Venlafaxine (brand name Effexor) is a selective serotonin and norepinephrine reuptake inhibitor (SSNRIs) antidepressant.1 It is used as an off-label ( treatment for fibromyalgia.2 Its mechanism of action is still not fully understood, but it is thought that it affects positively the communication between nerve cells in the central nervous system and/or restores chemical balance in the brain.


Venlafaxine studies

There were no long-term efficacy, tolerability and safety studies regarding the concomitant use of pregabalin, one of the three FDA-approved fibromyalgia therapies, with antidepressant medications such as amitriptyline, venlafaxine or paroxetine, until researchers at Mansoura University (Egypt) hypothesized that the combined use of pregabalinand paroxetine would be associated with comparable Somatic Symptoms Scale-8 (SSS-8) and higher tolerability than amitriptyline or venlafaxine ( (NCT02451475). In fact, results revealed that paroxetine and pregabalin treatment resulted in lower scores in the SSS-8 and depression scale. They also showed that paroxetine and pregabalin resulted in improved tolerability to medication, sleep quality, mood and life satisfaction, and less incidences of high blood pressure and dry mouth.

Nevertheless, and considering its off-label use, doctors may find benefits with venlafaxine for some people with fibromyalgia, as the key to fibromyalgia treatment is to find relief from the pain, fatigue and other symptoms, balancing side effects with efficacy.

Other details

Venlafaxine is taken orally, two or three times a day. It is usually started on a lower dose then gradually increased. It may take 1 to 4 weeks or longer before its effects are effective. This drug may also give withdrawal symptoms, so it should not be suddenly stopped.3

Common venlafaxine side effects may include vision changes, nausea, vomiting and diarrhea, changes in appetite or weight, dry mouth and yawning, dizziness, headache, anxiety and nervousness, fast heartbeats, tremors or shaking, sleep problems, strange dream and tiredness, increased sweating and/or decreased sex drive, impotence and difficulty having an orgasm.1

Venlafaxin is an antidepressant, and, as well as with other antidepressants, it may increase the risk of suicidal thinking and behavior.


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