NUR 136 Pharmacology in Nursing Education, Drug Classifications and Therapeutic Use Exam with Questions and Answers

It covers key domains which include Autonomic Nervous System Agents, Central Nervous System Agents, Central Nervous System Agents, Cardiovascular Agents, Anti-infectives and Endocrine Agents. Atropine is administered to a patient with symptomatic bradycardia in the emergency unit. Which pharmacologic action best explains its therapeutic effect? a. Stimulates nicotinic receptors at the neuromuscular junction b. Blocks muscarinic receptors at parasympathetic sites in the heart c. Inhibits norepinephrine reuptake in sympathetic nerve endings d. Activates beta-2 adrenergic receptors in bronchial smooth muscle Correct Answer: b Blocks muscarinic receptors at parasympathetic sites in the heart Rationale: Atropine is an anticholinergic drug that competitively blocks muscarinic acetylcholine receptors. In the heart, it inhibits vagal (parasympathetic) influence on the SA node, leading to increased heart rate. This makes it useful in treating symptomatic bradycardia. It does not act on nicotinic receptors, nor does it directly stimulate adrenergic receptors. A patient with myasthenia gravis is prescribed neostigmine. Which therapeutic effect is expected? a. Decreased acetylcholine breakdown leading to improved muscle strength b. Direct stimulation of skeletal muscle nicotinic receptors c. Blockade of dopamine receptors in the central nervous system d. Inhibition of calcium release from the sarcoplasmic reticulum Correct Answer: a Decreased acetylcholine breakdown leading to improved muscle strength Rationale: Neostigmine is an acetylcholinesterase inhibitor. It prevents the breakdown of acetylcholine at the neuromuscular junction, increasing its availability and improving skeletal muscle contraction in conditions like myasthenia gravis. It does not directly stimulate receptors or act on dopamine or calcium release mechanisms.