Effexor

venlafaxine

Common misspellings of this drug’s name:

• Efexor
• Afexor

Effexor (venlafaxine) is an antidepressant with a structure that does not resemble those of any other currently used antidepressant. Wyeth Pharmaceuticals, makers of Effexor, sent a two-page letter in August 2003 to healthcare workers in the US warning about the hazards of prescribing Effexor for children. The Wyeth letter states that Effexor was not effective in treating depression or anxiety and that there were increased “reports of hostility and especially in Major Depressive Disorder, suicide-related adverse events such as suicidal ideation and self-harm.”

Regulatory authorities in the United Kingdom announced new labeling restrictions for Effexor and Effexor XR in the U.K. on December 6, 2004, citing data from the U.K. Office of National Statistics that led them to conclude that Effexor is involved in a higher rate of overdose than SSRI medications like Zoloft and Prozac. The U.S. FDA announced it would review the U.K. data immediately.

Effexor is primarily prescribed for the treatment of depression and anxiety disorders. It has also been prescribed for off-label uses such as chronic fatigue syndrome, menopause, and obsessive-compulsive disorder, or OCD. Effexor can cause increases in heart rate and blood pressure and may be dangerous in patients with a history of heart disease or high blood pressure. It is extremely dangerous for patients who are currently taking monoamine oxidase inhibitors (MAOIs) to also take Effexor.

Effexor has a very short half-life, or time that it remains in the bloodstream, so it is usually prescribed in multiple daily doses or in its time-release formulation, Effexor XR. Its short half-life contributes to withdrawal symptoms that are said to be quite severe and include:

• Headache
• Nausea
• Fatigue
• Dizziness
• Anxiety (dysphoria)

Consumers should take care when stopping any prescription medication and follow the advice of their doctor in such cases. Antidepressant withdrawal symptoms may be minimized by a gradual tapering off of the drug level in the symptom rather than a complete stoppage of medication.

Sources:

U.S. Food and Drug Administration, “For Practitioners: Questions and Answers on Regulatory Changes for Antidepressant Drugs in the U.K.,” December 6, 2004.

Ed Silver, “Britain hits Wyeth drug with warning,” New Jersey Star-Ledger, December 7, 2004.