Vit A: Increased risk of bleeding w/ anticoagulants. Potential additive undesirable effects w/ retinoid (eg, etretinate, isotretinoin, tretinoin). Increased risk of pseudomotor cerebri w/ minocycline. Increased serum levels w/ statins. Vit C: Increased risk of Al toxicity w/ antacids, especially in patients w/ renal insufficiency. May decrease excretion of aspirin. May interfere w/ the alcohol-disulfiram reaction. Decreased fluphenazine plasma level. May accelerate excretion of mexiletine. Increases apparent t
½ of paracetamol. Reduced blood levels w/ OCs containing estrogens. Decreased anticoagulant effect of warfarin. May result in altered excretion of other drugs. Interferes w/ results of lab tests eg, paracetamol, AST, bilirubin, carbamazepine, creatinine, glucose, LDH, stool guaiac, theophylline, & uric acid. Vit E: May have anti-vit K effects; hemorrhage w/ concomitant intake of anticoagulants. May potentiate the effects of antiplatelets & herbs eg, garlic & ginkgo. Zn: Decreases absorption of cephalosporins, quinolones & tetracyclines, bisphosphonates. Risk of additive effects of cholesterol medicines. Inhibits absorption of Cu & Fe.