plasma Levels.”International
Journal of Clinical Practice: Supplement79, no. 116 (2001): 9–13.
Rush, C.R., J.M. Frey, and R.R. Griffiths. “Zaleplon and Triazolam in Humans: Acute
Behavioral Effects and Abuse Potential.”Psychopharmacology145 (1999): 39–51.
Troy, S., and M. Darwish. “Maximal Effects and Residual Effects: Zaleplon vs. Zolpi-
dem and Triazolam.”American Society of Hospital Pharmacists Annual Meeting 56
(June 1999): 59.
Troy, S., et al. “Comparison of the Effects of Zaleplon, Zolpidem, and Triazolam on
Memory, Learning, and Psychomotor Performance.”Journal of Clinical Psycho-
pharmacology20 (2000): 328–37.
“Zaleplon for Insomnia.”Medical Letter on Drugs and Therapeutics41 (1999): 93–94.