<prompt> Levodopa is contraindicated in:-Alzheimers diseaseMultiple sclerosisGlaucomaParkinsonism  <response>: Levo-dopa may cause mydriasis, so it is contraindicated in angle closure glaucoma. Vitamin complexes containing pyridoxine decrease the effectiveness of levo-dopa pyridoxine is a cofactor of dopa decarboxylase and increases the formation of dopamine in the periphery. This results in decrease in l-dopas central penetration. Abrupt withdrawal of levodopa may precipitate neuroleptic malignant syndrome. Levo-dopa should be given carefully in patients with active peptic ulcer increased risk of bleeding and malignant melanoma levo-dopa is a precursor of melanin. 