Premarketing experience with venlafaxine in patients with concomitant systemic illness is limited.

Caution is advised in administering Venlafaxine Hydrochloride Extended-Release Tablets to patients with diseases or conditions that could affect hemodynamic responses.

Venlafaxine has not been evaluated or used to any appreciable extent in patients with a recent history of myocardial infarction or unstable heart disease. Patients with these diagnoses were systematically excluded from many clinical studies during venlafaxine's premarketing testing. The electrocardiograms were analyzed for 275 patients who received venlafaxine hydrochloride extended-release capsules and 220 patients who received placebo in 8- to 12-week double-blind, placebo-controlled trials in major depressive disorder as well as for 195 patients who received venlafaxine hydrochloride extended-release capsules and 228 patients who received placebo in 12-week double-blind, placebo-controlled trials in Social Anxiety Disorder. The mean change from baseline in corrected QT interval (QTc) for patients treated with venlafaxine hydrochloride extended-release capsules in major depressive disorder studies was increased relative to that for placebo-treated patients (increase of 4.7 msec for venlafaxine hydrochloride extended-release capsules and decrease of 1.9 msec for placebo). The mean change from baseline in QTc for patients treated with venlafaxine hydrochloride extended-release capsules in the Social Anxiety Disorder studies was increased relative to that for placebo-treated patients (increase of 2.8 msec for venlafaxine hydrochloride extended-release capsules and decrease of 2.0 msec for placebo).

In these same trials, the mean change from baseline in heart rate for patients treated with venlafaxine hydrochloride extended-release capsules in the major depressive disorder studies was significantly higher than that for placebo (a mean increase of 4 beats per minute for venlafaxine hydrochloride extended-release capsules and 1 beat per minute for placebo). The mean change from baseline in heart rate for patients treated with venlafaxine hydrochloride extended-release capsules in the Social Anxiety Disorder studies was significantly higher than that for placebo (a mean increase of 5 beats per minute for venlafaxine hydrochloride extended-release capsules and no change for placebo).

In a flexible-dose study, with doses of venlafaxine hydrochloride immediate-release tablets in the range of 200 to 375 mg/day and mean dose greater than 300 mg/day, patients treated with venlafaxine hydrochloride immediate-release tablets had a mean increase in heart rate of 8.5 beats per minute compared with 1.7 beats per minute in the placebo group.

As increases in heart rate were observed, caution should be exercised in patients whose underlying medical conditions might be compromised by increases in heart rate (e.g., patients with hyperthyroidism, heart failure, or recent myocardial infarction).

Evaluation of the electrocardiograms for 769 patients who received venlafaxine hydrochloride immediate-release tablets in 4- to 6-week double-blind, placebo-controlled trials showed that the incidence of trial-emergent conduction abnormalities did not differ from that with placebo.