Do ticagrelor and clopidogrel have the same antiplatelet effect? ​​What are the differences?

When preventing and treating cardiovascular and cerebrovascular diseases, antiplatelet therapy is a very important part. It can prevent platelets from aggregating and forming blood clots, and prevent the occurrence of myocardial infarction and cerebral infarction. In addition to the classic aspirin, the commonly used drugs for antiplatelet therapy include clopidogrel and ticagrelor.

In terms of drug action mechanism, both clopidogrel and ticagrelor act on the P2Y12 receptor on platelets. So a friend asked Huazi, since the two drugs have the same action mechanism, are they the same in terms of efficacy? What is the difference?

1. Both are P2Y12 receptor antagonists. Clopidogrel and ticagrelor are P2Y12 receptor antagonists, which can inhibit the binding of adenosine diphosphate (ADP) to the P2Y12 receptor on platelets, thereby inhibiting ADP-mediated platelet aggregation, preventing the formation of blood clots, and exerting a protective effect on cardiovascular and cerebrovascular systems.

Clopidogrel and ticagrelor have the same point of action, so their antiplatelet effects are similar. They can be used in combination with aspirin to form a "dual-antiplatelet" treatment plan, which is often used in the treatment of acute coronary syndrome, heart stents, and heart bypass. Both can replace aspirin for the prevention and treatment of cardiovascular and cerebrovascular diseases in those who cannot tolerate aspirin.

2. What is the difference between the two mechanisms of action? The two drugs have the same mechanism of action, but in terms of onset time, ticagrelor is faster than clopidogrel. Therefore, for patients with acute coronary syndrome, when rapid inhibition of platelet aggregation is required, if there are contraindications to aspirin, ticagrelor can be given priority.

The binding of clopidogrel to the platelet P2Y12 receptor is irreversible, so taking it once a day can produce a continuous antiplatelet effect. However, the binding of ticagrelor to the platelet P2Y12 receptor is reversible, and the half-life of blood drug concentration is about 7 hours, so it needs to be taken twice a day to have an antiplatelet effect, and the medication compliance is poor.

3. Which has a stronger antiplatelet effect? ​​Related studies have shown that the antiplatelet effect of ticagrelor is stronger than that of clopidogrel. When preventing cardiovascular diseases, such as myocardial infarction, ticagrelor is more effective; when preventing cerebrovascular diseases, such as stroke, the two have similar effects and no obvious difference.

Because ticagrelor has a stronger antiplatelet function, the risk of bleeding is slightly higher than clopidogrel, but the incidence of bleeding caused by the two is similar. Considering the antiplatelet effect and the incidence of adverse reactions, ticagrelor is the preferred choice. If ticagrelor cannot be tolerated, clopidogrel can be chosen.

4. The two are different in terms of usage restrictions. The coagulation function of the elderly is weakened and the risk of bleeding increases. For the elderly population over 75 years old, if "dual anti" treatment is required, it is recommended to use clopidogrel, which has a lower bleeding risk, in combination with aspirin.

Antiplatelet drugs may cause gastrointestinal damage. People at high risk of gastrointestinal diseases can use proton pump inhibitors ("prazole" drugs) for prevention. However, it should be noted that clopidogrel is a prodrug and needs to be metabolized by the CYP2C19 enzyme to exert its efficacy. Omeprazole and esomeprazole will inhibit the CYP2C19 enzyme, reducing the efficacy of clopidogrel, so they should be avoided. Other proton pump inhibitors such as rabeprazole and pantoprazole can be selected.

Ticagrelor is mainly metabolized by CYP3A4 enzyme, so drugs with enzyme inhibitory effects such as ketoconazole, itraconazole, voriconazole, and clarithromycin; and drugs with enzyme inducing effects such as phenytoin sodium, phenobarbital, and carbamazepine should not be used in combination with ticagrelor.

For people with renal insufficiency, the probability of increased creatinine and the incidence of kidney-related adverse events when using ticagrelor are higher than those using clopidogrel. Therefore, clopidogrel is recommended for people with renal insufficiency.

The metabolites of ticagrelor can interfere with uric acid metabolism and may induce gout. Therefore, people with hyperuricemia are recommended to use clopidogrel.

To sum up, in antiplatelet therapy, ticagrelor is more effective than clopidogrel and is preferred, but it needs to be taken twice a day, and compliance is poor. Clopidogrel is more suitable for the elderly, people with renal insufficiency, and gout, and has fewer side effects. The drug must be used under the guidance of a doctor. If you have any questions about the medication, please consult a doctor or pharmacist in time. I am pharmacist Huazi, welcome to follow me and share more health knowledge.