Medicine 1: Selective Serotonin Reuptake Inhibitors (SSRIs)

Medicine 1: Selective Serotonin Reuptake Inhibitors (SSRIs)

What is it?

Selective serotonin reuptake inhibitors (SSRIs) are anti-depressants that have been successful in reducing mood symptoms. This includes:

• Fluoxetine (Prozac)

• Paroxetine (Paxil, Pexeva)

• Sertraline (Zoloft)¹

How does it work?

These medications increase the concentration of a neurotransmitter (chemical messenger) in the brain called serotonin, which is thought to have a good influence on mood, emotion and sleep. After carrying a message, serotonin is usually reabsorbed by the nerve cells (known as "reuptake"). SSRIs work by blocking ("inhibiting") reuptake, meaning more serotonin is available to pass further messages between nearby nerve cells. .

But you have to take SSRIs for at least three months before they start working. They weren't found to be more effective when taken continuously rather than only during the second half of the cycle.

It's important for women who are considering taking antidepressants to know what side effects they could have. SSRIs can cause things like nausea, sleep problems, and decreased libido².

What is the efficacy?

Electronic searches for relevant randomized controlled trials (RCTs) were undertaken. Thirty-one RCTs were included in the review. They compared fluoxetine, paroxetine, sertraline, escitalopram and citalopram versus placebo. SSRIs reduced overall self-rated symptoms significantly more effectively than placebo.

Conclusion: SSRIs are effective in reducing the symptoms of PMS, whether taken in the luteal phase only or continuously. Adverse effects are relatively frequent, the most common being nausea and asthenia. Adverse effects are dose-dependent³.

Side effects:

Short-term effects: Nausea, decreased energy, drowsiness, fatigue, and sweating.

Long-term effects: Sexual disturbances, sleep disturbance, and weight gain.⁴

References

1. Chu A, Wadhwa R. Selective Serotonin Reuptake Inhibitors [Internet]. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2025 Jan– [cited 2025 Apr 23]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK554406/

2. Institute for Quality and Efficiency in Health Care (IQWiG). Premenstrual syndrome: Learn more – Treatment for PMS [Internet]. Cologne (DE): IQWiG; 2022 May 18 [cited 2025 Apr 23]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279264/

3. Marjoribanks J, Brown J, O'Brien PMS, Wyatt K. Selective serotonin reuptake inhibitors for premenstrual syndrome. Cochrane Database Syst Rev. 2013 Jun 7;2013(6):CD001396. doi:10.1002/14651858.CD001396.pub3.

1. Ferguson JM. SSRI antidepressant medications: adverse effects and tolerability. Prim Care Companion J Clin Psychiatry. 2001;3(1):22–7. doi: 10.4088/pcc.v03n0105.