Paroxetine is an SSRI antidepressant used for depression, anxiety, panic and obsessive-compulsive disorder. It shares the SSRI side-effect profile, with a few tendencies of its own: it is more sedating than some, more associated with weight gain, and its short duration of action makes discontinuation symptoms more pronounced than with most alternatives.
Common side effects and early adjustment effects
- Nausea, common early and often eased by taking it with food
- Drowsiness, which is more common with paroxetine than with several other SSRIs
- Dry mouth and constipation
- Sweating
- Headache and dizziness
- Increased anxiety or restlessness in the first week or two
- Blurred vision
Most ease within two to four weeks. If drowsiness is the problem, dose timing can often be moved to the evening. Do not drive until you know how it affects you.
Serious mood, behaviour or physical symptoms to take seriously
New or worsening thoughts of self-harm or suicide. Risk is highest in the first weeks and after any dose change, and is of particular concern in people under 25. Contact a doctor or emergency services urgently. Tell someone close to you what to watch for when you start.
Serotonin syndrome. Get emergency help for agitation or confusion together with fever, sweating, a racing heart, muscle twitching or stiffness, shivering and diarrhoea. See serotonin syndrome symptoms.
Low sodium. More common in older adults, presenting as confusion, marked weakness, unsteadiness or cramps. Diagnosed on a blood test.
Unusual bruising or bleeding, with risk higher alongside anti-inflammatories or blood thinners.
Also seek prompt help for a rash that blisters or peels, swelling of the face or throat, fainting or an irregular heartbeat, or a switch into elevated mood with reduced need for sleep and racing thoughts.
Sexual, sleep, weight and emotional side effects
Sexual side effects are common with all SSRIs and are reported more often with paroxetine than with several others. They include reduced desire, difficulty with arousal, and delayed or absent orgasm, and they frequently persist rather than settling. A dose change or switch may help, so raise them. See SSRI sexual side effects.
Weight gain is more associated with paroxetine than with most SSRIs and tends to develop over months rather than weeks. Worth tracking from the start. See antidepressants and weight gain.
Sedation can be useful if sleep is disturbed and unwelcome during the day. Emotional blunting is reported and may respond to a dose change. See emotional numbness on antidepressants.
Interactions, alcohol, pregnancy and other risk factors
- Other serotonergic medicines. Tramadol, triptans, other antidepressants and some cough preparations.
- St John’s Wort. Should not be combined. See St John’s Wort and antidepressants.
- Anti-inflammatories, aspirin and blood thinners. Increase bleeding risk.
- Tamoxifen and some other medicines. Paroxetine affects a liver enzyme that processes several medicines, so mention it whenever anything new is prescribed.
- Alcohol. Worsens drowsiness. See mental health medication and alcohol.
- Pregnancy. Paroxetine specifically warrants discussion in pregnancy, and an alternative is sometimes preferred. Do not stop on discovering a pregnancy without advice, since untreated illness carries its own risk. See mental health medication in pregnancy.
What to ask your doctor before changing dose or stopping
Paroxetine leaves the body quickly, which makes discontinuation symptoms more likely and more intense than with longer-acting SSRIs: dizziness, electric-shock sensations, irritability, nausea, vivid dreams and flu-like feelings. Even missing a single dose can bring them on.
This is not addiction, but stopping needs a slower, carefully planned reduction. Take it consistently at the same time each day. See discontinuation symptoms.
- What should I do if I miss a dose?
- If I want to stop eventually, how slowly would we go?
- Would a different antidepressant suit me better given weight or sexual side effects?
- Is this the right choice if I may become pregnant?
- Which painkillers are safe alongside this?
Related mental health medication guides
- Antidepressant side effects
- Mental health medication side effects
- Should I stop my mental health medication
- Stopping antidepressants
- Report a side effect in South Africa
See also SSRI side effects.
Medical Disclaimer: This content is for informational and educational purposes only and does not constitute medical diagnosis, prescription, or professional advice. Always read the patient information leaflet and consult a qualified doctor or pharmacist regarding any medicine or health concern.