Quinidine is used to treat abnormal heart rhythm. This medicine may also be used to treat malaria.
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.
This medicine should be taken with food or milk to decrease stomach discomfort. Try to take it at the same time each day.
Quinidine is available as a conventional tablet and extended-release tablet.
If you are taking the extended-release type of tablet, swallow it whole. Do not chew or crush the tablet. Extended release tablets may be broken and split in half only if necessary.
This medicine must be taken regularly for it to be effective. Continue taking Quinidine 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.
Alert your doctor if you have any of these conditions:
- complete heart block without a pacemaker (artificial device for regulating heartbeat)
- history of blood disorder (e.g. excessive bruising and bleeding) developed during prior treatment with quinidine and related drugs such as quinine
- myasthenia gravis (muscle weakness disorder)
as this medicine may not be suitable for you.
Inform your doctor if you have the following conditions:
- heart failure
- G6PD deficiency (an inherited blood disorder that affects the red blood cell)
- liver disease
- kidney disease
Let your doctor know if you are pregnant or breastfeeding.
For as long as you are taking this medicine, you may need to have regular blood tests(e.g. complete blood count, liver and kidney function tests) to check your body's response to the medicine. Your doctor will advise you about how often you need to have blood tests.
Quinidine may cause any of the following side effects: stomach discomfort, nausea, vomiting, diarrhoea, rash, light headedness, chest pain, palpitations, headache, tiredness and weakness.
Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
- blurred vision, ringing in the ears
- yellowing of the skin or eyes
- unusual bleeding or bruising
- new or worsened abnormal heart rhythm
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:
- other medicines used to treat abnormal heart rhythm e.g. amiodarone, verapamil
- medicines for TB (lung infection known as tuberculosis) e.g rifampicin
- antibiotics e.g. clarithromycin, erythromycin
- medicines for fungal infections e.g. ketoconazole, itraconazole
- medicines for epilepsy (fits or seizure) e.g. phenobarbital, phenytoin
- medicines for heart disease and high blood pressure e.g. propranolol, digoxin, nifedipine
- medicines for myasthenia gravis (muscle weakness disorder) e.g. pyridostigmine, neostigmine
- 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 and excessive consumption (more than 1 litre a day) of grapefruit juice.
Store in a cool, dry place away from the reach of children.
Medicines must not be used past the expiry date.