Amoxicillin: Increased incidence of allergic skin reactions w/ concomitant use of allopurinol. Augpac
Coumarin or indandione-derivative anticoagulants; heparin; NSAIDs especially, aspirin; other platelet aggregation inhibitors or thrombolytic agents. May decrease efficacy of oestrogen-containing OCs. Augpac Injection
Prolonged bleeding time & prothrombin time in patients on anti-coagulation therapy eg, warfarin. May reduce the efficacy of OCs.