This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Pharmacology
A patient was started on fluphenazine. After few weeks of treatment, he started developing tremors, rigidity, bradykinesia and excessive salivation. First line of management for this patient is 
Select and explain. 
A. Trihexyphenidyl, B. Pramipexole, C. Amantadine, D. Selegiline
A: Trihexyphenidyl
Answer: A: Trihexyphenidyl 
Explanation: * Fluphenazine - D2 blocker (Anti-psychotic)* This is a case of typical antipsychotic induced parkinsonism.* The only group of drugs effective against "Pharmacological parkinsonism" (Drug induced parkinsonism) are Anti-cholinergic agents* Trihexyphenidyl:# Has high Central: Peripheral anticholinergic actions than atropine# Acts by reducing unbalanced cholinergic activity in striatum of parkinsonism patients# Order of relief of symptoms: Tremors > Rigidity > Hypokinesia# Peripheral actions - responsible for treatment of sialorrhea# Started at low dose and gradually increased