This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Adrenergic System, Subject name: Pharmacology
Propranolol is useful in all except 
Select and explain. 
A. Atrial flutter, B. Parkinsonian tremor, C. Thyrotoxicosis, D. Hypertrophic cardiomyopathy
B: Parkinsonian tremor
Answer: B: Parkinsonian tremor 
Explanation: Ans. (B) Parkinsonian tremor(Ref: KDT 8th/e p164)Propranolol is useful in the management of tremor due to overdose of sympathomimetic agents (b2 mediated). Metoprolol as well as propranolol are effective in essential or familial tremor (b1 mediated). b -blockers are ineffective in intention tremor and rest (parkinsonian) tremors.