NBRC Pharmacology Practice Exam

Physostigmine, also known as Antilirium, primarily functions as a reversible inhibitor of the enzyme acetylcholinesterase. This inhibition leads to an increase in acetylcholine levels at the neuromuscular junctions and within the central nervous system. While its most recognized use is in treating anticholinergic toxicity and certain types of glaucoma, its role in enhancing respiratory function stems from stimulating cholinergic pathways. Increased acetylcholine can enhance respiratory drive, making it beneficial for patients with conditions characterized by reduced respiratory function.

The other options do not align with physostigmine's primary function. While it may have some secondary effects that could indirectly influence mood or lead to changes in blood pressure and pain perception, these are not its main clinical applications or mechanisms of action. Its specific focus remains on increasing cholinergic activity, which plays a vital role in respiratory drive, especially in situations where the respiratory system is depressed due to anticholinergic drug toxicity.