Could the recent addition of buspirone (an anxiolytic) and increased dose of sertraline (a selective serotonin reuptake inhibitor) be causing my gastrointestinal distress, sexual side effects, restlessness, and insomnia, 8 days after starting the combination and 5 days after adding 15mg of buspirone daily?

Your Symptoms Are Likely Caused by Sertraline, Not Buspirone

The gastrointestinal symptoms, sexual dysfunction (reduced libido and delayed ejaculation), restlessness, and insomnia you're experiencing are classic adverse effects of sertraline (SSRI) that typically emerge within the first 1-2 weeks of treatment, and buspirone is unlikely to be the culprit—in fact, buspirone may actually help with some of these symptoms. 1, 2

Understanding the Timeline and Causation

Your symptom timeline strongly implicates sertraline as the primary cause:

• You've been on the combination for 8 days, meaning sertraline exposure has been sufficient to cause these effects 2
• Most SSRI adverse effects emerge within the first few weeks of treatment, particularly sexual dysfunction, GI symptoms, and activation symptoms like restlessness and insomnia 1, 2
• Buspirone was only added 5 days ago and typically does not cause the specific constellation of symptoms you're describing 3

Breaking Down Your Specific Symptoms

Gastrointestinal Distress

Sertraline causes significant GI side effects in a substantial proportion of patients:

• Nausea occurs in 25% of sertraline-treated patients (vs. 11% with placebo) 2
• Diarrhea/loose stools affect 20% of patients (vs. 10% with placebo) 2
• These GI symptoms are among the most common reasons for sertraline discontinuation 2, 4

Buspirone, by contrast, is not typically associated with significant GI distress at the 15mg daily dose you're taking 3

Sexual Dysfunction (Reduced Libido and Delayed Ejaculation)

This is a hallmark adverse effect of sertraline and SSRIs in general:

• Sertraline causes ejaculation failure (primarily delayed ejaculation) in 14% of male patients (vs. 1% with placebo) 2
• Decreased libido occurs in 6% of patients on sertraline (vs. 1% with placebo) 2
• Sexual dysfunction with SSRIs is vastly underreported in clinical trials, so actual rates are likely higher 5
• These sexual side effects typically emerge within the first few weeks of SSRI treatment 1

Importantly, buspirone does not cause sexual dysfunction and may actually improve it:

• The American College of Physicians notes there is no evidence supporting buspirone for managing SSRI-induced sexual dysfunction 5
• However, older research suggests buspirone normalized sexual function in 8 of 10 patients with anxiety-related sexual dysfunction 6
• A 2024 case report documented resolution of sertraline-induced delayed ejaculation after adding buspirone 7

Restlessness and Insomnia

These are classic "behavioral activation" symptoms caused by SSRIs, particularly early in treatment:

• Insomnia occurs in 21% of sertraline-treated patients (vs. 11% with placebo) 2
• Agitation/restlessness affects 5% of patients on sertraline (vs. 3% with placebo) 2
• Behavioral activation (motor or mental restlessness, insomnia, impulsiveness, agitation) is more common early in SSRI treatment and with dose increases 1
• The American Academy of Child and Adolescent Psychiatry specifically warns that behavioral activation may occur early in SSRI treatment and supports slow up-titration and close monitoring 1

Buspirone at 15mg daily is not typically associated with significant insomnia or restlessness 3

What You Should Do Next

Immediate Management Options

Contact your prescriber immediately to discuss the following evidence-based strategies:

1. Reduce the sertraline dose to the minimum effective level, as sexual dysfunction and other side effects are strongly dose-related 5

2. Continue the buspirone, as it may actually help mitigate some of the sexual dysfunction over time 6, 7

3. Consider switching to bupropion if symptoms persist, as it has significantly lower rates of sexual dysfunction (8-10%) compared to sertraline and is equally effective for depression 5, 8, 9

Important Caveats

• Do not abruptly discontinue sertraline, as this can cause withdrawal symptoms; any dose reduction should be done gradually under medical supervision 1
• The GI symptoms and activation symptoms often improve after 2-4 weeks as your body adjusts to the medication 4
• Sexual dysfunction, however, tends to persist throughout treatment and is less likely to resolve spontaneously 5, 2

If Switching Medications Becomes Necessary

Bupropion is the preferred alternative when sexual function is a major concern:

• Bupropion has sexual dysfunction rates of only 8-10% compared to sertraline's 14-20% 5, 8, 9
• Bupropion SR was statistically superior to sertraline in treating depression while causing significantly less orgasmic dysfunction in head-to-head trials 8, 9
• However, bupropion should not be used if you have a seizure disorder or are highly agitated 5