Which of the following is a potential side effect of medications that increase cardiac contraction strength?

Medications that increase cardiac contraction strength, often referred to as positive inotropic agents, primarily affect the heart muscle. One of the potential side effects associated with these medications is an increased vagal stimulation, which can lead to an increased gag reflex. This occurs because the stimulation of the heart can indirectly influence the autonomic nervous system, affecting the gag reflex and potentially causing episodes of gagging or a heightened sensitivity to gagging stimuli.

The other choices, such as constipation, dry mouth, and drowsiness, are not typically associated with the mechanism of action of inotropic agents. These side effects are more commonly linked to other drug classes, such as anticholinergics or certain sedatives, which do not primarily influence cardiac contraction. Understanding the specific side effects of different drug classes is essential in pharmacology, especially in managing and predicting patient outcomes.