Pharmacokinetic and clinical studies of carprofen in gout.

Carprofen, a carbazole derivative, has been found to be highly potent as anti-inflammatory agent. After a single dose of 100 mg, plasma caprofen peaked in 1 to 2 hours, and t 1/2 was estimated to be 4.4 +/- 1.4 hours, based on a monoexponential fit of the data. Cumulative urinary excretion of total carprofen in 24 hours was almost 30% of the dose, chiefly as glucuronide conjugate. With simultaneous administration of carprofen and probenecid, peak plasma carprofen doubled. The t 1/2 was somewhat prolonged, and urinary excretion was significantly reduced. The t 1/2 of probenecid was not changed, and probenecid uricosuria was unaffected. Carprofen was found to be quite effective for acute gouty arthritis. The drug was well tolerated. Some mild diarrhea developed in one of the 14 patients. No other side effects were observed. The efficacy of carprofen for acute gouty arthritis deserves further trial.