fluvoxamine increases plasma concentration of etizolam

Inpharma 1474 - 12 Feb 2005

Fluvoxamine increases plasmaconcentration of etizolam

Coadministration of fluvoxamine increases theplasma concentration of etizolam, report researchersfrom Japan.

In their study, 18 Japanese outpatients withpsychiatric disorders received concomitant fluvoxamine25–200 mg/day at a steady dosage for ≥ 2 weeks, beforeor after monotherapy with etizolam 0.75–3 mg/day.

During coadministration of the drugs, the plasmaconcentration of etizolam was increased by a median of39% in the 12 patients who received etizolam plusfluvoxamine 25 mg/day. In the patients receivingetizolam plus fluvoxamine 50 mg/day (n = 5), theplasma concentration of etizolam increased by a medianof 54.6%. In the one patient who received fluvoxamine200 mg/day, the plasma concentration of etizolamincreased from 1.8 ng/mL/mg during monotherapy to8.9 ng/mL/mg.

The researchers note that "the extent of the druginteractions depended on the dose of fluvoxaminecoadministered", although "wide variations wereobserved".Suzuki Y, et al. Effects of concomitant fluvoxamine on the plasma concentrationof etizolam in Japanese psychiatric patients: wide interindividual variation in thedrug interaction. Therapeutic Drug Monitoring 26: 638-642, No. 6, Dec2004 801000792

1

Inpharma 12 Feb 2005 No. 14741173-8324/10/1474-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved