Interactions of some Drugs with Commonly used Oral Anticogulants

The effects of norgestrel , ethinyl estradiol and cholesterolon theanticoagulant effect of warfarin were studied in rabbits. Wararin was given alone for 8 days. Norgestrel;ethinyl estradiol and chlesterol were administered orally daily for one month then warfarin was given daily for8 days. Measurement were done initially and after 2, 4 and 8 days of administration of earfarin.The combination of warfarin and cholesterol and norgestrel produced significant decrease in prothrombin time and clotting time and no change in haematocrit value after two days of warfarin treatment . There was also significant decrease in clotting time only .The results of the individual drugs alone and in combination were discussed.