About pentoxifyllinesa xanthine derivative, phosphodiesterase inhibitor, blood viscosity reducing agent.smechanism of action of pentoxifyllinesthe drug exerts its pharmacological action by improving rheological (flow) properties of blood. it improves blood flow to ischaemic areas by increasing capillary blood flow by improving erythrocyte flexibility and reducing blood viscosity. it inhibits phosphodiesterase enzyme.sindications for pentoxifyllines1.intermittent claudication s2.occlusive arterial diseases of limbs s3.cerebrovascular insufficiency s4.circulatory disorder due to arteriosclerosis s5.trophic disorders s6.acute non haemorrhagic stroke s7.other chronic occlusive vascular disorders sinteractions for pentoxifyllineswarfarin: bleeding and prolonged prothrombin time in patients receiving pentoxifylline with or without anticoagulants or platelet aggregation inhibitors. pt(prothrombin time) should be monitored in patients on warfarin.