Certified Ophthalmic Medical Technologist (COMT) Practice Exam

Which cholinergic blocking agent should be used cautiously due to its prolonged effect?

1. Atropine sulfate

2. Scopolamine hydrobromide

3. Pilocarpine

4. Phenylephrine

The correct answer is: Atropine sulfate

Atropine sulfate is a cholinergic blocking agent known for its ability to inhibit the action of acetylcholine on muscarinic receptors. This can lead to a variety of pharmacological effects, including increased heart rate and reduced secretion of salivary glands. One of the key characteristics of atropine is its prolonged duration of action. This means that once administered, the effects can last longer than those of other agents, which could lead to potential complications if not carefully monitored. In situations where atropine is used, such as in mydriasis (pupil dilation) or in the management of certain types of bradycardia, its extended effects necessitate caution, especially in populations that may be more sensitive to such changes, such as the elderly or those with certain pre-existing conditions. The longer duration of activity means that clinicians must ensure that the effects are appropriate for the patient's specific needs and monitor for any adverse reactions or over-medication. In contrast, the other options listed have different pharmacological profiles or shorter durations of action, which typically allows for a broader margin of safety regarding their use without the same concern for prolonged effects. This distinction underscores why atropine sulfate is identified specifically as needing careful administration due to its prolonged impact on the