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Effexor (Venlafaxine) Side Effects, Withdrawal and FAQs

The FDA mandated in 2007 that Effexor packaging update a black box label on packaging to warn consumers that this antidepressant drug should not be taken by anyone under the age of 25 years old due to studies that showed the drug caused a five-fold increase in suicidality.

Before embarking on a prescription, whether to treat depression, anxiety, or other conditions, it is highly recommended that a person acquaint themselves as fully as possible with the various side effects and withdrawal effects before electing to begin any drug for treatment.

The antidepressant drug Effexor (venlafaxine) was discontinued sometime estimated to occur after 1997, (data not available) when some trials showed that an extended release version caused less nausea. No other trials or tests besides the nausea test can be found which indicate that the XR version has been proven any more or less safe than the original immediate release version of the drug. (1)

Effexor (venlafaxine) is thought to block certain neurotransmitters in the body, inducing an artificial increase of effect, though the result is temporary. The effect increases in relation to the strength of the dosage. Effexor is classed as an SNRI drug, and has unique characteristics that set it apart from other re-uptake inhibiting antidepressant drugs.

Some antidepressants increase the available amount of serotonin that is active in the body. Serotonin is what influences such things as anxiety, sleep, memory, aggression, learning, mood, appetite, body temperature, and other important functions.  It is an inhibitory agent. Although serotonin is stimulating to certain digestive functions, if is inhibitory to the central nervous system.

Some antidepressants affect the adrenergic receptors, such as adrenaline and norepinephrine. These are excitatory neurotransmitters, which, among other necessary functions, regulates proper blood flow, regulates blood pressure, and stimulates other changes such as those related to “fight or flight” mechanisms.

Some antidepressant drugs can purge and suspend dopamine, which is often referred to as the reward chemical, or the agent which activates the pleasure centers in the body/brain as well as motor function, long term memory, mood and emotion, addiction reinforcement, laughter, and many other responses.

EffexorXR (venlafaxine) is highly unique in that it is one of a very small number of antidepressants in existence that are described as affecting reuptake of all three of these types of neurotransmitters concurrently, especially when taken at higher doses, causing a temporary surge of these agents in the body.  (2)

Special warning letters and health alerts have been issued by the FDA to the makers of Effexor (now EffexorXR) since 2003 covering important health consequences including:

  • risk to pregnancy
  • birth defects and complications after birth
  • increased risk of bone fracture linked to decreased bone mineral density in older populations
  • suicidality in children and young adults
  • suicidality in adults
  • risk for serotonin toxicity (see Serotonin Syndrome below)
  • risk for overdose especially in connection with alcohol or other concurrent medications

We have described some of the important facts in more detail below for educational purposes. If you have additional questions, be sure to ask your care provider or other medical professional for further information so an informed decision can be made about your health and safety or that of a loved one.

Special Note: One of the important black box warnings states never to abruptly stop this medication, but to decrease dosage gradually over time whenever possible.  More information on withdrawal adverse effects of EffexorXR and Effexor (venlafaxine)  be found further on in this article.

What is Effexor (Venlafaxine) Used For?

Effexor is approved by the FDA to be used for treating such conditions as:

  • MDD (Major Depression Disorder)
  • GAD (General Anxiety Disorder)
  • SAD (Social Anxiety Disorder, sometimes called Social Phobia)
  • PD (Panic Disorder)

In addition to the above approved uses, off label uses have become an option where other treatments for certain conditions were found unsuccessful.

Studies are sometimes done to explore the effectiveness of drugs, and where enough studies show a reasonable efficacy, the drug can eventually become approved for other purposes than the drug was originally approved for.

Such off-label uses for Effexor (venlafaxine) and EffexorXR currently include:

  • Treatment of hot flashes in menopause
  • Migraines, tension headaches
  • Diabetic Neuropathy
  • PTSD (post traumatic stress disorder)
  • Post breast cancer therapy neuropathy


Effexor (Venlafaxine) Alternative Names and Slang

Effexor (venlafaxine) has been marketed using hundreds of brand names around the world, including these interesting names:

  • Easyfor
  • Depressa
  • Nervix
  • Calmdown
  • Vexamode
  • Venjoy
  • Blossom

Venlafaxine hydrochloride is the full generic name for Effexor and EffexorXR. Hydrochloride is a kind of chemical binder used in manufacturing this and certain other drugs. Hydrochloride is an acid, like the hydrochloric acid found in the stomach, instrumental in digestion.

