1987 Volume 2 Issue 6 Pages 649-655
Urinary metabolite profile of nilvadipine, a new dihydropyridine calcium antagonist, was examined in 6 healthy male volunteers given the drug in single and repeated oral doses. The drug was given first in a single oral dose of 4 mg, and after washout during three days or more, in 11 repeated oral doses of 4 mg twice a day. Nilvadipine and its 5 metabolites were determined in the urine by capillary column gas chromatography or high performance liquid chromatoqraphy. The unchanged nilvadipine was not detected in the urine after either the single or repeated dosings. In the urine collected during 32 hours after a single dosing, 3-carboxyl pyridine derivative of nilvadipine (M3) was excreted in 58.0% of the given dose and 5-carboxyl pyridine derivative in 3.3%. The excretion of the hydroxyl derivative of isopropyl ester moiety of M3 and the 5-carboxyl derivative of nilvadipine accounted for 2.4 and 1.6% of administered dose, respectively. The profile of the urinary metabolites after repeated dosing was similar to that after single dosing.
