Side Effects When Starting Sertraline
Most side effects of sertraline emerge within the first few weeks of treatment and are generally mild and transient, with the most common being gastrointestinal symptoms (nausea, diarrhea), headache, insomnia or drowsiness, dizziness, increased sweating, and sexual dysfunction. 1
Common Early Side Effects (First Few Weeks)
Gastrointestinal symptoms are the most prominent early adverse effects: 2, 3, 4
- Nausea (most common reason for discontinuation in clinical trials) 1
- Diarrhea or loose stools 1, 3
- Loss of appetite 2
- Indigestion or dyspepsia 3
Neurological and sleep-related effects: 1
- Headache 1, 5
- Dizziness 1, 5
- Insomnia or increased sleepiness 1, 2, 5
- Vivid dreams 1
- Tremor or shaking 1, 2
- Increased sweating (including night sweats, which is dose-related) 6, 5
- Dry mouth 1, 5
- Fatigue or feeling tired 1, 2
- Nervousness or agitation 1, 2
Sexual dysfunction (more prominent in adolescents and adults): 1
Serious Side Effects Requiring Immediate Medical Attention
Serotonin syndrome (medical emergency, can occur within 24-48 hours, especially when combined with other serotonergic medications): 1, 2
- Mental status changes: confusion, agitation, anxiety 1
- Neuromuscular hyperactivity: tremors, muscle rigidity, hyperreflexia, uncontrolled muscle spasms 1, 2
- Autonomic instability: high fever, rapid heart rate, high blood pressure, sweating, vomiting, diarrhea 1, 2
- Advanced symptoms: seizures, loss of consciousness 1, 2
Behavioral activation/agitation (more common in younger patients and those with anxiety disorders, typically occurs early in treatment or with dose increases): 1
- Motor or mental restlessness 1
- Impulsiveness, talkativeness 1
- Disinhibited behavior, aggression 1
- Insomnia 1
- This usually improves quickly with dose reduction, distinguishing it from mania which persists 1
Suicidal thinking and behavior (FDA boxed warning through age 24): 1
- Risk is highest during the first 1-2 months of treatment 1
- Absolute risk is 1% vs 0.2% with placebo (number needed to harm = 143) 1
- Monitor for emergence of agitation, irritability, or unusual behavioral changes 1
Other serious but rare effects: 1
- Abnormal bleeding (especially with concurrent NSAIDs or aspirin): ecchymosis, nosebleeds, petechiae 1
- Seizures (use cautiously in patients with seizure history) 1
- Mania or hypomania (typically appears later in treatment, not in first month) 1
When to Seek Medical Attention
Seek emergency care immediately if: 1, 2
- High fever with muscle stiffness and confusion (serotonin syndrome) 2
- Uncontrolled muscle spasms 2
- Rapid changes in heart rate or blood pressure 2
- Loss of consciousness 2
- Seizures 1
Contact your healthcare provider promptly if: 1
- Suicidal thoughts or worsening depression 1
- Severe agitation, irritability, or unusual behavioral changes 1
- Severe or persistent nausea preventing adequate nutrition 1
- Abnormal bleeding or bruising 1
Monitoring and Management Strategy
Close monitoring is essential within 1-2 weeks of starting treatment: 1
- The American College of Physicians strongly recommends assessing patient status, therapeutic response, and adverse effects beginning within 1-2 weeks of initiation 1
- Risk for suicide attempts is greatest during the first 1-2 months 1
Most common side effects are mild, short-lived, and decrease with continued treatment: 6, 7
- Gastrointestinal symptoms typically diminish over time 7
- 10-20% of patients discontinue treatment due to side effects 6
Practical management of bothersome but non-dangerous side effects (like night sweats): 6
- Use lighter bedding and cooler bedroom temperatures 6
- Reassurance if medication is otherwise effective 6
- Consider alternative antidepressants if intolerable 6
Important caveat: Slow up-titration is recommended to minimize dose-related behavioral activation, particularly in younger patients and those with anxiety disorders. 1