The antinociceptive effect of zolpidem and zopiclone in mice

Chaim G. Pick, Yakov Chernes, Tova Rigai, Kenner C. Rice, Shaul Schreiber

Research output: Contribution to journalArticlepeer-review


Zolpidem and zopiclone are two of a newer hypno-sedative class of drugs, the "Z compounds". Their use for the treatment of short-term insomnia has been expanding constantly during the last two decades. The "Z compounds" are considered to cause less significant rebound insomnia or tolerance than the conventional hypnotic benzodiazepines. Their possible antinociceptive effect and interaction with the opioid system has not been studied yet. Our results demonstrate a significant difference between the antinociceptive properties of zopiclone and zolpidem when injected s.c. in the hotplate analgesic assay in mice. Zopiclone induced a weak, dose-dependent antinociceptive effect, antagonized only by the α2-adrenergic receptor antagonist yohimbine. Zolpidem induced a weak, biphasic dose-dependent antinociceptive effect, antagonized primarily by the non-selective opioid antagonist naloxone and by yohimbine. The weak antinociceptive effect of both drugs, evident only at very high doses (far beyond those used clinically to induce sleep), implies no clinical use for zopiclone or zolpidem in the management of pain. However, the possible interaction of zolpidem with the opioid system should be further investigated (in behavioral models, which do not overlap with the acute-pain antinociception model we used), both for possible side effects in special populations (i.e. elderly) and for possible drug-drug interactions, in order to minimize possible hazards and maximize clinical beneficial effects of its use for sleep.

Original languageEnglish
Pages (from-to)417-423
Number of pages7
JournalPharmacology Biochemistry and Behavior
Issue number3
StatePublished - Jul 2005


  • Antinociception
  • Drugs interaction
  • Hotplate
  • Mice
  • Opioids
  • Zolpidem
  • Zopiclone


Dive into the research topics of 'The antinociceptive effect of zolpidem and zopiclone in mice'. Together they form a unique fingerprint.

Cite this