Metadoxine may increase the peripheral decarboxylation of levodopa, decreasing its efficacy.
Incompatibilities: With iron salts, alkaline solutions, oxidant solutions.
Additive effect with sulphonylurea. Glycaemic control may be affected by diuretics, corticosteroids, phenothiazines, thyroid products, oestrogens, oral contraceptives, phenytoin, nicotinic acid. Sympathomimetics, calcium channel blockers, chlorpromazine and isoniazid. Metformin effects may be increased by ACE inhibitors, disopyramide, MAOIs. Cimetidine may increase the serum levels of metformin. Concurrent use with contrast agents may increase the risk of metformin-induced lactic acidosis. May decrease the anticoagulant effect of phenprocoumon, therefore routine anticoagulant monitoring is recommended.
Potentially Fatal: Lactic acidosis with alcohol. Thrombocytopenia has been reported with Ketotifen.