How it works
What does paroxetine do?
Paroxetine is a type of antidepressant called a selective serotonin reuptake inhibitor (SSRI).
Research suggests that depression or low mood is more likely to occur when the brain doesn’t have enough serotonin.
Serotonin (also called '5HT') is a naturally-occurring chemical messenger (or “neurotransmitter”) that has an important role in areas of the brain that control mood and thinking.
Selective serotonin reuptake inhibitors (SSRIs) - like paroxetine - are thought to work by increasing levels of serotonin in the brain. They do this by blocking the recycling of released serotonin back into the nerve endings.
Paroxetine is often prescribed alongside a talking therapy.
How long does paroxetine take to start working?
It takes one to two weeks for paroxetine to start helping, and it could take some weeks or months to get its full effect. We believe this is due to adaptive changes needing to take place in the brain.
Your doctor might start you on a low dose and then increase it slowly over two to four weeks to your full dose.
How long will I need to take paroxetine?
You and your doctor should talk about how long you need to take paroxetine before you start your treatment.
Your doctor needs to know if...
You need to talk to your doctor or pharmacist before starting treatment with paroxetine if you have any of the following:
- eye problems, such as glaucoma (increased pressure in the eye)
- low sodium levels
- diabetes (high sugar levels in your blood)
- a tendency to develop bruises or to bleed easily (bleeding disorders)
- kidney or liver problems
- heart problems
- seizures (fits)
- thoughts of harming yourself or taking your life
- treatment with electroconvulsive therapy (ECT)
Some manufacturers include lactose and Sunset Yellow in their tablets. Talk to your pharmacist if you have any concerns about the ingredients.
The liquid medicine contains sorbitol (E420). If you have been told by your doctor that you have an intolerance to fructose, contact your doctor before taking Seroxat suspension.
The oral suspension also contains methyl parahydroxybenzoate (E218), propyl parahydroxybenzoate (E216) and sunset yellow FCF (E110), all of which can cause allergic reactions.
You should only take paroxetine as agreed with your doctor.
You will get the best effect from paroxetine if you take it every day at the dose prescribed by your doctor.
Make sure that you know your dose. If it is not written on the label, check with your pharmacist or doctor.
Choose a time each morning that you can always remember to take your paroxetine. This could be with breakfast, or when you brush your teeth.
Take it after food. This helps to prevent feelings of sickness.
Swallow the tablet with a drink of water - if you chew it, it tastes bitter.
What if I miss a dose?
If you remember later during the day, take it as soon as possible.
You may find it difficult to sleep if you take it towards bedtime.
If you forget to take it by the time of your next dose, just take the next dose.
Do not take a double dose.
What will happen if I forget to take my paroxetine?
If you forget to take it for a few days, you may start getting withdrawal symptoms. Talk to your doctor if this happens to you.
Stopping the use of paroxetine
Stopping paroxetine quickly, or reducing the dose too much at once, may cause uncomfortable symptoms Paroxetine is well known for more readily causing unpleasant effects if you stop it quickly, but you can stop taking it safely with your doctor’s help.
Once you start taking an SSRI, the brain adjusts to having a new level of serotonin around. If you stop taking the SSRI all at once, the balance starts to change again. You could get some symptoms from the change.
Some of the symptoms you might get include:
- dizziness or headaches
- tingling feelings like pins and needles, or electric shocks, including in the head
- sleep disturbances (vivid dreams, nightmares, not being able to sleep)
- tinnitus (ringing or other noises in the ear)
- feeling anxious, restless, agitated, confused or disorientated
- feeling emotional or irritable
- feeling sick or being sick
- diarrhoea (loose poo)
- sweats (including night sweats)
- problems with your eyesight
- a fluttering or pounding heartbeat
These symptoms should go away after two weeks for most people, but some people can get them for a few months.
Most people get mild symptoms, but for some people they can be very intense.
Go and speak to your doctor if you have missed a few doses or have decided to stop taking your medication.
The information on this page was reviewed by the College of Mental Health Pharmacy in March 2020.