Pharmacology · Selective serotonin reuptake inhibitors (SSRIs)
Sertraline !
A widely used SSRI for depression and anxiety disorders, including PTSD and OCD. It blocks serotonin reuptake and is often a first choice.
Updated 2026-11-01
The figure shows sertraline bound at the central site of a thermostabilised human SERT (ts3).
Mechanism of action
Sertraline binds the central substrate site of the serotonin transporter and blocks serotonin reuptake, strengthening serotonergic signalling in the brain. Clinical improvement follows over weeks as the system adapts.
- Sertraline binds the central site of the serotonin transporter
- Serotonin reuptake is blocked
- Serotonin signalling in limbic and cortical circuits increases
- Depression and anxiety improve over weeks
Pharmacokinetics
- Absorption
- By mouth, with or without food
- Metabolism
- Extensive in the liver to N-desmethylsertraline, which is much less active
- Half-life
- About 26 hours for sertraline; 62 to 104 hours for N-desmethylsertraline
- Onset and duration
- Benefit builds over several weeks
Indications
- Major depressive disorder
- Obsessive-compulsive disorder
- Panic disorder
- Post-traumatic stress disorder
- Social anxiety disorder and premenstrual dysphoric disorder
Adverse effects
Common
- Nausea and diarrhoea
- Insomnia or somnolence
- Sexual dysfunction (ejaculatory delay, low libido)
- Sweating, tremor, dizziness
Contraindications
- MAO inhibitors, including linezolid and intravenous methylene blue, or within 14 days of stopping an MAOI
- Pimozide
- Known hypersensitivity to sertraline
Key interactions
- MAO inhibitors, triptans, tramadol, fentanyl, lithium, St John's wort
- Serotonin syndrome
- NSAIDs, aspirin, warfarin
- Higher bleeding risk
- Pimozide
- Higher pimozide levels and QT prolongation
- Urine screening tests for benzodiazepines
- False-positive results
What is monitored
- Mood and suicidal thoughts, especially early and after dose changes
- Signs of mania
- Sodium in older adults
- Bleeding when combined with antithrombotic drugs
Administration and safety
- Given by mouth, with or without food
- Stopped gradually rather than abruptly to avoid a discontinuation syndrome
- A false-positive benzodiazepine urine screen is possible; confirmatory testing clarifies it
Nursing care
- Assess suicide risk at baseline and during the first weeks; teach families the warning signs
- Explain that improvement takes weeks and that early nausea or sleep changes often settle
- Teach that abrupt stopping can cause dizziness, «electric-shock» sensations, irritability and insomnia
- Watch for bleeding with NSAIDs or anticoagulants, and for confusion from low sodium in older adults
Pregnancy and breastfeeding
Studies of first-trimester use do not show a clear rise in major malformations; exposure late in pregnancy is linked to neonatal adaptation problems, persistent pulmonary hypertension and postpartum haemorrhage.
Test yourself
Think of the answer, then tap the question to see it.
Which SSRI has approved indications that include PTSD, OCD, panic disorder and premenstrual dysphoric disorder?
Sertraline.
A patient on sertraline has a positive urine screen for benzodiazepines without taking any. What explains it?
Sertraline can cause false-positive benzodiazepine screening results; a confirmatory test (such as chromatography with mass spectrometry) distinguishes them.
What symptoms suggest a discontinuation syndrome after stopping sertraline abruptly?
Dizziness, nausea, sweating, irritability, anxiety, insomnia and sensory disturbances such as electric-shock sensations. Gradual tapering reduces the risk.
Related drugs
← Back to the class: Selective serotonin reuptake inhibitors (SSRIs)
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - SERTRALINE HYDROCHLORIDE tablet (DailyMed (U.S. National Library of Medicine), 2026); Sertraline: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2025); 6AWO: X-ray structure of the ts3 human serotonin transporter complexed with sertraline at the central site (RCSB Protein Data Bank, 2017).
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Representative model, for educational purposes only.