How SSRIs Work to Help Hot Flashes
SSRIs help reduce hot flashes by affecting serotonin levels in the brain, which plays a role in temperature regulation, with studies showing they can reduce hot flash frequency by up to 65% within the first week of treatment. 1
Mechanism of Action
- SSRIs work through a mechanism that is independent and more rapid than their antidepressant effect, specifically targeting the brain's temperature regulation centers 2
- By preventing the reuptake of serotonin in the brain, SSRIs increase serotonin availability, which helps stabilize the thermoregulatory zone that becomes disrupted during menopause 3
- The effect on hot flashes typically begins rapidly, often within less than a week of starting treatment 3
Effectiveness for Hot Flashes
- SSRIs can reduce hot flash frequency and severity by approximately 60-65% compared to about 38% with placebo 4, 1
- Paroxetine, citalopram, and escitalopram have shown the highest efficacy and fewest side effects among the SSRIs for treating menopausal hot flashes 5
- The recommended starting dose for paroxetine is low (7.5 mg daily) to minimize side effects while still providing benefit 2
- For women with moderate to severe hot flashes, SSRIs are considered a first-line non-hormonal treatment option 3
Side Effects and Tolerability
- Common side effects include dry mouth, blurred vision, and sexual dysfunction, but these are typically mild and often resolve within the first week of treatment 3, 6
- Side effects are dose-dependent, which is why lower doses are used for hot flash treatment than for depression 2
- Approximately 10-20% of women discontinue treatment due to side effects, which is lower than with some other non-hormonal options 3
- SSRIs should be tapered gradually when discontinuing to prevent withdrawal symptoms 2
Important Cautions
- Women taking tamoxifen for breast cancer should avoid paroxetine and fluoxetine as these SSRIs inhibit CYP2D6, which can block the conversion of tamoxifen to its active metabolites 3, 2
- For women on tamoxifen, alternative options like venlafaxine (an SNRI) or newer treatments like fezolinetant may be more appropriate 7, 2
- SSRIs are contraindicated in women taking monoamine oxidase inhibitors and should be used cautiously in women with bipolar disorder 3
- If there is no response after 4 weeks of treatment, the SSRI is unlikely to be effective and an alternative treatment should be considered 3
Practical Considerations
- SSRIs work faster for hot flashes than they do for depression, with benefits often seen within the first week 3, 2
- Treatment can be continued as long as hot flashes remain problematic, with periodic reassessment 2
- For women experiencing sleep disruption due to nighttime hot flashes, augmentation with a sleep medication may provide additional benefit 8
- If one SSRI is not effective, trying another SSRI or switching to an SNRI like venlafaxine may be beneficial 3, 6