Pharmacokinetics of fluocortolone in long term therapy of patients with rheumatic and hematologic diseases

: The pharmacokinetics of fluocortolone (Ultralan oral) and its effect on plasma cortisol levels were investigated during long-term treatment of patients with rheumatic and haematological diseases with different doses of fluocortolone. Fluocortolone was administered in the morning and plasma levels of fluocortolone and cortisol were measured in samples obtained 1.5, 3, 4, and 5 h p. adm. by means of specific radioimmunoassays. Maximum concentrations of fluocortolone in plasma (Cmax) and areas under the fluocortolone plasma level curves (AUC) increased linearly with the dose. The peak time (tmax = 2.04 +/- 0.85 h) and the plasma half-life (t1/2 = 1.53 +/- 0.52 h) were independent of the dose administered. Cortisol suppression as indicated by morning cortisol levels below 50 ng/ml plasma was not observed with doses below 10 mg/d.