What is a common side effect of nondepolarizing neuromuscular blockers?

Nondepolarizing neuromuscular blockers, such as rocuronium and vecuronium, are agents that prevent muscle contractions by blocking acetylcholine from binding to nicotinic receptors at the neuromuscular junction. A common side effect of their use is respiratory depression. This occurs because these drugs inhibit the action of the diaphragm and other respiratory muscles, leading to reduced ability to breathe unaided. As neuromuscular blockers induce paralysis, careful monitoring of respiratory function is crucial in clinical settings where these agents are employed, especially during surgical procedures or when used for ventilation support.

The other options do not align with the pharmacological effects of nondepolarizing neuromuscular blockers. Hypertension is typically not a direct side effect associated with these agents, and increased salivation is often more associated with certain types of cholinergic drugs rather than neuromuscular blockers. Severe muscle spasm isn't a commonly noted effect, as these drugs are designed to inhibit muscle activity rather than cause spasms. Understanding the mechanism of action and the resultant effects helps clarify why respiratory depression is an expected outcome during the administration of nondepolarizing neuromuscular blockers.