Reactions 535 - 28 Jan 1995

Diazepam interacts withfluvoxamine

An interaction between diazepam and fluvoxaminereported by investigators from Israel ‘may haveimportant implications’, in their opinion.

Plasma diazepam concentrations were markedlyincreased, the elimination half-life was markedlyprolonged and clearance was reduced when a single10mg dose was given during administration offluvoxamine 50–150 mg/day in 8 volunteers. In addition,the AUC of diazepam was increased by 70–390% whenthe 2 agents were given concomitantly.

Furthermore, concomitant administration ofdiazepam and fluvoxamine resulted in later peakconcentrations of the diazepam metabolite, N-desmethyldiazepam, and significantly increased AUCvalues of this metabolite.

Fluvoxamine is also known to impair the metabolismof other benzodiazepines that are eliminated byoxidation. The investigators suggest that a nonoxidisedbenzodiazepine such as lorazepam may be preferable inpatients who are also receiving fluvoxamine.Perucca E, et al. Inhibition of diazepam metabolism by fluvoxamine: apharmacokinetic study in normal volunteers. Clinical Pharmacology andTherapeutics 56: 471-476, Nov 1994 800333820

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Reactions 28 Jan 1995 No. 5350114-9954/10/0535-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved