Products
Clopidogrel is commercially available in tablet form (Plavix, generics). It has been approved in the United States since 1997 and in many countries and the EU since 1998. Clopidogrel is also combined with acetylsalicylic acid fixed (DuoPlavin).
Structure and properties
Clopidogrel (C16H16ClNO2S, Mr = 321.82 g/mol) is a thienopyridine derivative and a prodrug. It exists in the original as clopidogrel hydrogen sulfate, a white powder. Other salts, such as clopidogrel besylate and clopidogrel hydrochloride, are also used in generics.
Effects
Clopidogrel (ATC B01AC04) has antiplatelet properties. The effects are due to selective and irreversible inhibition of the P2Y12 receptor on platelets. This inhibits ADP (adenosine diphosphate) binding and subsequent activation. Clopidogrel inhibits platelets throughout their 7- to 10-day life span. It has a short half-life of 6 hours.
Indications
For secondary prevention of atherothrombotic events in adults, for example, after myocardial infarction, after stroke, or in acute coronary syndrome. Clopidogrel is also combined with acetylsalicylic acid.
Dosage
According to the drug label. Tablets are taken once daily, regardless of meals.
Contraindications
- Hypersensitivity
- Organ lesions with bleeding tendency, for example, active gastrointestinal ulcers, acute hemorrhagic stroke
- Severe hepatic insufficiency
- Hemorrhagic diathesis
For complete precautions, see the drug label.
Interactions
Clopidogrel is a substrate of CYP450 isozymes and of P-glycoprotein. The active metabolite is formed mainly by CYP2C19, with the involvement of CYP1A2, CYP2B6, and CYP3A4. When CYP2C19 is inhibited (e.g., by the PPI omeprazole) or when there are pharmacogenetic differences (poor metabolizers), the pharmacologic effect of clopidogrel may be reduced. Other drugs at risk for bleeding should be combined only with caution.
Adverse Effects
The most common potential adverse effects include bleeding, gastrointestinal symptoms (dyspepsia, abdominal pain, diarrhea), and skin rash.
