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Sulfadiazine tablets

Sulfadiazine is prescribed to prevent episodes of rheumatic fever.

It is a sulfonamide antibiotic. Tell your doctor before taking the tablets if you have ever had an allergic reaction to any other sulfonamide (this includes any reaction to co-trimoxazole or the brand Septrin®).

It is important for you to drink plenty of water while you are on sulfadiazine.

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About sulfadiazine

Type of medicine

A sulfonamide antibiotic

Used for

Preventing episodes of rheumatic fever

Available as


Sulfadiazine is a type of antibiotic called a sulfonamide. Although sulfonamide antibiotics are rarely prescribed nowadays, sulfadiazine remains a useful medicine to help prevent recurrent episodes of rheumatic fever.

Rheumatic fever is an inflammatory disease which used to be fairly common amongst children in the UK, but now occurs rarely. It develops following an infection with a type of germ (bacterium) called streptococcus, and it can cause serious damage to the heart. There is a risk that further episodes will occur after the first episode, so antibiotics like sulfadiazine are prescribed long-term to help prevent this.

Sulfadiazine is also an ingredient in an antiseptic cream, usually used for burns or skin ulcers. For more information see our leaflet Silver sulfadiazine cream for skin infections (Flamazine).

Occasionally sulfadiazine is prescribed for other reasons but these are not covered by the information presented here. If you have been prescribed sulfadiazine tablets for a condition other than rheumatic fever, ask your doctor if you have any questions about your treatment.

Before taking sulfadiazine

Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you (or your child) start taking sulfadiazine it is important that your doctor knows:

  • If you are pregnant or breastfeeding.

  • If you/they have any problems with the way the kidneys work, or any problems with the way the liver works.

  • If you/they have a blood disorder, especially if it is a rare inherited blood disorder called porphyria.

  • If you/they have asthma.

  • If you/they have an enzyme deficiency called G6PD deficiency.

  • If you/they have low amounts of the vitamin folic acid.

  • If you/they are taking any other medicines. This includes any medicines taken which are available to buy without a prescription, as well as herbal and complementary medicines.

  • If you/they have ever had an allergic reaction to a medicine. It is particularly important that you tell your doctor if there has ever been a bad reaction to a sulfonamide antibiotic, such as co-trimoxazole (brand name Septrin®).

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How to take sulfadiazine

  • Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about sulfadiazine, and it will also provide you with a full list of the side-effects which you could experience from taking it.

  • Take sulfadiazine tablets exactly as your doctor tells you to. As a guide, it is usual for adults and older children to take two 500 mg tablets daily, whereas children weighing less than 30 kilograms are usually prescribed one 500 mg tablet to take each day. The dose prescribed will be printed on the label of the pack of tablets to remind you about what the doctor said to you.

  • Try to take the tablets at the same time of day each day, as this will help you to remember to take sulfadiazine regularly. You can take the tablets either with or without food.

  • Have plenty to drink as you take the tablets (at least half a glassful of water), and drink several large glasses of water throughout the day. Aim to drink 2-3 litres of fluid every day. This will help to prevent the sulfadiazine from forming crystals in your urine.

  • If you forget to take a dose at your usual time, take it as soon as you remember. If you do not remember until the following day, leave out the missed dose. Do not take two doses together to make up for a forgotten dose.

Getting the most from your treatment

  • Your doctor will ask to see you on a regular basis so that your progress can be monitored. Try to keep these appointments, as you will need to have regular blood tests.

  • It is likely that you will be prescribed sulfadiazine to take for a number of years, so continue to take the tablets regularly until you are told otherwise by your doctor.

  • If you are due to have an operation or any dental treatment, tell the person carrying out the treatment which medicines you are taking. This is important because sulfadiazine can interfere with some anaesthetics.

  • This antibiotic could stop the oral typhoid vaccine from working properly. If you are due to have any vaccinations, make sure the person treating you knows that you are taking it.

  • If you buy any medicines 'over the counter', always check with a pharmacist that they are suitable for you to take. For example, medicines containing aspirin (available as painkillers and 'common cold' remedies) could increase the risk of side-effects from sulfadiazine and are probably best avoided.

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Can sulfadiazine cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with sulfadiazine. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.


sulfadiazine side-effects

What can I do if I experience this?

Feeling sick (nausea) or being sick (vomiting), loss of appetite

Stick to simple foods - avoid fatty or spicy meals. Try taking the tablets with something to eat if you are not already doing so


Drink plenty of water to replace any lost fluids. If the diarrhoea becomes severe, or contains blood, let your doctor know



Drink plenty of water and ask your pharmacist to recommend a suitable painkiller. If the headaches continue, speak with your doctor

Rash, low back pain

Let your doctor know

Important: if you experience any of the following rare but serious symptoms, speak with your doctor immediately or go to your local accident and emergency department without delay.

  • An allergic reaction such as swelling of the mouth, face, tongue or throat, or any difficulty breathing.

  • Severe itchy skin rash with blisters.

  • High temperature (fever) with a sore throat, mouth ulcers or unusual bruising or bleeding.

  • Headache, high temperature fever, stiff neck, tiredness, feeling ill and an increased sensitivity to bright light.

If you experience any other symptoms which you think may be due to the tablets, speak with your doctor or pharmacist for further advice.

How to store sulfadiazine

  • Keep all medicines out of the reach and sight of children.

  • Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

Important information about all medicines

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article History

The information on this page is written and peer reviewed by qualified clinicians.

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