Answer

Effexor XR (venlafaxine extended release) is associated with tinnitus, or ringing of the ears.

The prescribing information for the drug notes that the reported rate of this side effect is less than or equal to the placebo rate.

However, it does specifically state that tinnitus has been reported more often when the drug is being discontinued:

During marketing of Effexor XR, other SNRIs (Serotonin and Norepinephrine Reuptake Inhibitors), and SSRIs (Selective Serotonin Reuptake Inhibitors), there have been spontaneous reports of adverse events occurring upon discontinuation of these drugs, particularly when abrupt, including the following: dysphoric mood, irritability, agitation, dizziness, sensory disturbances (e.g. paresthesias such as electric shock sensations), anxiety, confusion, headache, lethargy, emotional lability, insomnia, hypomania, tinnitus, and seizures.

There are several studies that have reported on Effexor (venlafaxine) related cases of tinnitus. In most cases, tinnitus was resolved fairly quickly after complete discontinuation, at most within 7 days.

If you are getting a good response from Effexor but are concerned you may need to stop it due to the side effect, one study reported that a change from venlafaxine to desvenlafaxine (Pristiq) improved symptoms:

Because of the positive response to venlafaxine in mood and fatigue, that drug was replaced with desvenlafaxine [Pristiq], a selective serotonin- and norepinephrine-reuptake inhibitor and major active metabolite of venlafaxine. Daily oral therapy with desvenlafaxine succinate 76 mg (equivalent to desvenlafaxine 50) mg was commenced, and the patient reported decreased frequency and duration of tinnitus with nearly complete resolution within seven days of the change.

The potential mechanism behind Effexor causing tinnitus isn't well known. One study theorizes that alterations in neural plasticity or effects on the sympathetic nervous system from Effexor could be the cause.

All sources that discuss Effexor induced tinnitus recommend to slowly taper your dose down if discontinuing, as this appears to lessen the severity or prevent it from occurring altogether.

If tinnitus does occur and is uncomfortable or intolerable, resuming a previously well tolerated dose of Effexor may be considered, followed by a more gradual reduction. Nevertheless, data suggests that it should go away within a few days.

In your situation, Effexor may be the cause of the ringing in the ears or there may be other factors. Be sure to discuss what you are experiencing with your doctor.


Summary

Effexor XR (venlafaxine) is associated with tinnitus, or ringing of the ears. It appears to be relatively uncommon, but has a higher incidence rate in those stopping the medication. Symptoms are reported to go away within a few days of discontinuation.


References
  1. Effexor XR Prescribing Information. AccessFDA
  2. Venlafaxine-associated tinnitus. PubMed
  3. Pathophysiology of tinnitus. PubMed