Which of the following is the longest acting oral anticoagulant -

Ans. is 'a' i.e., Bishydroxycoumarin o Bishydroxycoumarin (Dicumarol) is the longest acting oral anticoagulant.o Ethylbiscoumacetate is the shortest acting anticoagulant.Pharmacokinetic and adverse effect profile of orla anticoagulantsDrugt 1/2 (hour)Duration of action (days)Dose (mg)Adverse side effects (other than bleeding)LoadingMaintenance*1. Bishydeoxycoumarin25-100(dose dependent)4-7200 for 2 days50-100Frequent g.i.t disturbances2. Warfarin sod.36-483-65-102-10EAlopecia, dermatitis, diarrhoea3. Acenocoumarol (Nicoumalone)18-242-38-122-8Oral ulceration, g.i.t. disturbances, dermatitis, urticaria, alopecia4. Ethylbiscoumacetate21-3900300-600Alopecia, bad taste5. Phenindione51-320050-100Orange urine, rashes, fever, leukopenia, hepatitis, nephro-pathy, agranulocytosis* Daily maintenance dose : to be adjusted by measurement of prothrombin time (INR).To be taken in a single dose at the same hour (usually bed time) each day.