From the Guidelines
Fluoxetine is the most appropriate Selective Serotonin Reuptake Inhibitor (SSRI) for patients concerned about weight gain, as it has been associated with weight loss in the short term and weight neutrality in the long term. According to the study published in Gastroenterology 1, fluoxetine and sertraline are the SSRIs that have been associated with weight loss with short-term use and weight neutrality with long-term use.
Key Considerations
- The choice of SSRI should be guided by the individual patient's circumstances, including their specific type of depression and other health conditions.
- Other SSRIs, such as paroxetine, have been associated with a greater risk of weight gain 1.
- Bupropion, a norepinephrine and dopamine reuptake inhibitor, is the only antidepressant that has been shown to consistently promote weight loss, but it may not be suitable for all patients with depression due to its activating effects and potential to exacerbate anxiety or bipolar disorder 1.
- Regular monitoring with a healthcare provider is essential to assess both the effectiveness and side effects of any SSRI.
Treatment Approach
- The typical starting dose for fluoxetine is 20mg daily, which can be adjusted based on response and tolerability.
- Patients should be aware that full therapeutic effects may take 4-6 weeks to develop, and these medications should not be stopped abruptly but tapered under medical supervision.
- SSRIs work by increasing serotonin levels in the brain, which helps regulate mood, but this same mechanism can sometimes affect appetite and metabolism, leading to weight changes.
Individual Response
- Individual responses to SSRIs can vary significantly, and weight changes can be influenced by genetic makeup, metabolism, lifestyle factors, and the specific condition being treated.
- Regular monitoring and open communication with a healthcare provider can help mitigate potential side effects and ensure the best possible outcome.
From the FDA Drug Label
As with other SSRIs, decreased appetite and weight loss have been observed in association with the use of sertraline In a pooled analysis of two 10-week, double-blind, placebo-controlled, flexible dose (50 to 200 mg) outpatient trials for major depressive disorder (n=373), there was a difference in weight change between sertraline and placebo of roughly 1 kilogram, for both children (ages 6 to 11) and adolescents (ages 12 to 17), in both cases representing a slight weight loss for sertraline compared to a slight gain for placebo.
The best SSRI that does not cause weight gain is sertraline, as it has been associated with decreased appetite and weight loss in some patients, and studies have shown a slight weight loss compared to placebo 2.
From the Research
Selective Serotonin Reuptake Inhibitors (SSRIs) and Weight Gain
- SSRIs are a class of antidepressants that can have varying effects on weight, with some causing weight gain and others potentially leading to weight loss 3, 4, 5.
- The study of fluoxetine, a specific SSRI, has shown that it is associated with weight loss during acute treatment, but weight gain during long-term treatment is similar to that of a placebo 4.
- Another study found that fluoxetine has a good safety profile and is effective in treating obsessive-compulsive disorder, with a recommended dose of 40 to 60 mg daily 6.
Comparison of SSRIs and Weight Gain
- A study comparing different SSRIs found that escitalopram, paroxetine, and duloxetine were associated with higher weight gain, while bupropion was associated with lower weight gain 5.
- Fluoxetine was found to have a similar weight gain profile to sertraline, with a difference of -0.07 kg (CI, -0.19 to 0.04 kg) 5.
- The study suggests that clinicians should consider potential weight gain when initiating antidepressant treatment, and that bupropion may be a good option for patients who are concerned about weight gain 5.