Paroxetine | SSRI Uses, Warnings & Side Effects

Medication name

Paroxetine ("Pa-ROX-et-een")
Brand name

Seroxat ("se-ROX-at")
Medication type

Selective serotonin reuptake inhibitor (SSRI)

Tablets: 10mg, 20mg,30mg or 40mg strength

Liquids: 2mg per 1ml; 10mg per 5ml spoonful (UK product discontinued – now only available as a special order or imported product.)

If you are 18 or over, paroxetine can be prescribed for you as a licensed medicine for depression (low mood), panic disorder, OCD, PTSD and social anxiety disorder. It will usually be prescribed alongside a ‘talking therapy'.

If you are under 18, a specialist doctor may still consider this as a treatment option. However, other medicines will now usually be considered over paroxetine because there is more evidence to support their use or they are better tolerated.

Read our guide to depression

About paroxetine

Paroxetine is a type of antidepressant called a selective serotonin reuptake inhibitor (SSRI).

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, thinking, feelings and emotions. Research suggests that depression or low mood is more likely to occur when the brain doesn’t have enough serotonin.

Selective serotonin reuptake inhibitors (SSRIs) like paroxetine are thought to work by increasing levels of serotonin in the brain.

Depression, and other conditions like anxiety disorders, are not just caused by low serotonin levels, but a rise in serotonin levels can improve symptoms and help you to feel better.

Paroxetine and everyday life

Paroxetine should start helping with depression within one to two weeks. It may take four weeks or longer for you to get the full effect.

How people respond to treatment can vary. Sometimes improvement is slow, and you may not feel any different to start with. This can be hard when your mood is low, and if you experience any side effects form your medication you may think you feel worse and not better. If you can, give your medication a chance to work and continue to take it for at least three to four weeks to see if it makes a difference.

Your parents, friends and doctor may notice an improvement in you before you feel it yourself, so it’s a good idea to talk to them.

If you think your medicine has not made any difference to how you feel after three to four weeks, you should go back to your doctor. They might recommend a change in dose or a different medication. However, it can take longer to work for some people than for others, so they may suggest you wait six to eight weeks before deciding.

For anxiety and obsessive-compulsive disorder, it may take longer for the benefits to be noticed. It could take up to three months before you feel the full benefit.

For some people, anxiety symptoms briefly increase at the start of treatment, but this should decrease over time. To avoid or minimise this, your doctor will usually start treatment with a low dose and increase this after one to two weeks.

Paroxetine can make you feel less hungry than normal, which might lead to weight loss.

Some people find that they gain a little weight in the long term. This might be due in part to a return of appetite as your mood improves.

It is not possible to predict how paroxetine will affect each person before they start taking it. Talk to your doctor or pharmacist if you are concerned about your weight, or changes to your weight, while taking paroxetine.

A common side effect of paroxetine is a dry mouth. Over a long time, this can increase your risk of developing tooth decay or gum disease. Make sure you brush your teeth well and have regular dental check-ups. Speak to your dentist, doctor or pharmacist about things you can do to help.

You may want to let your family and friends know you are taking paroxetine so they can support you and help you look out for side effects.

For guidance on this, check out our page on getting support with your medication.

You can feel sleepy in the first few days of taking paroxetine. This should improve within a few weeks. If it makes you feel drowsy, try taking it just before you go to bed.

Some people find that paroxetine causes insomnia (difficulty getting to sleep), and vivid dreams or nightmares. If this happens, try taking the paroxetine first thing in the morning.

If you have been taking paroxetine for more than a month and you continue to feel very tired, sleepy or struggle to function during the day, you should go back to your doctor and discuss what changes could be made to help. This may include switching to a different medicine.

Alcohol

It may be possible to drink some alcohol while taking paroxetine but the two together might make you feel very sleepy and unsteady on your feet, especially when you first start taking the medication.

During the first few weeks of treatment, it is recommended that you don’t drink alcohol until you know how the medicine affects you.

Drinking alcohol every day, or in large amounts, can make your symptoms worse and may mean you won’t get the maximum benefit from your medication.

Street drugs

There is limited information about how paroxetine mixes with street drugs, but it is likely to be similar to other SSRIs.

Cannabis can make drowsiness worse with paroxetine and give you a fast heartbeat.

Cannabis and other drugs may have their own side effects on your mental health, like anxiety or psychosis.