Note that Effexor has now been discontinued in the US due to causing excessive nausea, and has been replaced with the time-release version called EffexorXR.

No street or slang names have emerged, as the drug never became popularized as a stand-alone drug for recreational use. However, the drug has been shown up in batches of street drugs like MDMA or ecstasy, that when analyzed did contain random amounts of drugs such as venlafaxine or other prescription drugs.

Effexor (Venlafaxine) Side Effects

One of the most commonly reported negative side effects of venlafaxine is nausea. The drug manufacturer reports that it stopped making the immediate release form of Effexor in the US because of this negative effect, and replaced it with a time-release version called EffexorXR that was more easily tolerated.

However, a much more troubling side effect was that both versions of the drug were linked to a higher risk for mortality through overdose than other SSRI type antidepressant drugs, as reported in Wyeth Pharmaceutical’s 2006 letter issued to healthcare professionals, warning of this discovery that emerged after the drug was already on the market. The FDA also sent out a medical alert from its safety information program that was set up to advise consumers and caregivers of such adverse events relating to prescription drugs.

In addition to the drug overdose risk, there are vast numbers of side effects documented for venlafaxine and all of its trade names, including:

  • Serotonin Syndrome: a life threatening condition marked by sudden fever, sweating, muscle stiffness or muscle rigidity, trouble breathing, nausea, vomiting, hallucinations, rapid heart rate, agitation, etc.
  • Many drugs, including alcohol, can interact with SSNRI antidepressants, and can contribute to or enhance side effects including Serotonin Syndrome.
  • Elevated blood pressure
  • Suicidality emergence, thoughts of hurting oneself
  • Increased suicidality where already present
  • Loss of bone mineral density leading to fractures
  • Worsened depression
  • Worsened anxiety
  • Akathisia: a ceaseless internal restlessness often accompanied by constant need to be in motion, i.e., pacing, rocking, twisting, etc.
  • Seizure
  • Insomnia
  • Bouts of coughing
  • Aggressiveness
  • Hostility
  • Impulsive or erratic behaviors
  • Panic attacks
  • Dry mouth
  • Dizziness, vertigo
  • And many other negative physical, emotional, and cognitive side effects.


Effexor (Venlafaxine) Withdrawal Symptoms

In addition to the side effects that may be experienced by some persons taking Effexor (venlafaxine), other brand names, or EffexorXR, there are adverse effects that can accompany coming off this drug.

This collective set of withdrawal symptoms is often termed “Discontinuation Syndrome”. These discontinuation symptoms can be extreme and even life threatening, especially where the drug has been withdrawn abruptly or too quickly, but one should be aware that these can occur even during a careful and gradual taper, and include:

  • Brain zaps, feeling of electric shocks through the head and neck
  • Extreme fatigue
  • Headaches, migraines
  • Flu-like symptoms, ie., fever, chills, cramps, diarrhea, etc.
  • Insomnia
  • Brain fog
  • And many other adverse symptoms.

How Long do Effexor Withdrawal Symptoms Last?

The half-life of EffexorXR is anywhere from approximately 9 to 27 hours, and can begin within a few hours of the last dose. The half-life is the time that it takes for half of the total ingested dose to be cleared from the body. This half-life period is often extended to suggest that it is equivalent to the time a person may experience the manifestations of withdrawal. Each person’s individual metabolism and the genetic factors that dictate the metabolism, play a part in the rate of withdrawal. This can make it largely unpredictable to determine when the withdrawal is going to manifest, when it will abate, and the severity. People with a more rapid metabolism may endure a sharper withdrawal. Effexor has a comparably short half-life for antidepressants, and as such can result in a typically more abrupt manifestation of withdrawal. Even though the half-life definition of withdrawal is measured by a number of hours, people often report a protracted withdrawal that can continue for weeks, months, or even years, especially where adequate preparations and support have not been made available in the process.

