Zoloft (Sertraline) Side Effects
Sertraline is generally well tolerated, but patients should be aware of both common and potentially serious side effects, with the most frequent being gastrointestinal symptoms (nausea, diarrhea), sexual dysfunction, and sleep disturbances. 1
Common Side Effects (Occurring in ≥5% of Patients)
The FDA-approved labeling identifies the following most common adverse reactions that occur at least twice the rate of placebo 1:
Gastrointestinal
- Nausea (most common reason for discontinuation)
- Diarrhea/loose stools (sertraline has a higher rate of diarrhea compared to other SSRIs) 2
- Dyspepsia/indigestion
- Decreased appetite
Neurological
- Tremor or shaking
- Dizziness
- Headache
- Somnolence (sleepiness)
Psychiatric/Sleep
- Insomnia (20% vs 13% placebo)
- Agitation
- Fatigue
Sexual Dysfunction
- Ejaculation failure (8% in males)
- Decreased libido (6%)
- Erectile dysfunction (4% in males)
- Delayed or absent orgasm in females 1
Other
- Increased sweating (hyperhidrosis)
- Dry mouth
- Anxiety
Important timing note: Most adverse effects emerge within the first few weeks of treatment and are often transient 3.
Potentially Serious Side Effects
Black Box Warning: Suicidality
All SSRIs, including sertraline, carry an FDA black box warning for increased suicidal thinking and behavior in patients up to age 24 years. The pooled absolute risk is 1% for antidepressants versus 0.2% for placebo (number needed to harm = 143) 3. Close monitoring is essential, especially during the first months of treatment and after dose adjustments.
Behavioral Activation/Agitation
Motor or mental restlessness, insomnia, impulsiveness, talkativeness, disinhibited behavior, or aggression can occur, particularly:
- More common in younger children than adolescents 3
- Typically occurs early in treatment or with dose increases
- Supports the need for slow dose titration 3
Serotonin Syndrome
Life-threatening condition that can occur, especially when combined with other serotonergic drugs or MAOIs. Symptoms include 1:
- High fever
- Rapid changes in heart rate or blood pressure
- Uncontrolled muscle spasms
- Confusion
- Stiff muscles
Other Serious Adverse Effects
- Seizures (use cautiously in patients with seizure history) 3
- Abnormal bleeding (especially with concurrent NSAIDs or aspirin) 3
- Hyponatremia (low sodium levels)
- QTc prolongation (dose-related; caution in patients with risk factors) 1
- Mania/hypomania (rare, may appear later in treatment) 3
- Angle-closure glaucoma
Discontinuation Syndrome
Abrupt discontinuation can cause withdrawal symptoms, including dizziness, sensory disturbances, agitation, anxiety, nausea, and sweating. A slow taper is recommended when stopping sertraline 3.
Special Populations
Children and Adolescents
Additional side effects include 1:
- Abnormal increase in muscle movement or agitation
- Nose bleeds
- Urinary incontinence
- Aggressive reaction
- Possible slowed growth rate and weight changes (monitoring recommended)
Pregnancy and Breastfeeding
- Babies may have withdrawal symptoms after birth
- Increased risk for serious lung problems at birth
- Small amounts pass into breast milk 1
Clinical Pearls
Sertraline-specific considerations:
- Higher rate of diarrhea compared to other SSRIs 2
- May require twice-daily dosing at low doses (unlike most SSRIs) 3
- Sexual dysfunction rates are lower than paroxetine but present nonetheless 2
- Generally well tolerated in elderly patients without dose adjustment needed 4
Real-world data suggests that 38% of patients experience side effects, but only 25% consider them "very bothersome" or "extremely bothersome," and only 40% report them to their physicians 5. This underscores the importance of proactive inquiry about side effects during follow-up visits.
Patients should avoid alcohol while taking sertraline and should not drive or operate heavy machinery until they know how the medication affects them 1.