Excretion balance and urinary metabolic pattern of [3H]cabergoline in man

After oral administration of [3H]cabergoline to man at a single nominal dose of 0.6 mg/subject radioactivity is mainly eliminated by the faecal route (72% of the dose after 10 days). Urine contains 18% of the dose after the same period. The unchanged drug and metabolites present in urine were identified by comparison with reference compounds and quantified by radio-TLC analysis. Cabergoline is extensively metabolized. Unchanged drug in 0-24 h urine represents less than 14% of urinary radioactivity, reaching 20% in 0-96 h urine. The acid derivative FCE 21589 is the main metabolite, amounting to 38% and 30% of the urinary radioactivity in 0-24 h and 0-96 h urine, respectively. The amide derivative FCE 21590 appears to be present in only a small amount, accounting for no more than 4% of the urinary radioactivity in the urine of the first 24 hours after administration and increasing to about 8% in the 0-96 h urine.