HeadMeds gives young people in the United Kingdom general information about medication. HeadMeds does not give you medical advice. Please talk to your Doctor or anyone else who is supporting you about your own situation because everyone is different. Please read more important details about our site.

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Chlorpromazine

Return to Chlorpromazine overview
  1. Use and Action
  2. Warnings and side effects
  3. Sex, drink, weight and everything else
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You should take chlorpromazine as agreed with your doctor

  • You will get the best effect from chlorpromazine if you take it regularly.
  • Make sure that you know your dose. If it is not written on the label, check it with your pharmacist or doctor.
  • You may start with a low dose taking the liquid, and then move on to tablets when your dose increases.
  • You may have to take your dose 3 or 4 times a day, but it is a long acting drug so avoiding the need to take a dose during the school day should be possible
  • Choose a time that you can always remember. This could be at mealtimes, or when you brush your teeth.
  • If you have to take your medicine at school or college, ask your doctor to talk to a teacher or school nurse about how you will do that. You may need a separate supply of medicine to keep at school - ask the pharmacist for help with that.
  • You can take the tablets or liquid before or after food.
  • Swallow the tablets whole with a drink of water - if you chew it, it tastes bitter.
  • You can mix the liquid medicine with a cold drink or food to make it easier to take.
  • A doctor or nurse can use the injection to give you a fast-acting dose of chlorpromazine if you are having serious symptoms.
  • You should stay laying down for 30 minutes after the injection - the doctor may check your blood pressure during this time.

If you forget to take a dose then just carry on from the next dose – do not take a double dose

What to do if you miss a dose of the tablets or liquid:

  • If you forget to take a dose by the time for the next dose, just start again with the next dose.
  • Do not take a double dose.

What might happen?

  • If you forget to take your medicine for a few days, you may start getting your old symptoms back, if this happens you should talk to your doctor.

You must go to A&E if you take too much

What to do if you take too much:

  • If you have taken more chlorpromazine than it said on the label, you must get help quickly – even if you do not feel any different.
  • Go to A&E. Take your medicine with you, to show to the doctors. Tell them how much you have taken.
  • Get a friend or family member to go with you, if you can, just in case you feel ill on the way.

You might get any of the following signs:

  • quick and shallow breathing
  • low body temperature
  • low blood pressure
  • restlessness
  • twisting of your arms and legs
  • fits (seizures)
  • unusual heartbeats
  • going unconscious and into a coma

It can take a few days for chlorpromazine to start helping you

  • It is hard to know – for each individual person – how long it will take for chlorpromazine to start working for you.
  • It could be as short as a few days.
  • If you have had no change by the end of 3-4 days, talk to your doctor about it.
  • Do not increase your dose yourself if you think it is not working.

Young people usually take chlorpromazine for months or years

You and your doctor should talk about how long you need to take chlorpromazine.

  • You will not get the full effect for a few days or weeks.
  • You should try an antipsychotic medicine for 4-6 weeks before you and your doctor decide if it is working or not.
  • You and your doctor need to decide how long you will need to take chlorpromazine depending on how long you have been unwell. You might need to take it for a few years, but you and your doctor should review your progress at least every year.

Tell your doctor or pharmacist before you take chlorpromazine if you have any of these conditions

You need to talk to your doctor or pharmacist before you take chlorpromazine if any of the following apply to you:

  • You have high blood sugar (with symptoms such as a great thirst, going to wee a lot, an increase in your appetite, and/or feeling weak)
  • You have ever had fits (seizures)
  • You have Parkinson’s disease
  • You have heart problems, or a family history of heart problems including strokes and heart failure
  • You have ever had blood clots, or you have a family history of blood clots
  • You have myasthenia gravis, with weak or tired muscles that can make it difficult to breathe
  • You have an underactive thyroid gland (hypothyroidism)
  • You have liver or kidney problems
  • You have glaucoma (raised pressure in the eye)
  • You have a condition called phaeochromocytoma (high blood pressure caused by a tumour near the kidney)
  • You have an enlarged prostate gland (men only)

If you start to get abnormal movements that you cannot control, you should go and see your doctor as soon as possible

  • Antipsychotic medicines can cause a wide variety of unusual movements affecting your muscles
  • Stiffness of the arms and legs or tremor may occur
  • If this happens go and see your doctor as it may be possible to reduce your dose, change to another medicine or add another drug such as procyclidine to treat this side effect
  • Sometimes you may get the muscles going in to spasm
  • If the movements are severe then you might find it difficult to speak, eat or breathe. You may find your eyes fixing and staring in a particular way.
  • See your doctor for prompt treatment to reverse these effects.
  • After taking chlorpromazine for some time you may get unusual movements that affect your lips and tongue.
  • This is called tardive dyskinesia. 
  • The first sign might be some movements of your tongue that you cannot control, and they may be quite regular and rhythmic.
  • The problem with tardive dyskinesia is that it might not stop, even if you stop taking your medicine.
  • If you notice it early and take action with your doctor, the problem should not get worse.
  • Go to see your doctor straight away if you have any of these symptoms.