Paroxetine could raise the level of cocaine in your body, giving you a bigger reaction. There may be an increased chance of having a seizure.

Taking paroxetine with cocaine, ecstasy or amfetamines could bring on serotonin syndrome. You could get a high temperature/fever, agitation, confusion, trembling or weird muscle movements. You need to go to hospital urgently if this happens. Tell the doctor everything that you have taken.

Methadone can make drowsiness worse with paroxetine. The paroxetine is likely to increase the concentration of methadone in your body. There is also an increased risk of serotonin syndrome.

There are many other street drugs, but we don’t know what effect taking them with paroxetine will have, so it’s best to be cautious. There is no regulation of street drugs or ‘legal highs’, so even if there are no known issues with the medication you take, the supply you receive might be mixed with other substances that could be dangerous.

Get more advice on our drugs and alcohol guide.

Paroxetine does not mix well with some other medicines, including herbal remedies. It may affect how they work or could cause more side effects.

Do not take paroxetine if you take an antidepressant medicine called a monoamine oxidase inhibitor (MAOI), or if you have taken one in the last two weeks. MAOIs include moclobemide, isocarboxazid, phenelzine and tranylcypromine.

Before you start taking paroxetine, tell your doctor if you are taking any other medications including things you have bought from a pharmacy or other shop for common illnesses like colds and flu or medications that you put on your skin.

Always tell the pharmacist that you are taking paroxetine if you buy any medicines from a pharmacy.

Look at the leaflet inside your medicine box for more information about other medicines that can interact with paroxetine. With some medicines your doctor may need to adjust the dose of your medicines if you take them together. Ask a doctor or pharmacist for more information if you have any questions.

There are several companies that manufacture this medicine and the non-active ingredients are likely to vary between products and different strengths of tablets available.

Always let your pharmacist know if you have any food allergies or intolerances, and always check with them if you’re concerned about any of the ingredients in your medication.

If you need to avoid animal products, please note that non-active ingredients used in the production of medicines may sometimes be of animal origin. Ask your pharmacist if you have any questions about the ingredients.

Further information about practical considerations for medicines if you need to avoid animal products can be found on the Vegan Society website.

Taking paroxetine may affect your ability to do things like driving a car, riding a bike, using machines, or anything else that needs a lot of focus.

You might find it difficult to concentrate, you might feel sleepy and your eyesight may be blurred.

It is recommended that you stop driving or riding a bike for the first few days or weeks until you know how it affects you.

Most people drive as normal while taking paroxetine. If you are worried about this or have any concerns you would like to discuss, speak to your doctor or pharmacist.

If you become pregnant while you are on paroxetine, you should carry on taking it and make an appointment to see your doctor as soon as possible They can discuss the benefits and risks of continuing paroxetine and help you to make a decision that is best for you and your baby. There may be a slightly higher risk of heart problems for your baby if you take paroxetine during the beginning of your pregnancy. Your doctor will explain the known risks to help you take the best treatment choice for you.

They may refer you to a specialist perinatal mental health team to support you with this decision.

You can find out more information about taking paroxetine during pregnancy at Bumps (Best Use of Medicines in Pregnancy).

Untreated depression or anxiety can also be harmful to you and your developing baby, so decisions about stopping or avoiding medication when you are pregnant need to be discussed carefully with your doctor. If you and your doctor agree that it is best for you to continue taking paroxetine while pregnant, you should tell your midwife. If you are planning to get pregnant, it is recommended that you take folic acid while you are trying for a baby and during pregnancy. It is safe to take this together with paroxetine.

If you are planning to get pregnant, it is recommended that you take folic acid while you are trying for a baby and during pregnancy. It is safe to take this together with paroxetine.

Post-natal

Some research shows that taking SSRI antidepressants, like paroxetine, in the month before you give birth can mean there is a small increased risk of bleeding after birth. Make sure to let your doctor and midwife know so they can monitor you.

Studies have shown that if paroxetine is taken in the last five months of pregnancy, there I an increased risk of persistent pulmonary hypertension of the newborn (PPHN). This occurs in the first 24 hours after birth and can make the baby breathe faster or look blue. If you’re concerned about this, speak with your doctor or midwife.

