Venlafaxine is sold under the brand name "Effexor".
Venlafaxine was the first of the non-tricyclic antidepressants able to increase both serotonin and norepinephrine function. It is FDA approved for Major Depression, Generalized Anxiety Disorder, and Social Phobia. The immediate release tablet is now generic but the sustained release venlafaxine XR is not.
Venlafaxine reversibly blocks the recycling of serotonin and, at higher doses, norepinephrine from outside the nerve to inside the nerve. This increase in serotonin and norepinephrine in the gap between nerves in the central nervous system (the synapse) leads to alterations in serotonin and norepinephrine function that have been associated with improvements in depression and anxiety disorders.
Each of these serotonin/norepinephrine reuptake inhibitors (SNRIs for short) has its own personality, if you will. Venlafaxine seems to cause nausea more often than many other antidepressants when starting it. After the initial nausea subsides it tends to be a well tolerated antidepressant with possibly increased robustness of action for some patients who suffer from more serious depressions.
Venlafaxine is processed for elimination from the body (“metabolized”) in the liver to a compound called O-desmethylvenlafaxine that is in clinical trials for licensure as an independent antidepressant. The half life of venlafaxine is only about 4 hours and of desmethylvenlafaxine about 12 hours. When the medication is stopped abruptly (which we do not recommend) significant withdrawal symptoms can occur (that are time limited).
Possible adverse effects can include weight gain, increased blood pressure, nausea, insomnia, agitation, diarrhea, constipation and others.
Venlafaxine does not effect the rate of function of liver enzymes and therefore dose adjustments are not necessary when combined with most other medications.
Venlafaxine carries a warning from the FDA, along with the other SSRIs, against neonatal pulmonary hypertension in neonates exposed to escitalopram in the final trimester of pregnancy.
All antidepressants have a warning from the FDA against new onset suicidal “thoughts and behaviors”. There is no evidence children taking antidepressants are suiciding; quite otherwise, there is very good evidence that children treated for depression suicide less often than children who are depressed who are not treated with antidepressants.
If you miss a dose of venlafaxine do not add it to your next dose. It is important to take venlafaxine regularly as prescribed.
