Diltiazem is used on its own or together with other medicines to help keep your blood pressure under control. It relaxes your blood vessels and this helps to lower your blood pressure.
This medicine is also used to treat chest pain (angina pectoris).
Diltiazem may be used to treat other conditions as decided by your doctor.
Take Diltiazem 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.
Ask your doctor or pharmacist about whether you should take this medicine with or without food. Different brands of Diltiazem may be taken differently. Try to take it at the same time each day.
Diltiazem is available as a conventional tablet or modified-release tablet or capsule.
If you are taking the conventional tablet, swallow it whole with a glass of water.
If you are taking the modified-release type of tablet or capsule (usually labelled as "LA", "SR", "CD", "XL", or "Retard"), swallow it whole. Do not divide, chew, or crush the tablet or capsule.
The dose of this medicine will be decided by your doctor. Your doctor will advise you on the treatment timeframe depending on your condition and response to the medication.
Diltiazem 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.
Alert your doctor if you have the following conditions:
- abnormal heart rhythm or 2nd- to 3rd-degree heart block without a functioning pacemaker
- very slow heartbeat (less than 50 beats per minute)
- recent heart attack and have a fluid build-up in the lungs
- heart failure (weakness and inability of the heart to pump blood)
- low blood pressure (systolic that is less than 90 mmHg)
as Diltiazem may not be suitable for you.
Do not breastfeed while you are being treated with this medicine.
Do not take Diltiazem with a medicine used for heart failure called ivabradine.
Inform your doctor if you have the following conditions:
- other heart problems e.g. 1st-degree heart block, impaired left ventricular function, slow heartbeat
- risk of bowel blockage
- kidney disease
- liver disease
Let your doctor know if you are pregnant.
Be sure to check with your doctor or pharmacist before giving Diltiazem to an elderly. Elderly people may be more sensitive to the side effects.
If you are going to have a procedure involving ionic contrast agents or an operation, including minor surgery and dental work, inform your doctor or dentist that you are taking this medicine.
Why is it important to keep my appointments with the doctor?
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. liver and kidney function, heart rate, ECG [a test to record the electrical activity of the heart]) 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.
- Your blood pressure may fall to unsafe levels without you noticing it. Monitor your blood pressure during treatment.
What lifestyle changes can I make to improve my blood pressure?
Regular exercise and eating a healthy diet will help control your blood pressure and improve your overall health. Engage in physical activity like walking for at least 30 to 60 minutes on most days of the week. If you have not exercised for a long time, start with light exercises such as slow walks. Speak to your doctor about what type of exercise would be suitable for you. Follow a healthy diet plan by eating more fruits, vegetables, whole grains and low-fat dairy products and reduce your intake of foods high in saturated fat, cholesterol and sodium. Cutting down on deep-fried foods and using less salt when cooking can kick-start your healthy diet.
If you smoke, you should try to quit. Smoking is harmful to your blood pressure, heart and overall health. Speak to your doctor or pharmacist about ways to stop your smoking habit.
Diltiazem may cause any of the following side effects: headache, dizziness, nausea, indigestion, constipation, vomiting, diarrhoea, nervousness, and difficulty sleeping.
Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
- slow or abnormal heartbeat
- severe dizziness or passing out
- unusual changes in mood or behaviour (being too depressed, agitated, or having compulsive and impulsive behaviour)
- yellowing of the skin or eyes, abdominal pain, dark coloured urine, tiredness, swelling in the legs and ankles
- rashes with peeling of the skin or blistering of the lips, mouth or eyes accompanied by fever
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Do not take Diltiazem with ivabradine (medicine for heart failure).
Inform your doctor and pharmacist if you are taking any of these medicines:
- medicines for irregular heartbeat e.g. amiodarone, digoxin, quinidine
- medicines for epilepsy (fits or seizure) e.g. carbamazepine, phenytoin
- medicines that can cause drowsiness or affect your concentration e.g. midazolam, triazolam
- cholesterol-lowering medicines e.g. simvastatin, atorvastatin
- ciclosporin (medicine used in organ transplant or certain immune disorders)
- theophylline (asthma medicine)
- methylprednisolone (anti-inflammatory medicine)
- buspirone (medicine for anxiety)
- cimetidine (medicine used to reduce stomach acid production)
- rifampicin (medicine to treat TB, infection known as tuberculosis)
- lithium (medicine for mood disorder)
This list does not include all medicines that may interact with Diltiazem.
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. Avoid excessive heat and humidity.
Medicines must not be used past the expiry date.
Sign Out
