Pyrimethamine is used together with other medicines for the treatment and prevention of malaria. It may also be used to treat certain infections caused by bacteria, parasites and fungi.
Take Pyrimethamine exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.
This medicine should be taken with food or immediately after a meal to minimise stomach discomfort.
Take Pyrimethamine at regular intervals for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed by the doctor.
Do not skip any doses. To clear the infection, you must complete the entire course of this medicine. If you don't, the infection will not clear completely.
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.
DO NOT double a dose under any circumstances.
If you often forget to take your medicine, let your doctor and pharmacist know.
Alert your doctor if you have a blood disorder called “megaloblastic anaemia”, as Pyrimethamine may not be suitable for you.
Inform your doctor if you have the following conditions:
- liver disease
- kidney disease
- epilepsy (fits or seizures)
- G6PD deficiency (an inherited blood disorder that affects the red blood cell)
Let your doctor know if you are pregnant or breastfeeding.
For as long as you are taking Pyrimethamine, you will need to have regular blood tests to check your body's response to the medicine. Your doctor will advise you about how often you need to have blood tests.
Your doctor may also give you some folic acid tablets to prevent blood disorders that may occur in people taking high doses of this medicine.
Pyrimethamine may cause dizziness. If affected, do not drive or take part in any activity in which you need to be alert.
Other side effects include any of the following: headache, stomach discomfort, nausea, vomiting and loss of appetite.
Some side effects my need immediate medical help. Alert your doctor quickly if you experience sore throat, pale appearance, bruising, shortness of breath, yellowing of the skin, inflammation or redness of the tongue.
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Inform your doctor and pharmacist if you are taking any of these medicines:
- medicines for epilepsy (fits or seizures) e.g. phenytoin
- antibiotics e.g. co-trimoxazole, sulfadiazine
- medicines for mood disorders e.g. lorazepam
- other medicines to treat malaria e.g. quinine
- medicines to treat viral infections e.g. zidovudine
- warfarin (blood-thinning medicine)
This list does not include all medicines that may interact with Pyrimethamine.
Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
Store in a cool, dry place away from the reach of children.
Medicines must not be used past the expiry date.