It is extremely important to bear in mind the FDA warning on stopping EffexorXR all at once, which can introduce such a shock to the body that the withdrawals could be overwhelming and impossible to endure without medical intervention.

There are diet changes such as reducing sugar and caffeine that can help, as well as gentle exercise routines and organizing a daily schedule that allows for adequate rest and recuperation.

Discontinuing/Quitting Effexor (Venlafaxine)

Can I stop Taking Effexor Cold Turkey?

The FDA has issued clear recommendations against stopping Effexor (venlafaxine) or EffexorXR too quickly and certainly warns against a “cold turkey” approach. To do so can lengthen the time needed to recover from quitting the drug.

When a person has been taking venlafaxine or any prescription drug for a period of time, the body begins compensating in many different ways that are not always obvious. The abrupt cessation of a drug that the body has become dependent on can introduce such shock at such a rapid pace, that the change is profoundly unsettling, and can be life-threatening in some cases.

Never attempt to discontinue a drug suddenly. Always seek medical professional help and guidance before quitting Effexor (venlafaxine), EffexorXR, or any prescribed drug.

Effexor (Venlafaxine) FAQs

Below are some of the most common questions and requests for information concerning EffexorRX and Effexor (venlafaxine). We recommend always researching any drug before commencing a prescription, because in the rush of a doctor or clinic visit, time is not always set aside for education. Where a prescription has been started, but has not provided the benefits that were sought, it can be highly beneficial to inform oneself as much as possible about the reasons that a prescription based treatments were not as successful as one hoped.

Can Venlafaxine Make You Gain Weight?

Yes, some people gain weight while taking venlafaxine. This may be attributed to the drug having a stimulating effect upon appetite.  There may be other contributing factors, which are not yet understood about why people will gain weight on this drug.

Does Effexor Have Caffeine?

No, Effexor does not contain caffeine. However, caffeine has been shown to interact negatively with venlafaxine because both drugs can raise blood pressure.  Drinking coffee can also add to feelings of restlessness or agitation, which are symptoms that Effexor can also cause.

Can Effexor Cause Memory Loss?

Yes, any drug which causes inability to focus, causes a person to lose concentration, etc., can have a detrimental effect on memory over time. After all, it may be hard to remember something you were not able to concentrate on in the first place. (3)

What Are ‘Brain Zaps?’ Can Effexor Withdrawal Cause Brain Zaps?

“Brain Zaps” are a commonly reported withdrawal symptom that happens when coming off antidepressant drugs such as Effexor (venlafaxine) and EffexorXR. While it is not known exactly why they occur during drug withdrawal, the feeling of an electrical jolt or shock through the head and neck area at unexpected times can be overwhelming to endure. The electrical zap is often accompanied by nausea, ringing in the ears and other unsettling symptoms.  The sensation can affect the entire head, or can move from one part of the brain to another. These jolts can occur occasionally or frequently, and can range from moderately to extremely severe, without warning, and often increase overall general anxiety and stress.

Treatment for Effexor (Venlafaxine)  Abuse and Addiction?

Over more than a decade, ATMC has worked with thousands of clients who were seeking positive improvements to their mental health or other conditions, such as medication dependence or addiction, and for whom prescription drugs did not produce the desired outcome.

Using a well-refined and carefully developed regimen of safe and effective protocols, the center has become a world leader in helping people reach these types of goals with vibrant success.

The expertise and knowledge that is offered to our clients is not only grounded in our longstanding heritage of individual care and attention, but the program we offer is significantly augmented because it is delivered in a compassionate, warm, social setting. We have much information to readily offer on request. Our goal is to make the information easily available to any person who is searching for the most streamlined and effective treatment plan possible.

This content has been reviewed, and approved by a licensed physician.

Dr. John Motl, M.D.

Dr Motl is currently certified by the American Board of Psychiatry and Neurology in Psychiatry, and Board eligible in Neurology and licensed in the state of Arizona.  He holds a Bachelor’s of Science degree with a major in biology and minors in chemistry and philosophy. He graduated Creighton University School of Medicine with a Doctor of Medicine.  Dr. Motl has studied Medical Acupuncture at the Colorado School of Traditional Chinese Medicine and at U.C.L.A.

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