The nurse monitors a client on venlafaxine. Which finding requires immediate intervention?

Venlafaxine is a serotonin-norepinephrine reuptake inhibitor (SNRI) used to treat depression, anxiety disorders, and other conditions. A well-documented and clinically significant adverse effect of venlafaxine is dose-dependent hypertension. The increase in blood pressure from 118/70 mmHg to 154/92 mmHg represents a meaningful elevation into the hypertensive range and requires immediate nursing intervention. This increase is attributable to venlafaxine's norepinephrine reuptake inhibition, which can increase sympathetic tone and raise blood pressure. Sustained hypertension increases the risk of stroke, myocardial infarction, and other cardiovascular events, making it a priority concern. The other findings listed are common, expected, and generally benign side effects of venlafaxine that do not require immediate intervention. Mild nausea is a frequently reported early side effect that typically resolves within the first few weeks of therapy. Insomnia is also a known side effect of SNRIs due to their stimulating noradrenergic effects and is usually managed by adjusting the dosing schedule. Dry mouth is a typical anticholinergic-adjacent effect seen with venlafaxine. While all side effects should be documented and monitored, none are immediately dangerous, in contrast to the blood pressure elevation, which requires prompt notification of the prescriber and possible dose reduction or medication change.