dipyridamole

Action and Spectrum

Actions and Spectrum:

The main action of dipyridamole is to inhibit the activity of the enzyme adenosine diphosphate (ADP) receptor on platelets, which is involved in the process of platelet aggregation. By inhibiting the ADP receptor, dipyridamole reduces the ability of platelets to stick together and form clots.

dipyridamole is used in the prevention of thromboembolic events (blood clots) such as stroke and myocardial infarction (heart attack), and also used to improve blood flow to the heart in people with coronary artery disease. It is usually used in combination with other antiplatelet medications such as aspirin.

The drug also has a vasodilator action, which means it widens the blood vessels and increases blood flow, which may improve blood flow to the heart and brain.

dipyridamole has a wide spectrum of use, it can be used in the treatment and prevention of a variety of cardiovascular conditions such as:

• Coronary artery disease
• Ischemic stroke
• Transient ischemic attack
• Peripheral artery disease
• Deep vein thrombosis
• Pulmonary embolism

Drug Interaction

Adverse Reaction

Frequency Defined 

>10% 

Angina exacerbation, IV (19.7%)

Chest pain (20%)

Abnormal ECG (15.9%)

Dizziness (12%)

Headache, IV (12.2%)

1-10%

Extrasystole (5%)

Abdominal discomfort, oral (6.1%)

Nausea, IV (4.6%)

Flushing (3.4%)

Hypotension, IV (4.6%)

ST-T changes (7.5%)

Black Box Warning

Black Box Warning

dipyridamole, a medication used to prevent blood clots, carries a “black box warning” for the risk of severe and potentially fatal bleeding.

Contraindication / Caution

Contraindication/Caution:

dipyridamole is a medication that is used to prevent blood clots and to increase blood flow to the heart. However, there are certain situations where the use of dipyridamole may be contraindicated or used with caution. These include:

Allergic reactions: Individuals who have had an allergic reaction to dipyridamole or any of its ingredients should not take the medication.

Hemorrhagic stroke: dipyridamole may increase the risk of bleeding in individuals who have had a hemorrhagic stroke.

Gastrointestinal bleeding: dipyridamole may increase the risk of bleeding in the stomach or intestines.

Hemorrhagic disease of the newborn: dipyridamole may increase the risk of bleeding in newborns with hemorrhagic disease.

Anemia: dipyridamole may decrease the number of red blood cells in the body, which can lead to anemia.

Kidney disease: dipyridamole may not be safe for individuals with kidney disease and may need to be used with caution.

Liver disease: dipyridamole may not be safe for individuals with liver disease and may need to be used with caution.

Pregnancy / Lactation

Pregnancy warnings:   

US FDA pregnancy category: B

Lactation:  

Excreted into human milk is known

Pregnancy Categories:        

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester.

Category B: There were lack of studies on pregnant women and no evidence of risk to the foetus in animal experiments.

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.

Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.

Category N: There is no data available for the drug under this category

Pharmacology

Pharmacology: 

dipyridamole is a vasodilator and antiplatelet agent that is used in a variety of medical conditions, including heart disease and stroke prevention. It works by inhibiting the uptake of adenosine by platelets and endothelial cells, which leads to an increase in the levels of intracellular cAMP and a reduction in platelet aggregation.

Pharmacodynamics: 

It works by inhibiting the activity of phosphodiesterase, an enzyme that is responsible for breaking down cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). These enzymes play a crucial role in the process of platelet aggregation, which is the clumping together of platelets in the blood that can lead to the formation of blood clots.

Pharmacokinetics:  

Absorption 

dipyridamole is absorbed rapidly and complete after oral administration.

Distribution 

It is widely distributed throughout the body, with high levels found in the liver, lung, and heart.

Metabolism 

dipyridamole is metabolized in the liver, mainly by the cytochrome P450 enzyme system.

Elimination and Excretion 

Most of the dipyridamole is excreted in the urine, primarily as metabolites, with a small portion excreted in the feces. The half-life of dipyridamole is about 2-4 hours.

Adminstartion

Administration: 

Oral/IV administration

dipyridamole is usually administered orally in tablet form. The dosage and frequency of administration will depend on the condition being treated and the patient’s individual response to the medication. It is important to follow the instructions provided by the healthcare provider and to not exceed the recommended dosage. dipyridamole may be taken with or without food, but it is recommended to take it with food to reduce stomach upset.

It is important to note that dipyridamole should not be abruptly discontinued as it may cause worsening of symptoms. The healthcare provider will determine the appropriate time to gradually decrease the dosage or stop the medication.

Patient Information Leaflet

Patient information leaflet

Generic Name: dipyridamole

Why do we use dipyridamole?

dipyridamole is a medication that is used to prevent blood clots from forming in the blood vessels. It works by inhibiting the action of certain enzymes that are involved in the formation of blood clots. dipyridamole is commonly used in combination with other medications, such as aspirin, to prevent blood clots in people who have a high risk of developing them, such as those who have had a previous heart attack or stroke.