A PHARMACOKINETIC INTERACTION BETWEEN ROXITHROMYCIN AND MIDAZOLAM

The interaction between roxithromycin and midazolam was investigated i n a double-blind, randomised crossover study of two phases. Ten health y volunteers were given roxithromycin (300 mg) or placebo once daily f or 6 days. On the sixth day they ingested 15 mg midazolam. Plasma samp les were collected and psychomotor performance measured for 17 h. Roxi thromycin administration significantly increased the area under the pl asma midazolam concentration-time curve from 8.3 to 12.2 mu g.ml(-1).m in and the elimination half-lives from 1.7 to 2.2 h. In psychomotor pe rformance only minor differences were seen between the treatments in o ne of the measured psychomotor parameters. Thus, in contrast to the st rong interaction between erythromycin and midazolam, the interaction b etween roxithromycin and midazolam appears less likely to be clinicall y significant.