Action and Interaction of Sulfinpyrazone in Anticoagulated Patients

For 8 weeks 29 anticoagulated patients with elevated serum uric acid levels were controlled with 14 days intervals. From week 3 till the end of 6 they received 600 mg sulfinpyrazone p. d. Because of excellent compliance the uric acid decreased from 7.0±0.2 mg% to 3.7±0.2 and raised to 7.1±0.3 (x±x) after omitting the drug. In contrary to this collagen-induced aggregation (5ug/ml, Vmax = ΔE/min.) decreased during the first 14 days of therapy from 0.388±0.048 to 0.228±0.045 (p<0.02) and reached 0.166±0.031 (p<0.01) at the end of the therapy, but with O.269±0.040 did not return to the starting point two weeks after stopping the drug. The increasing effect of therapy and the long lasting effect point to an active metabolite of sulfinpyrazone, which la slowly eliminated. The interaction of sulfinpyrazone with phenproeoumon consisted in a di - placement of the anticoagulant from protein-binding sites, resulting in a fall of the Thrombotest value from 11.2% to 9.0% (p<0,0l). During sulfinpyrazone therapy the GGT increased significantly, indicating an induction of drug metabolizing enzymes in the liver, which had to be counteracted with a higher phenproeoumon dosis for therapeutic anticoagulation.