Like all medicines, sertraline can cause side effects in some people, but many people have no side effects or only minor ones.
Some of the common side effects of sertraline will gradually improve as your body gets used to it.
Some people who take sertraline for panic attacks find their anxiety gets worse during the first few weeks of treatment. This usually wears off after a few weeks, but speak to your doctor if it bothers you. A lower dose may help reduce your symptoms.
Common side effects
These common side effects of sertraline happen in more than 1 in 100 people. There are things you can do to help cope with them:
Feeling sick (nausea)
Try taking sertraline with or after food. It may also help if you avoid rich or spicy food.
Headaches
Make sure you rest and drink plenty of fluids. It's best not to drink too much alcohol. Ask your pharmacist to recommend a painkiller. Headaches should usually go away after the first week of taking sertraline. Talk to your doctor if they last longer than a week or are severe.
Being unable to sleep
Take sertraline first thing in the morning.
Feeling sleepy
Take sertraline in the evening and cut down the amount of alcohol you drink. Do not drive, ride a bike or use tools or machinery if you're feeling sleepy. If this does not help, talk to your doctor.
Diarrhoea
Drink plenty of water or other fluids to avoid dehydration. Signs of dehydration include peeing less than usual and having dark, strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.
If you take the combined contraceptive pill or progestogen-only pill and you have severe diarrhoea for more than 24 hours , your contraception may not protect you from pregnancy. Check the pill packet for advice.
Dry mouth
Chew sugar-free gum or suck sugar-free sweets.
Feeling dizzy
If sertraline makes you feel dizzy, stop what you're doing and sit or lie down until you feel better.
Feeling tired or weak
If sertraline makes you feel tired or weak, stop what you're doing and sit or lie down until you feel better. Do not drive, ride a bike or use tools or machinery if you're feeling tired.
It's best not to drink alcohol as it will make you feel worse. If these symptoms do not go away after 1 or 2 weeks, ask your pharmacist or doctor for advice.
Keep taking the medicine, but speak to a doctor or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or does not go away.
Serious side effects
It happens rarely (in less than 1 in 100 people), but some people may have serious side effects when taking sertraline.
Book an appointment with your doctor if you get:
- changes in your periods, such as heavy bleeding, spotting or bleeding between periods
- weight gain or weight loss without trying
Call a doctor or call 111 now if:
- you have feelings of overwhelming happiness (euphoria), excessive enthusiasm or excitement, or a feeling of restlessness that means you cannot sit or stand still
- the whites of your eyes turn yellow, or your skin turns yellow (this may be less noticeable on brown or black skin) – these can be signs of liver problems
- you cough up blood or have blood in your pee
- you have black or red poo or blood in your vomit – these can be signs of bleeding from the gut
- you are bleeding from the gums, or get bruises that appear without a reason or that get bigger
Immediate action required: Call 999 or go to A&E now if you:
- get chest pain or pressure, or shortness of breath
- get headaches, have trouble focusing, have memory problems, cannot think clearly, have weakness, have a seizure or fit, or lose your balance – these can be signs of low sodium levels
- have thoughts about harming yourself or ending your life
- get severe dizziness or pass out
- get painful erections that last longer than 2 hours – this may happen even when you're not having sex
- get any heavy bleeding or bleeding that you cannot stop, such as cuts or nosebleeds that do not stop within 10 minutes
Do not drive to A&E. Ask someone to drive you or call 999 and ask for an ambulance.
Bring all the medicines you take with you.
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to sertraline.
Immediate action required: Call 999 now if:
- your lips, mouth, throat or tongue suddenly become swollen
- you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
- your throat feels tight or you're struggling to swallow
- your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
- you suddenly become very confused, drowsy or dizzy
- someone faints and cannot be woken up
- a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)
You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.
These can be signs of a serious allergic reaction and may need immediate treatment in hospital.
Do not drive yourself to A&E.
The person you speak to at 999 will give you advice about what to do.
Long-term side effects
A few people may get sexual side effects, such as problems getting an erection or a lower sex drive. In some cases these can continue even after stopping the medicine. Speak to your doctor if you are worried.
If you have diabetes, sertraline can affect your blood sugar levels. Your doctor may monitor you to check that you're on the right dose of diabetes medicine.
Other side effects
These are not all the side effects of sertraline. For a full list, see the leaflet inside your medicine packet.
Reporting side effects
You can report any suspected side effect using the Yellow Card safety scheme.
Visit the Yellow Card website for more information about reporting side effects.