NUR 603 Pharm Practice questions Exam Questions with Complete Solutions (100% Correct)

Botulinum toxin blocks the release of acetylcholine from cholinergic nerve terminals. Which is a possible effect of botulinum toxin? A. Skeletal Muscle paralysis B. Improvement of myasthenia gravis symptoms C. Increased salivation D. Reduced heart rate Correct Answer A. Acetylcholine released by cholinergic neurons acts on nicotinic receptors in the skeletal muscle cells to cause contraction. Therefore, blockade of ACh release causes skeletal muscle paralysis. Myasthenia gravis is an autoimmune diseases where antibodies are produced against nicotinic receptors. A reduction in ACH release therefore worsens (not improves) the symptoms of this condition. Reduction in ACh release by botulinum toxin causes reduction in secretions including saliva (not increase in salivation ), causing dry mouth and an increase (not reduction ) in heart rate cut to reduce vagal activity. A patient develops urinary retention after an abdominal surgery. Urinary obstruction was ruled out in this patient. Which strategy would be helpful in promoting urination? A. Activating nicotinic receptors B. Inhibiting the release of acetylcholine C. Inhibiting cholinesterase enzyme D. Blocking muscarinic receptors Correct Answer C. Inhibiting cholinesterase enzyme Activation of muscarinic receptors in the detrusor muscle of the urinary bladder can promote urination in patients where the tone of detrusor muscle is low. Inhibiting cholinesterase enzyme increases the levels of acetylcholine, and acetylcholine can increase the tone of the detrusor muscle. There are no nicotinic receptors in the detrusor muscle; therefore, activation of nicotinic receptors is not helpful. Inhibiting the release of acetylcholine or blocking muscarinic receptors worsens urinary retention. Which of the following drugs could theoretically improve asthma symptoms? A. Bethanechol B. Pilocarpine C. Pyridostigmine D. Atropine Correct Answer D. Muscarinic agonists and drugs that increase acetylcholine levels cause constriction of bronchial smooth muscles and could exacerbate asthma symptoms. Bethanechol and pilocarpine are muscarinic agonists, and pyrodstigmine is a cholinesterase inhibitor that increases levels of acetylcholine. Atropine is a muscarinic antagonists and therefore does not exacerbate asthma. theoretically, it should relieve symptoms of asthma (not used clinically for this purpose).