Review of Z-drug toxicology

February 20, 2013, 12:27 am


The Clinical and Forensic Toxicology of Z-drugs. Gunja N. J Med Toxicol 2013 Feb 13 [Epub ahead of print]


This well done article is the most comprehensive discussion I’ve seen about the pharmacology and toxicology of the so-called Z-drugs: zolpidem (Ambien), zopiclone (Imovane), and zaleplon (Sonata). It also touches on eszopiclone (Lunesta), the active enantiomer of zopiclone.

All these drugs are non-benzodiazepine sedative-hypnotic agents that act as agonists at the GABAA receptor. These drugs tend to have relatively short durations, making them effective at inducing but not necessarily maintaining sleep. Zopiclone is the longest acting. Zaleplon is described as ultra-short acting, with a half life of about 1 hour.

These drugs are generally well tolerated. Elderly patients are more susceptible to adverse effects, which include residual sedation, imbalance and falls, parasomnias, bizarre behavior, hallucinations, and psychosis. In January 2013, the FDA advised lowering standard zolpidem doses — especially in women and those taking extended-release products — to minimize the chance of next-day drowsiness and mental clouding. (Much praise to the author and editors for including this late-breaking development in both the article and the references.)

Treatment of Z-drug overdose is generally supportive. Activated charcoal should be avoided because sedation may result in an unprotected airway. Flumazenil will reverse the sedative effects of all Z-drugs, but should be used with caution — if at all — in cases of multidrug overdose and/or unclear history.

Important note: Z-drugs should not be confused with ZDogg.


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