Some newborn babies whose mothers take paroxetine during pregnancy can get symptoms at birth or soon after, like feeding difficulties, restlessness or problems sleeping. Tell your midwife if you are taking paroxetine, so that they can help if the baby has any symptoms after birth.

Breastfeeding

Paroxetine is passed to the baby in breastmilk in small amounts.
If your baby was born early, then breastfeeding while you are taking paroxetine may not be recommended. Talk to your midwife and doctor about feeding options.

If you breastfeed while taking paroxetine, seek urgent medical advice if your baby becomes restless, very sleepy, or develops feeding problems.

Sex

Paroxetine can have side effects that affect your sex life. These include:

painful erections or difficulty getting an erection
bleeding from the vagina
difficulty reaching an orgasm
reduced genital sensation
lower sex drive

Some other rare side effects include breast growth or milk flow from the breasts (regardless of gender). These may affect your confidence and therefore your desire to have sex. Talk to your doctor if you get these symptoms.

There is some evidence which days that some of these side effects can continue for months after you’ve stopped taking your medicine. Talk to your doctor or pharmacist if you’re concerned about this.

Untreated depression or anxiety can have a negative effect on your sex life, so if paroxetine helps you to recover, positive effects can include improving your desire, experience and enjoyment of sex as your mood lifts and you become interested in life and relationships again.

Fertility

There is no evidence to show that paroxetine affects human fertility. Talk to your doctor about your paroxetine if you are trying to get pregnant or planning a family.

Paroxetine is not a banned substance in sport.

Most people play sports as normal while taking paroxetine, but if paroxetine affects your concentration, eyesight or co-ordination, then you may want to wait to see if those effects go away before playing sports that need a lot of focus. If you have any concerns, discuss this with your doctor. Taking paroxetine may affect your ability to do things like riding a bike, competitive gymnastics, or anything else that needs a lot of focus.

Paroxetine may affect your concentration, give you blurred eyesight and make you feel dizzy and tired.

Ideally it is best not to take paroxetine for the first time just before your exams.

It is not possible to predict how the medication will make you feel, and if you do get any side effects, these are more likely to occur when you first start taking paroxetine.

You should talk to your doctor about any future exams if you are starting paroxetine. You might decide together to delay starting it until you have done them.

If they are more than a month away, however, you might find that it is better to start paroxetine to lift your mood and improve your motivation and ability to study.

Most people take exams as normal while taking paroxetine, but if you have any concerns, discuss this with your doctor.

Information and safety considerations

Your doctor will consider any other medical conditions or symptoms you have before recommending a medicine for you.

Your medicine will come with a ‘patient information leaflet’. It’s important that you read this information. Speak to your pharmacist if:

you’re not given a leaflet
you don’t understand the information
you need it in a different format or language
you’re concerned about something you’ve read

The information leaflet also includes a list of warnings and precautions to consider before you take the medicine. If you think that any of these apply to you and are concerned that your doctor is not already aware of them, check with your doctor or pharmacist before you start to take your medication (or as soon as possible if you are already taking it).

Uses, warnings, safety and side effects

Taking paroxetine

Your doctor will advise you on how long it is best to keep taking your medication. This may vary depending on what you’re taking it for and how many times you’ve been unwell.

If you are prescribed paroxetine for low mood or depression, it is recommended that you take it for at least six months after you feel well again. This means that most people take it for at least seven to nine months. Research has shown that stopping it sooner, or immediately after you start to feel better, increases the risk of your low mood returning.

If you have had low mood or depression more than once, or if there is a higher risk of you becoming unwell again, your doctor may advise you to continue paroxetine for at least two years after you feel well again.

If you are prescribed paroxetine for anxiety or obsessional-compulsive disorder (OCD), it is recommended that you take paroxetine for at least one year after you feel well again. Research has shown that stopping it sooner, or immediately after you start to feel better, increases the risk of your symptoms returning.

If you have bipolar disorder, it is likely that the doctor will advise for the paroxetine to be stopped sooner. This is because, in bipolar disorder, there is a risk of your mood becoming too high if an antidepressant is used for too long.

You will get the best effect from paroxetine if you take it every day at the dose prescribed by your doctor.

You should start by taking it in the morning. This will lower the chance of it affecting your sleep. However, some people find this medicine makes them feel tired, so you may prefer to take it in the evening instead.

