Pharmacokinetics of canrenone after oral administration of spironolactone and intravenous injection of canrenoate-K in healthy man.

Five healthy male volunteers received canrenoate-K 200 mg (Sincomen pro injectione) by intravenous injection and one week later spironolactone 200 mg (Sincomen-100) orally. Plasma levels and urinary excretion of unchanged canrenone were determined up to 24 h by a specific HPLC method. Following intravenous administration, the maximum plasma level of 2066 +/- 876 ng/ml was found after 29 +/- 15 min and thereafter the concentration declined with a half-life of 3.7 +/- 1.2 h. Total clearance was 4.2 +/- 1.7 ml/min . kg. After oral ingestion, the maximum concentration of 177 +/- 33 ng/ml was observed at 4.4 +/- 0.9 h. The absolute bioavailability of canrenone was 25 +/- 9%. Within 24 h, respectively 0.4 and 0.6 mg, canrenone were excreted by the kidney after intravenous and oral administration. The half-life of elimination was 4.9 +/- 1.8 h (i.v.) and 3.9 +/- 1.2 h (p.o.).