Dipantin

Indications

Dipyridamole is an antiplatelet medicine (it makes platelets less sticky). It is used:

• Together with low-dose Aspirin to lower the risk of another stroke in people who have had an ischaemic stroke or transient ischaemic attack (mini-stroke)
• Together with Warfarin or other anticoagulants to help prevent blood clots on artificial heart valves
• As an injection in hospital during heart scans (stress testing) in people who cannot exercise

How It Works

Dipyridamole raises the levels of adenosine and cyclic AMP in platelets and blood vessel walls. This makes platelets less likely to clump together and form clots, and it also widens small blood vessels, especially in the heart.

Dosage and Administration

Take exactly as prescribed. A common regimen for stroke prevention is the modified-release 200 mg capsule (often combined with Aspirin 25 mg) twice daily, morning and evening; swallow whole without chewing. Ordinary tablets for heart valve patients are usually 300 to 600 mg a day in 3 to 4 divided doses, taken before meals. Headache is common in the first weeks; your doctor may start with a lower dose. The injection is given only by a doctor or nurse.

Interactions

Dipyridamole strongly increases the effect of Adenosine; if you take dipyridamole, tell the doctor before any heart scan or treatment with adenosine. It adds to the bleeding risk of Warfarin, Heparin, Clopidogrel and NSAIDs. It may reduce the effect of cholinesterase inhibitors used in myasthenia gravis (such as Pyridostigmine) and can add to the effect of blood pressure medicines. Antacids may reduce absorption.

Contraindications

Do not take it if you are allergic to dipyridamole. Combination capsules with aspirin are not used in people with aspirin allergy, active stomach ulcer or bleeding disorders, or in children.

Side Effects

Common side effects include:

• Headache, often throbbing, especially in the first weeks
• Dizziness, flushing and low blood pressure
• Nausea, indigestion, diarrhoea and stomach pain
• Muscle aches

Less often, chest pain may worsen in people with severe coronary heart disease, and bleeding may increase, especially with other blood thinners.

Get urgent medical help if you have chest pain, fainting, signs of bleeding (black stools, vomiting blood, blood in the urine, unusual bruising), a severe headache with weakness or confusion, or signs of a serious allergic reaction.

Pregnancy and Lactation

It should be used in pregnancy only if clearly needed and prescribed by a doctor. Small amounts pass into breast milk; use during breastfeeding only if the doctor considers it necessary. Combination products with aspirin are generally avoided in late pregnancy.

Precautions and Warnings

Use with caution in severe coronary artery disease, unstable angina, recent heart attack, aortic stenosis, heart failure, low blood pressure, myasthenia gravis and bleeding disorders. Stop or adjust it only on medical advice, and tell any doctor, dentist or surgeon that you take it before procedures.

Overdose

Overdose may cause a warm feeling, flushing, sweating, restlessness, weakness, dizziness, low blood pressure and fast heartbeat, and possibly chest pain. Seek emergency medical help.

Therapeutic Class

Antiplatelet agent; phosphodiesterase inhibitor and adenosine reuptake inhibitor.

Storage

Store below 30°C in a dry place, away from light and out of the reach of children. Keep modified-release capsules in their original container to protect from moisture.