When you have worked out what time of day is best for you, it is recommended that you take your medication at roughly the same time every day. Try to get into a routine, like taking it when you have breakfast or 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.

If you remember later during the day, take it as soon as possible.

If you forget to take it by the time of your next dose, just take the next dose. Do not try and catch up by taking a double dose.

If you forget to take it for a few days, you may start getting withdrawal symptoms. Sometimes these can occur if you forget to take just one dose.

Withdrawal symptoms should improve quickly after you start taking paroxetine again. If they do not, seek advice from your doctor or pharmacist.

If you regularly forget to take it every day, your medicine may not work as well and it could increase the risk of you becoming unwell again.

Antidepressants are not addictive, but if stopped suddenly they can cause discontinuation or withdrawal symptoms. These are caused by the receptors and levels of chemical transmitters in your brain readjusting after you reduce or stop your medication (and can also occur if you miss doses of medication). These symptoms are more likely to occur with paroxetine than other antidepressants and may occur after just missing one or two doses.

If you have been taking paroxetine regularly for more than one to two months, it is recommended that you stop gradually (ideally over at least four weeks).

Some people find that very small dose reductions are needed when reducing and stopping this medicine. It may be that switching to a different type of SSRI medicine (which is also readily available in liquid form) can help if you are experiencing difficulties.

Discuss stopping your medication with your doctor. If you have important events coming up or going through a period of life which is very demanding, it might not be the best time to stop your medication. Planning and support are important to stopping your antidepressant medication successfully.

Some of the withdrawal symptoms you get may be like symptoms you had when you were unwell, so understandably, you might may you feel anxious or upset that your illness could be returning.

If you experience symptoms immediately or soon after stopping medication (days rather than weeks), this is usually a withdrawal symptom caused by your body adjusting to not having the medication anymore. If the symptoms start after a month or more after stopping your medicine, this might be a sign that you are becoming unwell again.

Withdrawal symptoms usually start within a few days of stopping (or sometimes reducing) your medication. A wide range of symptoms have been reported. You may experience a few or a range of these:

dizziness and/or feeling unsteady
headaches
numbness or tingling in hands or feet
sleep disturbances (vivid dreams, nightmares, not being able to sleep)
electric shock-like feelings in the head, spine, arms, legs or hands
feeling anxious, agitated or irritable and/or restless
confused or disorientated and reduced concentration
poor appetite, feeling or being sick or having diarrhoea (loose poo)
sweating or shaking
feeling emotional, low mood and tearful
flu-like symptoms/muscle aches and pains
tinnitus (ringing in your ears)
problems with your eyes, or fluttering/pounding heartbeat (these are not as common as the other symptoms listed above)

It is not possible to predict if you will experience withdrawal symptoms (or how bad they will be if you do experience them) but studies report about half of people may get them. The risk appears to be higher if:

you have been taking your medication for six to eight weeks and you stop taking it suddenly
you are a child or young person
you experienced an increase in anxiety symptoms when you started medication
you have experienced withdrawal symptoms with another antidepressant before

If you do experience symptoms, they are usually mild and don’t last long (two to three weeks for most people), but for a few these could be severe enough to make you feel very unwell and last longer (two to three months or more). Arrange an appointment with your doctor to discuss your symptoms and seek advice if you are concerned or unable to tolerate them.

You can stop taking paroxetine safely with your doctor’s help. Planning a gradual withdrawal together can help to minimise or prevent the withdrawal symptoms you experience.

Warnings and safety

If you have taken more than the dose prescribed by your doctor, contact NHS 111 immediately to ask for advice, or ask a family member or friend to do this for you. This is important even if you don’t feel any different.

NHS 111 can give you advice and direct you to the best place to get more help if you need it.

If you have taken too much medication on purpose, or if after taking this you quickly feel unwell, call 999 or get someone to take you to A&E straight away. This includes feeling drowsy or sleepy, feeling or being sick or notice a change in your heart rate or breathing.

If you need to go to A&E, do not travel alone or drive yourself there. Get your parent, family member or friend to go with you to support you and keep you safe on the way. If someone is not able to drive you there, call for an ambulance. Take your medication with you and tell doctors how much you have taken.

Suicidal thoughts

Depression (and other mental illnesses) can sometimes cause you to have thoughts about hurting yourself or taking your own life. While uncommon, this could also be a side effect of your medicine. This can happen to anyone but is more likely to happen if you are under 25 years old.

