Effexor is an antidepressant medication approved by the FDA for the treatment of major depression and anxiety. The generic drug name of effexor is venlafaxine. It works in the brain by inhibiting the reuptake of both serotonin and norepinephrine from the fluid in the space around the nerve endings. Of all of the antidepressants Effexor is among the most well known to cause a withdrawal syndrome that can vary from mild to quite severe. This is why effexor withdrawal is so important to learn about. The most common Effexor side effects or symptoms of abrupt discontinuation of Effexor include a very odd sensation that could be described at dizziness, electric shock like feelings, and brain freeze. Some patients simply feel a mild annoying dizziness. Others describe a feeling like their brain does not move as quickly as their head moves when they turn their head. Yet others describe shock like symptoms in the head shoulders and arms most often. Terms like brain freeze, zaps, shocks, and zombie-like have been used to describe the Effexor withdrawal symptom complex. The severity of these symptoms may depend on several variables like the dose of Effexor a patient has been using, how quickly they stop the medication, what other medications they have been or continue to use, and the individual variation from person to person as to how their body responds to stopping Effexor.
Fortunately most patients on stopping Effexor have mild or no withdrawal symptoms. Effexor withdrawal symptoms can be minimized by slowly tapering and discontinuing the medication. Unless there is a pressing reason to discontinue Effexor quickly most experts recommend a slow taper down in Effexor dosage to reduce the severity and likelihood of Effexor withdrawal. If you get Effexor withdrawal symptoms during a taper of Effexor going back up to the last dose without symptoms and resuming the taper more slowly is usually helpful. Another technique used by some physicians is to use Prozac, usually as generic fluoxetine, to avoid the SSRI discontinuation syndrome. Switching from moderate dose Effexor onto fluoxetine seldom leads to Effexor withdrawal symptoms. Then a person can taper off fluoxetine usually without discontinuation symptoms more easily. This seems to be because of the very long serum half-life of fluoxetine, estimated at up to 50 hours in some patients.
It is felt that the likelihood of SSRI discontinuation syndrome from stopping the meds is more likely in the shorter half-life medications. Effexor half-life is only about 5 hours, making it predictable that it is a medication with a higher risk of withdrawal symptoms. The serum half life of a medication is the amount of time it takes for the body to rid itself of 50% of the drug in the bloodstream. Venlafaxine is cleared from the bloodstream moderately quickly, with a serum half-life of about 5 hours. This means that about 87% of a single oral dose is recovered from the urine within 48 hours, mostly as metabolites changed by liver metabolism. This is much shorter than the serum half-life of many of the SSRIs. Fluoxetine, brand name Prozac, is a very long half-life SSRI and withdrawal symptoms are unusual. Paroxetine, brand name Paxil, is a very short half-life SSRI and withdrawal symptoms are very common.
Effexor for some reason seems to have an incidence of withdrawal symptoms, and severity of withdrawal symptoms, that is more severe than would be expected from its moderate serum half-life. The reason for this is unclear, but it is postulated to be related to the reuptake inhibition of both serotonin and norepinephrine as opposed to the primarily serotonin reuptake inhibition of most of the other SSRIs. This dual receptor inhibition seems to allow Effexor to be effective as an antidepressant for many patients who fail to respond to single reuptake inhibition drugs, but the dual reuptake inhibition may be also in part to blame for the higher incidence and severity of Effexor withdrawal symptoms.
The reasons for stopping Effexor can be multiple. They can include lack of efficacy, when the Effexor is just not effective in treatment of the depression of a patient, and Effexor side effects. Some of the more common Effexor side effects that may prompt a patient to want to get off Effexor or lead a physician to recommend stopping Effexor include weight gain, sexual dysfunction including ejaculatory dysfunction in men and anorgasmia in women, sweating, insomnia, nausea, somnolence, dizziness, dry mouth, worsening anxiety and vomiting. Strange but well documented Effexor side effects include yawning, urinary retention and parasthesias. Other patients simply have had a good therapeutic response to Effexor and it is time to stop the use of the antidepressant. Whatever the reason for stopping Effexor, tapering off the medication and recognizing the Effexor withdrawal symptoms for what they are, an annoying but self-limited issue can be helpful in getting through the Effexor withdrawal period of time.
Probably the most important thing to know about effexor withdrawal symptoms is that they are self-limiting. This means that they will resolve on their own in time. Unfortunately this time may be more than a few days in a modest percentage of patients, and some patients have complained of very long duration of withdrawal symptoms. If you experience Effexor withdrawal symptoms consult your prescribing physician for help in managing this disconcerting and sometimes difficult syndrome. Know that you are not alone, and that this is not something strange about you. It is a common and well known and described condition.