Pharmacokinetics of phenprocoumon in man investigated using a gas chromatographic method of drug analysis

A gas chromatographic method for the determination of phenprocoumon (Marcumar) in serum and urine is described, which facilitates accurate values down to 0.5 mug phenprocoumon/ml serum. After the i.v. administration of 20 mg phenprocoumon in a single dose to 4 healthy volunteers the following pharmacokinetic data were obtained: After the initial fast decrease (phase 1) of the serum level of phenprocoumon, probably due to the distribution into the different compartments is followed by a subsequent slower fall (phase 2) which occurs with a serum half-life of 157 h. The apparent distribution volume was 6.51. Analysis of the urine demonstrated that 90% of the excreted phenprocoumon detected was in the glucuronide form.