Effexor Side Effects

by on July 22, 2011


Common Effexor side effects include drowsiness, dizziness, strange dreams, blurred vision, weight fluctuation, mild nausea, and decreased libido. More serious side effects of Effexor include seizures, stiff muscles, fever, headache, severe nausea, and frequent bruising. In rare cases, it can also exacerbate glaucoma or cause hypertension.

Common Effexor Side Effects

The most commonly reported side effects of Effexor include the following:

  • Mild nausea or constipation (the most reported symptoms)
  • Headache
  • Decrease libido
  • Dry mouth
  • Blurred vision
  • Drowsiness
  • Sweating and unexplained nervousness
  • Strange dreams

Side effects such as bruising, bleeding, and fainting can also occur when Effexor is taken in conjunction with other antidepressants, blood thinners, or muscle relaxants, so it is important to inform a physician of any other medications before taking Effexor.

Serious Effexor Side Effects

Effexor Side EffectsThe following are more severe side effects. Any patient experiencing any of these conditions should contact their physician immediately:

  • Seizure
  • Difficulty breathing or tightness of the chest
  • Stiff muscles
  • Confusion
  • Irregular heartbeat
  • Tremors
  • Fever and hallucination
  • Severe nausea and vomiting
  • Easy and frequent bruising

Since Effexor may also increase pressure in the eye, in rare cases it may exacerbate preexisting conditions like glaucoma, or cause eye pain. It can also increase heart rate, which may cause pulmonary hypertension (high blood pressure in the pulmonary artery) in some patients.

Allergic Reactions

Some of the aforementioned serious side effects may signal the onset of an allergic reaction to Effexor, so it is important that they are addressed right away. Further indications of an allergic reaction include skin rash, hives, swelling of the face, tongue, and throat, insomnia, aggression, or impulsiveness. In some cases, paradoxical reactions may also indicate an Effexor allergy: these include mood swings, increased levels of anxiety or panic, or suicidal tendencies. In other words, if the drug appears to worsen the condition it was prescribed to treat, treatment should be altered or stopped.

Side Effects in Men and Women

Most men and women experience similar side effects of Effexor, with the only gender specific symptoms being those related to libido and sexual performance (i.e. men may experience difficulty ejaculating, and women may have trouble achieving orgasm).

However, the side effects in pregnant women are less well known. A 2010 study indicated that taking the drug may double the risk of miscarriage, while other research suggests little to no adverse effect on the fetus. Generally, it is not advisable for women who are pregnant to take Effexor unless absolutely necessary.

Side Effects in Children

Children under 18 are usually not prescribed Effexor, as the drug has been shown to cause a higher rate of suicidal thoughts and tendencies in this younger age group. In fact, the chances that depression, anxiety, and suicidal tendencies will actually increase while on the drug are increased for anyone up to the age of 25.

In a recent study, teenagers with a history of suicide attempts were asked to switch over to Effexor from a previous SSRI antidepressant. Results showed that after the switch, suicide attempts increased by over 60%.

Effexor is generally save for adults (preferably those over age 25) with no previous history of seizures or heart disease. It should also be avoided by anyone with an allergy to gelatin, cellulose, titanium dioxide, iron oxide, and hypromellose, as these are all inactive ingredients of the drug. Those without allergies or preexisting conditions will likely find the side effects of the drug to be minor, and most patients are able to tolerate it with little problem.