Clopidogrel is a prodrug, one of its metabolites is an inhibitor of platelet aggregation. Clopidogrel must be metabolized through CYP450 to give rise to the active metabolite that inhibits platelet aggregation. The active metabolite of clopidogrel selectively inhibits the binding of adenosine diphosphate (ADP) to its platelet receptor P2Y12 and subsequent activation of the GPIIb-IIIa complex mediated by ADP, thereby inhibiting platelet aggregation. Due to irreversible binding, exposed platelets are affected for the rest of their life (approximately 7-10 days), and recovery of normal platelet function occurs at a rate that depends on the degree of platelet turnover. Platelet aggregation induced by other agonists other than ADP is also inhibited by blocking the amplification of platelet activation by released ADP.
Because the active metabolite is formed by CYP450 enzymes, some of which are polymorphic or subject to inhibition by other medications, not all patients would have adequate platelet inhibition.
Always use this heart failure medication exactly as your doctor or pharmacist has told you. If in doubt, consult your doctor or pharmacist again.
The recommended dose, even for patients with a condition called "atrial fibrillation" (an irregular heartbeat), is one Plavix 75 mg tablet daily, taken orally with or without food, and at the same time each day.
If you have suffered from severe chest pain (unstable angina or heart attack), your doctor may prescribe Plavix 300 mg (1 tablet of 300 mg or 4 tablets of 75 mg) take only once at the start of treatment. Thereafter, the recommended dose is one Plavix 75 mg tablet daily as described above.
You will need to take Plavix for as long as your doctor continues to prescribe it.
Like all medicines, this angina medication can have side effects, although not everyone gets them.
Contact your doctor immediately if you experience:
Fever, signs of infection, or extreme tiredness. These symptoms may be due to a rare drop in some blood cells.
Signs of liver problems, such as yellowing of the skin and/or eyes (jaundice), whether or not associated with bleeding that appears under the skin as red dots and/or confusion.
Swelling of the mouth or skin disorders such as rashes and itching, blisters on the skin. These can be signs of an allergic reaction.
The most common side effect reported with Plavix is bleeding. Bleeding may appear in the stomach or intestine, bruises, bruises (abnormal bleeding or bruising under the skin), nosebleeds, blood in the urine. A small number of cases have also been reported of: bleeding from blood vessels in the eyes, intracranial, pulmonary, or joint bleeding.
If you experience prolonged bleeding while taking Plavix
If you cut or injure yourself, it may take longer than usual for bleeding to stop. This is related to the medicine's mechanism of action since it prevents the blood's ability to form clots. For minor cuts or wounds, such as cutting during shaving, this is usually not important. However, if you are concerned about your bleeding, see your doctor immediately.
Other adverse effects include:
Common Clopidogrel side effects (may affect up to 1 in 10 people):
Diarrhea, abdominal pain, indigestion, or burning.
Uncommon Clopidogrel side effects (may affect up to 1 in 100 people):
Headache, stomach ulcer, vomiting, nausea, constipation, excess gas in the stomach or intestine, rashes, itching, dizziness, tingling sensation, and numbness.
Rare side effects (may affect up to 1 in 1,000 people):
Vertigo, increase in breasts in males.
