<prompt> Which of the following is the longest acting oral anticoagulant -BishydroxycoumarinWarfarinAcenocoumarolPhenindione  <response>: 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 12 hourDuration of action daysDose mgAdverse side effects other than bleedingLoadingMaintenance1. Bishydeoxycoumarin25-100dose dependent4-7200 for 2 days50-100Frequent g.i.t disturbances2. Warfarin sod.36-483-65-102-10EAlopecia, dermatitis, diarrhoea3. Acenocoumarol Nicoumalone18-242-38-122-8Oral 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. 