Sertraline — Depression & Anxiety Medication | KiwiMeds
✅ Reviewed by a Registered Pharmacist NZ | Last updated: May 2026 | This information is for educational purposes only and does not replace advice from your doctor or pharmacist.
What is sertraline?
Sertraline is an antidepressant belonging to a class called SSRIs (Selective Serotonin Reuptake Inhibitors). It is one of the most commonly prescribed mental health medicines in New Zealand. Brand names include Zoloft and Lustral, but generic sertraline is widely funded by Pharmac.
What is it used for? (NZ context)
Sertraline is used for depression, generalised anxiety disorder, social anxiety disorder, panic disorder, obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), and premenstrual dysphoric disorder (PMDD). It is funded by Pharmac and is a first-line treatment recommended by NZ guidelines for many of these conditions.
How does it work?
Sertraline increases the amount of serotonin available in the brain. It does this by blocking the reuptake (reabsorption) of serotonin back into nerve cells after it has been released. More serotonin available in the synaptic gap between nerve cells is thought to improve mood, reduce anxiety, and improve sleep. The exact mechanism of how this improves depression is still being researched.
How to take it
Always take sertraline exactly as directed by your doctor or pharmacist. Do not stop or change your dose without medical advice.
Common side effects
- Nausea — particularly in the first 1-2 weeks (taking with food helps)
- Headache
- Diarrhoea or loose stools
- Insomnia or drowsiness
- Dry mouth
- Increased sweating
- Sexual side effects (decreased libido, delayed orgasm) — common but often improve over time
- Initial increase in anxiety — some people feel more anxious in the first 1-2 weeks before improvement begins
Serious side effects to watch for
Sertraline carries a “black box warning” about suicidal thoughts in children, adolescents, and young adults particularly in the first weeks of treatment — this is a regulatory requirement. If you or someone you know has thoughts of self-harm, contact your GP immediately or call Lifeline NZ (0800 543 354). Serotonin syndrome is a rare but serious reaction — seek help immediately if you have agitation, confusion, rapid heart rate, high temperature, or muscle twitching.
Important drug interactions
- MAO inhibitors — never take together; serious and potentially fatal interaction (serotonin syndrome)
- Tramadol, some pain medicines — increased risk of serotonin syndrome
- Warfarin (blood thinners) — sertraline may increase bleeding risk; close monitoring required
- NSAIDs (ibuprofen, aspirin) — together increase bleeding risk, particularly GI bleeding
- Lithium — combination increases serotonin-related effects; careful monitoring needed
NZ-specific information
Pharmac funding: Sertraline is fully funded in New Zealand. Available as tablets (50mg, 100mg) and oral concentrate. Brand names in NZ: Zoloft (branded), Lustral (branded), generic sertraline (funded). When to expect improvement: Most people notice improvement in sleep and appetite within 1-2 weeks; mood usually improves by 4-6 weeks. Give it at least 4-6 weeks before concluding it is not working.
Frequently asked questions
Will I become addicted to sertraline? No — sertraline is not addictive in the traditional sense. However, stopping suddenly can cause withdrawal-like symptoms (dizziness, flu-like feelings). Always taper off slowly under medical guidance. How long should I take it? For a first episode of depression, most guidelines recommend continuing for at least 6-12 months after feeling better. Your doctor will help you decide.
Related medications
Metoprolol (blood pressure/heart) | Paracetamol (pain relief)
Always talk to your pharmacist or doctor for personalised advice. This information is general and educational — it does not replace a consultation with your healthcare provider.
References & Further Information
The following New Zealand and international resources were used to inform this page:
- New Zealand Formulary (NZF) — Sertraline — Depression & Anxiety Medication
- Pharmac — New Zealand Pharmaceutical Schedule
- Medsafe — New Zealand Medicines and Medical Devices Safety Authority
- BPAC NZ — Best Practice Advocacy Centre New Zealand
Related Medications
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Related Condition Guides
What is Sertraline used for?
Sertraline is an antidepressant (SSRI) used to treat depression, anxiety disorders, post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), and panic disorder. It is one of the most prescribed antidepressants in New Zealand.
Is Sertraline funded in New Zealand?
Yes, Sertraline is funded by Pharmac in New Zealand for eligible patients. It requires a prescription from a doctor.
How long does it take for Sertraline to work?
Sertraline usually takes 2 to 6 weeks to start working for depression and anxiety. Some improvement in sleep or anxiety may be noticed sooner, but the full antidepressant effect can take up to 12 weeks.
What are the common side effects of Sertraline?
Common side effects include nausea, diarrhoea, insomnia, dizziness, sweating, and sexual dysfunction. Most side effects are mild and tend to improve after the first few weeks of treatment.