If you have any thoughts like this, it is important you get urgent help. Contact your doctor immediately for advice and support. This could be your GP or specialist mental health team. If you are able, share how you are feeling with family member or friend as well so they can support you to get help.

If you discussed with your doctor what to do if you get these thoughts and created a safety plan, read this to remind you who to contact for support and what you can do to help you cope.

Read our guide to suicidal feelings

Serious side effects

Paroxetine can cause rare but serious side effects, including allergic reactions.

Stop taking paroxetine and go to a hospital straight away if you get any of the following symptoms:

difficulty breathing
an allergic reaction or allergy (including symptoms such as swelling of your face, eyelids, lips, tongue or throat so that you cannot swallow or breathe or really bad itching of the skin with raised lumps)
fast, uneven heartbeat and fainting (this could mean a life-threatening condition called Torsades de Pointes)
any combination of: high fever, agitation, confusion, trembling, sweating, diarrhoea (loose poo), fast heartbeat or weird movements of your muscles (this could be serotonin syndrome)
you start having seizures or fits for the first time
you get a painful erection (priapism) that lasts more than two hours

Get your parent, family member or friend to take you or go with you to support you and keep you safe on the way. If someone is not able to drive you there, call for an ambulance. Take your medication with you.

Contact your doctor immediately but don't stop taking paroxetine, if you get any of the following symptoms:

your behaviour changes because you feel very happy, over-excited or aggressive
any unusual bleeding, including blood in your poo
tiredness, confusion and muscle-twitching (you may have a low blood-level of sodium)
yellowing of the skin or whites of the eyes (these may be signs of hepatitis)
if fits that you have had in the past happen more often
restlessness, or difficulty sitting or standing still
dizziness, feeling sick or being sick
your eyesight goes blurred and you have pain in your eyes

If you are unable to contact your doctor, call NHS 111 for urgent advice.

Side effects and your health

Side effects are more common when you first start taking paroxetine. Many go away as you continue your medicine. If they don’t get better, or if you are worried by them and they are causing you distress, speak to your doctor or pharmacist about them.

Very common side effects when taking paroxetine (affecting more than one in ten people) include:

nausea (feeling sick), which is why you should take paroxetine with food
decreased sex drive or sexual problems, including difficulty maintaining an erection (staying hard) and difficulty reaching orgasm (coming)

Common side effects (affecting up to one in ten people) include:

loss of appetite
higher blood cholesterol (seen in blood tests)
weight gain
finding it difficult to concentrate
feeling agitated
insomnia (sleep problems), unusual dreams, or sleepiness
dizziness and shaking
headache
dry mouth
blurred vision
feeling very weak
diarrhoea (loose poo) or constipation (difficulty pooing)
being sick
sweating more than usual
unusual yawning

Side effects that are more common in young people under 18 include:

an increase in thoughts of harming themselves or taking their own lives
deliberate self-harm
being hostile, aggressive or unfriendly
low appetite
shaking
excessive sweating
hyperactivity (having too much energy)
feeling agitated
changing emotions and moods, including crying

There are other side effects that you can get when taking this medicine. We have only included the most common ones here.

This list of side effects can look scary. You may not experience any of them, but it’s important to be aware of them so you know what to do if they do happen.

Unless your side effects are very severe or distressing, try to continue taking your medication until you can talk to your doctor. Your doctor can make changes to your medication to help if needed.

Uncommon but important side effects to be aware of include thoughts of harming yourself, thinking about taking your own life or trying to take your own life. This may be a symptom of your illness, including depression, but may be a side effect of medication. If you experience these thoughts, contact your doctor to seek immediate support to keep you safe.

Your doctor will make sure you are monitored carefully for these side effects, and you should decide with your doctor what to do if you experience these feelings while taking paroxetine. It’s a good idea to write these plans down and keep them somewhere safe.

If you are taking paroxetine and have not talked about this with your doctor, go back to them and talk it through. You might also want to talk to your parents, family member or friend about it too.

Another uncommon side effect is an increase in your risk of bleeding, including intestinal (stomach or gut) bleeding. Let your doctor know if you vomit blood or develop black or blood-stained poo.

There is no routine monitoring recommended before starting or while you are taking paroxetine, although your doctor may recommend specific tests, like a blood test, to help them make decisions about your medication.