Pharmacokinetics of high-dose oral and intravenous dexamethasone

Pharmacokinetics of intravenous and oral pulsed high-dose dexamethasone were studied in four patients with pemphigus vulgaris. Doses for dexamethasone were varied from 100 to 300 mg. Serum concentrations were measured by high-performance liquid chromatographic procedure with diode assay detection. Bioavailability was assessed by comparing the areas under the serum concentration-time curves following oral administration with those of intravenous administration. Mean bioavailability of highdose oral dexamethasone was 63.4%. Side-effects were minor and were limited to temporary facial flushing both after oral and intravenous administration. Oral administration of dexamethasone in pemphigus patients showed to be more convenient and cost-reducing than administration by the intravenous route. 47 Tóth GG, Kloosterman Ch, Uges DRA, Jonkman MJ. Pharmacokinetics of high-dose oral and intravenous dexamethasone. Ther Drug Monit 1999;21:532-5.