Contributed by Linda Fugate, Ph.D.
My friend Pamela was one of the pioneers in trying venlafaxine for hot flashes. She started 10 years ago, before the Women's Health Initiative study of hormone therapy prompted many women and their doctors to take a closer look at non-hormonal options. Venlafaxine is the generic name for Effexor, which is FDA approved for depression and anxiety.
Pamela is a nurse with an active family. Like all of us, she wanted the most out of life in middle age. Hot flashes were in the way, so she went to see her doctor. He started her on a low dose of venlafaxine, which reduced the intensity of the hot flashes. Over the next few months, he increased her dosage to the maximum recommended, 225 mg per day. She was happy with this regimen until about a year ago, when she decided it time to move past menopause treatment. To her horror, she found that she couldn't function without the drug.
The biggest advantage to venlafaxine is its safety in terms of breast cancer risk. It is believed to have absolutely no estrogenic activity. Instead, it acts to increase concentrations of the neurotransmitters serotonin and norepinephrine.
I tried venlafaxine myself for depression after I got divorced. For me, the side effects were intolerable. I felt so nauseated, I thought I had caught a stomach bug. The usual spectrum of side effects bothers some patients: headache, dizziness, drowsiness, etc. But other patients feel fine while taking the drug.
The biggest disadvantage of venlafaxine is that after a few years, it's hard to get off. The manufacturer, Wyeth, provides a warning on its web site that after stopping the drug or decreasing the dose, “Reported symptoms include agitation, anorexia, anxiety, confusion, impaired coordination and balance, diarrhea, dizziness, dry mouth, dysphoric mood, fasciculation, fatigue, flu-like symptoms, headaches, hypomania, insomnia, nausea, nervousness, nightmares, sensory disturbances (including shock-like electrical sensations), somnolence, sweating, tremor, vertigo, and vomiting.” This is found in the Effexor XR Prescribing Information, under “Precautions, General, Discontinuation of Treatment.” The section explains that symptoms are more frequent with longer duration of treatment, but doesn't say how long you can take the drug without risking these symptoms.
Pamela is now tapering off venlafaxine very gradually. For all drugs that can be used for psychiatric conditions, the manufacturers recommend a gentle taper, regardless of whether the patient was taking the drug for psychiatric conditions or something else. Pamela hopes to be back to normal within a year.
Linda Fugate, Ph.D.
References:
Carroll DG, Nonhormonal therapies for hot flashes in menopause. Am Fam Physician, 2006 Feb 1;73(3):457-64.
Evans ML, Pritts E, Vittinghoff E, McClish K, Morgan KS, Jaffe RB, Management of postmenopausal hot flushes with venlafaxine hydrochloride: a randomized, controlled trial. Obstet Gynecol. 2005 Jan; 105(1):161-6.
http://www.wyeth.com/content/showlabeling.asp?id=100