Quinidine is used to treat abnormal heart rhythm.
This medicine may be used to treat other conditions as decided by your doctor.
Take Quinidine 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.
You may take this medicine with food or milk to reduce any stomach discomfort that it may cause. Try to take it at the same time each day.
This medicine is available as a conventional or extended-release tablet.
If you are taking the extended-release type of tablet (usually labelled as "ER"), swallow it whole. Do not chew or crush the tablet. Extended-release tablets may be broken and split in half only if necessary.
Quinidine must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed by the doctor.
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.
Do not take Quinidine if you ever had an allergic reaction (e.g. rashes, breathlessness, swollen eyes) to this medicine or any of its ingredients.
Alert your doctor if you have the following conditions:
- history of immune thrombocytopenia (blood disorder caused by decrease number of platelets leading to excessive bleeding, easy bruising and multiple tiny red or purplish spots on the skin or the insides of the mouth)
- heart block greater than 1st degree
- delay in conduction (signals that controls the heartbeat)
- myasthenia gravis (muscle weakness disorder)
As Quinidine may not be suitable for you.
Inform your doctor if you have the following conditions:
- other heart problems e.g. abnormally fast and erratic heartbeats
- hypokalaemia (low potassium level in the blood)
- hypomagnesaemia (low magnesium level in the blood)
- G6PD deficiency (an inherited blood disorder where the body lacks a certain enzyme necessary for the proper functioning of red blood cells)
- kidney disease
- liver disease
Let your doctor know if you are pregnant or breastfeeding.
Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly. Routine tests (e.g. complete blood count, heart, liver and kidney function) may be done while you are being treated with this medicine. Your doctor will advise you about how often you need to have these tests.
Quinidine may cause any of the following side effects: diarrhoea, nausea, vomiting, dizziness, headache, and tiredness.
Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
- rashes, breathlessness, swelling of the face, eyes or mouth
- fast or irregular heartbeat
- yellowing of the skin or eyes, abdominal pain, dark coloured urine, tiredness, swelling in the legs and ankles
- severe rashes, especially with multiple tiny red or purple spots on the skin and sometimes on the inside of the mouth
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 heart disease or high blood pressure e.g. verapamil, diltiazem, digoxin
- medicines for glaucoma (increased pressure in the eye)
- water pills or medicines for water retention
- medicines for epilepsy (fits or seizures) e.g. phenytoin, phenobarbital
- medicines used for blocking pain and sensation, and relaxing the muscles during procedures e.g. succinylcholine, tubocuraraine, pancuronium
- rifampicin (medicine to treat TB, a lung infection known as tuberculosis)
- cimetidine (medicine that reduces stomach acid production)
- ketoconazole (medicine to treat fungal infection)
- warfarin (blood-thinning medicine)
This list does not include all medicines that may interact with Quinidine.
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.
Avoid alcohol.
Avoid excessive consumption of grapefruit or grapefruit juice (more than 1 litre a day).
Store in a cool, dry place away from the reach of children.
Protect from light.
Medicines must not be used past the expiry date.
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