Chlorpromazine has some side-effects, and if they happen they can be serious

Stop your medicine and go to a doctor or hospital straight away if you get any of the following symptoms:

  • Difficulty in swallowing, or any other symptoms like swelling in the mouth, tongue, face and throat, itching, rash, that could be an allergic reaction to the medicine
  • Muscles going stiff or rigid with high fever, sweating, looking pale, feeling strange and fainting or losing consciousness, or very rapid or irregular heartbeat (tachycardia) - this may be a serious and life-threatening side-effect called neuroleptic malignant syndrome
  • If a man gets a painful erection that lasts for a long time
  • Skin reactions - rashes, flaking of the skin or red blisters on the skin. Remember, you need to apply a high protection sunscreen before you go out in fine weather as chlorpromazine makes the skin more sensitive to sunlight
  • The whites of your eyes and skin become yellow in colour - this could be jaundice - look out for this especially in the first month of taking the medicine

Do not stop your medicine, but see a doctor straight away if you get any of the following symptoms:

  • Swelling, pain or redness in the leg, or chest pain and difficulty breathing - this may be due to a blood clot
  • Fast or unusual heartbeat, or chest pain round the heart that spreads to the shoulders, neck or arms with difficulty breathing (possible heart attack)

Do not stop your medicine, but see a doctor as soon as possible if you get any of the following symptoms:

  • Feeling down (depressed), agitated or not feeling any emotion about things
  • Having fits (seizures)
  • High temperature, chills and ulcers in your mouth and throat, sore throat and unusual tiredness - these can be a sign of problems in the blood that needs a test
  • Feeling dizzy when you stand up (low blood pressure)
  • Feeling very thirsty or wanting to go and pee a lot (high blood sugar)
  • Low body temperature
  • Finding it hard to go for a poo, or a change in the times when you do this

Some side-effects that do appear should get better after a few days. If they do not, you should go back to your doctor

Some side-effects of chlorpromazine may – strangely - seem like other mental health symptoms. Some side-effects here are also the opposites of each other. The balance of chemicals in the brain is very fragile, and hard to control! If they do not get better after a few days on the tablets, go back to the doctor.

Do not stop taking the tablets until you talk to your doctor, or you may get kick back as well as losing the benefit of your treatment.

Common side effects (could affect up to 1 in 10 people)

  • sleepiness
  • not feeling alert
  • tiredness
  • constipation (difficult to poo)
  • Finding it difficult to pee
  • dry mouth
  • stuffy nose
  • light headedness
  • blurred eyesight
  • weight gain
  • skin becomes very sensitive to sunlight

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

  • Please look at the leaflet inside your medicine box, or ask a doctor or pharmacist, if you want to know if you are getting a side-effect from your medicine.
  • If you do get a side-effect, please think about reporting it via the Yellow Card Scheme.

Chlorpromazine does not mix well with some other medicines

Tell your doctor or pharmacist before you take chlorpromazine if you are taking any other medicines, as they may need to change your dose of chlorpromazine:

If you have any further questions about this, you should speak to your doctor or pharmacist.

Always tell the doctor if you are taking other medicines.

Tell the pharmacist you are taking chlorpromazine if you buy medicines (including things you put on your skin) for common illnesses.

Get your weight, height, waist circumference and blood checked regularly when you start chlorpromazine

  • Young people who take antipsychotic medicines should have some regular checks while taking these medicines
  • When you begin the treatment, the doctor should take a note of your weight, waist measurement and height and blood pressure
  • They should also do blood tests to check your liver, blood sugar, and some hormones like prolactin
  • They may check how young women are doing with their periods as the prolactin hormone can affect these
  • They may even do a heart machine test called an ECG (electrocardiogram) if you are at risk of heart disease

These tests should be done again regularly, especially during the first few weeks of your treatment. After that they should be done every year.

