Citalopram is effective for hot flushes with 10mg daily virtually as effective as higher doses, according to a controlled trial.

The authors of this trial note that the physiology of hot flushes is poorly understood, so while some SSRI have been shown to be effective treatment this cannot be assumed to be a class effect: in support, they note that not all SSRI have been shown to have similar efficacy (sertraline < fluoxetine / paroxetine). Those SSRI shown to be most effective, fluoxetine and paroxetine, interact with tamoxifen via CYP2D6 inhibition so an alternative SSRI that could be used safely with tamoxifen would be valuable in oncology. In this trial, they aimed to determine whether citalopram was effective in relief of hot flushes. Participants were postmenopausal women who reported at least 14 bothersome hot flushes per week for at least the past month. After a medication-free baseline week, they were randomised to 5 weeks treatment with 1, 2, or 3 citalopram 10mg capsules once daily or matching placebo in a 2:1 active:placebo ratio. Primary end point was the change from baseline to week 6 in hot flash score measured by prospective self-report: a 29% fall in this score is considered a large effect size.

In total, 254 patients were randomised (citalopram n=165, placebo n=83) and of these, 196 could be evaluated for the primary endpoint (132 and 64 respectively). In all three active treatment groups, the hot flash score fell significantly compared to the placebo group (reduction of 2.0; 23%), with no significant difference between the three doses: reductions were 7.0 (49%), 7.7 (50%), and 10.7 (55%) for 10, 20, and 30 mg respectively (P ≤ .002). Hot flush frequency also fell by similar amounts. Secondary outcomes were also improved in the citalopram group.

Citalopram was generally well tolerated overall with no unexpected adverse effects. Statistically, adverse event rates were similar in the active and placebo arms.

The authors conclude that citalopram is useful and well tolerated in the treatment of hot flushes. They found no dose response for the direct effect on hot flushes, however some secondary outcomes were better at 20mg daily than 10mg daily; 30mg daily was not associated with any significant further improvement and resulted in more adverse effects. Quality of life scoring suggested that a reduction of around 50% in frequency was required for a perception of improvement. The authors note that the trial was short, at only 7 weeks in total, and that longer studies to confirm efficacy and adverse effect profiles would be valuable. Overall, they suggest that citalopram offers a useful alternative for treatment of hot flushes, especially those on tamoxifen. A starting dose of 10mg daily may be sufficient.