Format

Send to

Choose Destination
Clin Pharmacol Ther. 1999 Jul;66(1):33-9.

Effect of saquinavir on the pharmacokinetics and pharmacodynamics of oral and intravenous midazolam.

Author information

1
Department of Anesthesia, University of Helsinki, Finland.

Abstract

OBJECTIVE:

To assess the effect of human immunodeficiency virus protease inhibitor saquinavir on the pharmacokinetics and pharmacodynamics of oral and intravenous midazolam.

METHODS:

In a double-blind, randomized, two-phase crossover study, 12 healthy volunteers (six men and six women; age range, 21 to 32 years) received oral doses of either 1200 mg saquinavir (Fortovase soft-gel capsule formulation) or placebo three times a day for 5 days. On day 3, six subjects were given 7.5 mg oral midazolam and the other six subjects received 0.05 mg/kg intravenous midazolam. On day 5, the subjects who had received oral midazolam on day 3 received intravenously midazolam and vice versa. Plasma concentrations of midazolam, alpha-hydroxymidazolam, and saquinavir were determined for 18 hours after midazolam administration, and midazolam effects were measured up to 7 hours by six psychomotor tests.

RESULTS:

Saquinavir increased the bioavailability of oral midazolam from 41% to 90% (P < .005), the peak midazolam plasma concentration more than twofold, and the area under plasma concentration-time curve more than fivefold (P < .001). During saquinavir treatment, five of the six psychomotor tests revealed impaired skills and increased sedative effects after midazolam ingestion (P < .05). Saquinavir decreased the clearance of intravenous midazolam by 56% (P < .001) and increased its elimination half-life from 4.1 to 9.5 hours (P < .01). After intravenous midazolam, only the subjective feeling of drug effect was increased significantly (P < .05) by saquinavir.

CONCLUSION:

The dose of oral midazolam should be greatly reduced or avoided with saquinavir, but bolus doses of intravenous midazolam can probably be used quite safely. During a prolonged midazolam infusion, an initial dose reduction of 50% followed by careful titration is recommended to counteract the reduced clearance caused by saquinavir.

PMID:
10430107
DOI:
10.1016/S0009-9236(99)70051-2
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center