How It Works
Selective serotonin reuptake inhibitors (SSRIs) affect the brain's use of a neurotransmitter chemical called serotonin, which is thought to have a role in regulating body heat.1 Increased serotonin use by the brain can also improve perimenopausal mood swings and irritability.
Venlafaxine affects the brain's serotonin and norepinephrine levels. How it affects hot flashes is not known. Mood may also improve with venlafaxine use.
Why It Is Used
Select antidepressants are used to treat hot flashes affecting menopausal women.1 They may also help with irritability, depression, and moodiness. They can be used before and after menopause as a symptom treatment alternative to hormones (birth control pills or hormone replacement therapy [HRT]).
Antidepressant therapy helps many men and women with hot flashes from cancer treatment.
Do not take venlafaxine if you:
- Have had an allergic reaction to this medicine in the past.
- Are currently taking an MAOI (monoamine oxidase inhibitor). This is an antidepressant and antianxiety medicine. Examples include isocarboxazid (Marplan), phenelzine sulfate (Nardil), and tranylcypromine sulfate (Parnate).
How Well It Works
Studies have shown that these antidepressants help relieve hot flashes in the majority of women treated.2
- In a randomized, controlled trial of paroxetine (Paxil) for postmenopausal women having at least 14 bothersome hot flashes a week, researchers report that about 60% of women had at least a 50% reduction in the severity and number of hot flashes a day after 6 weeks of treatment.1
- Venlafaxine (Effexor) lowers the number and severity of hot flashes for most women. This includes women with severe hot flashes from tamoxifen, a cancer-fighting hormone drug. In several studies, venlafaxine was most effective for hot flashes when used at a lower dose than is normal for treating depression.3
Side Effects
Possible SSRI side effects include:
- Headache.
- Nausea.
- Insomnia.
- Loss of appetite.
- Anxiety or nervousness.
- Drowsiness.
- Nightmares.
- Diarrhea.
- Loss of ability to reach orgasm during sexual activity.
- Dizziness or lightheadedness.
- High blood pressure.
Rare SSRI side effects include:
- Dry mouth.
- Constipation.
- Urination problems.
Time-released formulations and lower doses reduce the risk of side effects.1
Possible venlafaxine (Effexor) side effects are similar to those of SSRIs. Venlafaxine can also cause:
- Constipation.
- Weight loss.
- Dry mouth.
- A slight increase in cholesterol.
- Dilated pupils.
Other more serious side effects are rare but can include allergic reaction, fast heart rate, nausea, dizziness, anxiety, blurred vision, insomnia, increased blood pressure, and seizures. Because venlafaxine (Effexor) can increase blood pressure, it is used with caution in women with high blood pressure, heart failure, or glaucoma.
See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)
FDA Advisories. The U.S. Food and Drug Administration (FDA) has issued:
- An advisory on antidepressant medicines and the risk of suicide. The FDA does not recommend that people stop using these medicines. Instead, a person taking antidepressants should be watched for warning signs of suicide. This is especially important at the beginning of treatment or when the doses are changed.
- A warning about the antidepressants Paxil and Paxil CR and birth defects. Taking these medicines in the first 12 weeks of pregnancy may increase your chance of having a baby with a birth defect.
What To Think About
Using antidepressants to treat menopause symptoms is considered an off-label use for these medicines.
The side effects most commonly reported with paroxetine (Paxil) use for hot flashes were headache, nausea, and insomnia. About 58% of women reported side effects. (Interestingly, of women who were taking a placebo, about 53% also reported side effects. Similarly, about 43% of women taking a placebo reported a 50% or better improvement in hot flashes.)1
Further research is needed to determine the risks and benefits of long-term antidepressant treatment. But many people have used these medicines for long-term treatment of depression.
Never stop taking antidepressants abruptly. The use of any antidepressant should be tapered off slowly and only under the supervision of a doctor. Abruptly stopping these medicines can cause headaches, nervousness, anxiety, or insomnia.
Studies have found that daily use of SSRIs may increase the risk of bone fracture in adults over age 50. Before you take an SSRI, talk to your doctor about this risk.
Complete the new medication information form (PDF)
(What is a PDF document?) to help you understand this medication.
References
Citations
Stearns V, et al. (2003). Paroxetine controlled release in the treatment of menopausal hot flashes: A randomized controlled trial. JAMA, 289(21): 2827–2834.
North American Menopause Society (2004). Treatment of menopause-associated vasomotor symptoms: Position statement of the North American Menopause Society. Menopause, 11(1): 11–33.
Brigitte L, et al. (2004). Nonhormonal alternatives for the treatment of hot flashes. Pharmacotherapy, 24(1): 79–93.
Credits
| Author | Robin Parks, MS |
| Editor | Kathleen M. Ariss, MS |
| Editor | Maria Essig |
| Associate Editor | Pat Truman, MATC |
| Primary Medical Reviewer | Anne C. Poinier, MD - Internal Medicine |
| Specialist Medical Reviewer | Kirtly Jones, MD - Obstetrics and Gynecology |
| Last Updated | May 16, 2008 |