This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sedative-Hypnotics and Parkinsonism, Subject name: Pharmacology
Levodopa is contraindicated in:- 
Select and explain. 
A. Alzheimer's disease, B. Multiple sclerosis, C. Glaucoma, D. Parkinsonism
C: Glaucoma
Answer: C: Glaucoma 
Explanation: 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-dopa's 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).