Are there any interactions between diclofenac and diazepam?

Fråga: Are there any interactions between diclofenac and diazepam?

Sammanfattning: Diazepam has been shown to increase the serum levels of diclofenac in a single-dose study in healthy volunteers.

Svar: This question has previously been answered in Drugline in 1994 (1). At that time there was no information in the literature supporting an interaction between diclofenac and diazepam. A study has since been published concerning the time-dependant influence of diazepam on the pharmacokinetics of diclofenac (2). Eight healthy volunteers were given diclofenac alone or in combination with diazepam at ten o´clock in the morning and in the night. The peak serum levels of diclofenac were 45 per cent higher in the morning than in the night and a significant rise in the mean peak level was also seen when diclofenac was given together with diazepam. This interaction was more pronounced in the night than in the morning (112 versus 68 percent increase). The authors discuss that diazepam may have time-dependent effects on gastrointestinal motility. The explanation could possibly be cytochrome specific interaction on the enzyme responsible for metabolism of diclofenac. 1 Drugline nr 11556 (year 1994) 2 Mahener VN, Rambhau D, Rao BR, Rao VVS, Venkateshwarlu G: Time-dependenent influence of diazepam on the pharmacokinetics of orally administered diclofenac sodium in human subjects. Clin Drug Invest 1995; 10: 296-301