1. Which of the following anti-Parkinson drug may cause peripheral vasospasm? a) Ropinirole b) Amantadine c) Bromocriptine d) Carbidopa Answer: Bromocriptine Explanation: Bromocriptine is a dopamine receptors agonist that may cause peripheral vasospasm. It is contraindicated in patients with peripheral vascular disease. Ropinirole directly stimulate the dopamine receptors but it doesn’t cause vasospasm. Amantadine and Carbidopa do not act directly act on dopamine receptors. 2. Lithium should be stopped how many days before surgery a) 1 b) 2 c) 3 d) 4 Answer: 2 days Explanation: Lithium is used to treat bipolar affective disorders. It may potentiate the effect of depolarizing and competitive neuromuscular blocking agents. The clearance of lithium can be reduced and its toxicity increased by factors that cause negative fluid balance, negative sodium balance, and decreased glomerular filtration rate. Lithium should be discontinued 2-3 days before major surgery and resumed when renal function and electrolyte levels are stable. If serum levels are not in a toxic range, renal function is normal, and fluid electrolyte status is stable, lithium can be continued before minor surgery. 3. ATT side effects as hypothyroidism a) INH b) Pyrazinamide c) Ethionamide d) Streptomycin Answer: Ethionamide Explanation: Ethionamide is second-line anti-tuberculosis medication. Ethionamide is administered at a dose of 15–20 mg/kg/day (maximum 1 g/day) once or twice/day. Ethionamide use is most commonly limited by gastrointestinal intolerance. Taking ethionamide at bedtime or with food may improve tolerance. Hypothyroidism is an important adverse event; therefore, thyroidstimulating hormone levels should be measured at baseline and monthly while patients are receiving therapy. Hepatotoxicity can also occur with ethionamide; therefore, baseline liver function tests should be obtained. 4. Methacholine agonist at a) M2 b) M1 c) M4 d) M3 Answer: M2 Explanation: Ganglionic and other neural muscarinic receptors (M1) are apparently involved in CNS transmission. M3 muscarinic receptors on airway smooth muscle mediate broncho-constriction and pre-synaptic M2 muscarinic receptors inhibit acetylcholine release, causing broncho-dilation. Tiotropium, a selective antagonist of M3 receptors has recently been approved for treatment of chronic obstructive pulmonary disease (COPD). One of the advantages tiotropium is that it generally blocks only postsynaptic M3 receptors (that promote broncho-constriction) but does not block pre-synaptic M2 receptors (That cause broncho-dilation). Methacholine acts as M2-selective muscarinic receptor agonist to stimulate the parasympathetic nervous system. It is most commonly used for diagnosing bronchial hyper-reactivity, using the bronchial challenge test.
Posted on: Wed, 08 Oct 2014 12:06:07 +0000
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