The effect of ibuprofen on the excretion of steroid metabolites.

An inexpensive gas chromatographic method is described that allows simultaneous measurement in urine of androsterone (A), aetiocholanolone (E), 11-hydroxyandrosterone (11-OA), 11-hydroxyaetiocholanolone (11-OE), pregnanediol (PD), pregnanetriol (PT), tetrahydrocortisone (THE) and tetrahydrocortisol (THF). Dehydroepiandrosterone was also resolved by the column. Ibuprofen was administered to five healthy normal males at a dose used therapeutically in rheumatoid arthritis (RA). The above urinary steroids were measured weekly during a control period, during a four week period of drug treatment and for four weeks after drug treatment had ceased. The excretion of A fell to a mean of 63% of the control value (p less than 0.02) and returned to the control value within two weeks. 11-OA, which showed a greater variability than A, fell to the same extent (p less than 0.1). No other steroid measured showed a change that could be related to the drug. This relatively limited effect of ibuprofen on steroid metabolism makes it a suitable drug for maintaining patients with RA during studies of their steroid metabolism.