Be careful if you are also using street drugs

  • Antipsychotics block the effect of dopamine, so this means the ‘high’ may not be as ‘high’ as before from any street drug.
  • You may be tempted to increase your dose of the street drug to make up for it, but this could be dangerous.

Stopping the medication causes the balance of chemicals in the brain to alter

  • Once you start taking an antipsychotic, the brain adjusts to having a new level of dopamine around.
  • If you stop taking the antipsychotic all at once, the balance starts to change again. You could get your old symptoms back.
  • People usually take chlorpromazine for a long time, to keep those symptoms away.

Stopping this medicine quickly, or reducing the dose too much at once, may cause your old symptoms to come back or give you kick back. You can stop taking it safely with your doctor’s help

  • You may get your old symptoms back, or get kick back, if you stop chlorpromazine suddenly.
  • It is better to agree stopping with a doctor who can advise you on a gradual reduction.
  • The best way to stop chlorpromazine is to slowly reduce the dose over several days or longer before stopping.
  • If chlorpromazine is stopped suddenly, it can cause some unpleasant kick back symptoms like feeling sick, being sick, shaking, uncontrolled movements of the hands and body, and having difficulty getting to sleep.

Reference sources

Search www.medicines.org.uk to find patient information leaflets and prescribing information on chlorpromazine. Tablets, liquid and injection are listed separately. The SmPC lists all the inactive ingredients in the product so you can check against any allergies. If you are still unsure about this then speak to your pharmacist.

British National Formulary (BNF) and British National Formulary for children. Download the BNF/BNFC app (blue background) on to your mobile device. No longer available for public access via the web

  • Taylor D, Barnes T, Young A. Maudsley Prescribing Guidelines in Psychiatry, 13th edition. Oxford: John Wiley & Sons, May 2018. ISBN: 978-1-119-44260-8
  • Royal Pharmaceutical Society. Medicines Ethics and Practice (42nd edition). London: RPS, 2018. Standards for pharmacists to work to. It is not a free publication
  • World Anti Doping Agency WADA Prohibited List https://www.wada-ama.org/en/resources/science-medicine/prohibited-list-documents
  • Choiceandmedication; an independent source of information on many mental health conditions and their medicines with easy to read fact sheets www.choiceandmedication.org Personal subscriptions to download the app available for £1 per month (with proportionate discounts for longer periods) but your local mental health Trust may subscribe and provide information sheets for free.
  • Best Use of Medicines in Pregnancy (BUMPS). Information sheets on drugs in pregnancy http://www.medicinesinpregnancy.org/
  • Drugs and Lactation Database (LactMed). Information on drugs in breastfeeding https://toxnet.nlm.nih.gov/newtoxnet/lactmed.htm 
Stop taking medsStop taking Chlorpromazine and go to a doctor or hospital straight away if you get any of the following symptoms:
  • Difficulty in swallowing, or any other symptoms like swelling in the mouth, tongue, face and throat, itching, rash, that could be an allergic reaction to the medicine
  • Muscles going stiff or rigid with high fever, sweating, looking pale, feeling strange and fainting or losing consciousness, or very rapid or irregular heartbeat (tachycardia) – this may be a serious and life-threatening side-effect called neuroleptic malignant syndrome
  • If a man gets a painful erection that lasts for a long time
  • Skin reactions – rashes, flaking of the skin or red blisters on the skin
  • The whites of your eyes and skin become yellow in colour – this could be jaundice – look out for this especially in the first month of taking the medicine
Dont stop taking medsGo to your doctor or the hospital straight away, but don't stop taking Chlorpromazine if you get any of the following symptoms:
  • Swelling, pain or redness in the leg, or chest pain and difficulty breathing – this may be due to a blood clot
  • Fast or unusual heartbeat, or chest pain round the heart that spreads to the shoulders, neck or arms with difficulty breathing (possible heart attack) 

Do not stop your medicine, but see a doctor as soon as possible if you get any of the following symptoms:

  • Feeling down (depressed), agitated or not feeling any emotion about things
  • Having fits (seizures)
  • High temperature, chills and ulcers in your mouth and throat, sore throat and unusual tiredness – these can be a sign of problems in the blood that needs a test
  • Feeling dizzy when you stand up (low blood pressure)
  • Feeling very thirsty or wanting to go and pee a lot (high blood sugar)
  • Low body temperature
  • Finding it hard to go for a poo, or a change in the times when you do this.