What Are the Most Common Clopidogrel Interactions?

An antiplatelet medication, clopidogrel is generally taken by people who have suffered a heart attack, stroke or other clotting event and by people who are at high risk for clots. The medication effectively reduces the body’s capacity to form clots by partially inhibiting platelet function. An enzyme metabolizes the drug to its active form following ingestion. In cases where this enzyme is defective, a personalized clopidogrel dosage is necessary to avoid side effects. The use of certain medications that are also metabolized by this enzyme can lead to several common clopidogrel drug interactions, including an increased risk of blood clots and a risk of bleeding from the gastrointestinal tract.

Medications such as clopidogrel are widely used to prevent further clotting events in people who have already suffered a heart attack or stroke. People who have not clotted before but are at high risk for clots might also use the drug. To achieve the inhibition of platelet function that results in the drug’s therapeutic effect, clopidogrel must first be metabolized to its active form in the body. This process is directly linked to the function of CYP2C19, an enzyme that is responsible for the metabolism of several medications. Subnormal or poor CYP2C19 enzyme activity is not uncommon and might lead to increased risk of side effects and drug interactions.

People who have severe or mild defects in the metabolic activity of enzyme CYP219 should be aware that the simultaneous use of clopidogrel with other medications metabolized by this enzyme can lead to serious clopidogrel interactions. Proton pump inhibitors, such as lansoprazole, are a class of medications that typically are used by people who have severe acid reflux, gastritis or stomach ulcers. The most common clopidogrel interactions are seen in patients who use any type of proton pump inhibitor medications together with clopidogrel. The intake of proton pump inhibitors within 12 hours of taking clopidogrel greatly reduces platelet inhibition. This increases the risk of clot formation.

The simultaneous use of clopidogrel and nonsteroidal anti-inflammatory medications can also result in clopidogrel interactions in the form of increased bleeding risk from the gastrointestinal tract. The possibility of drug interactions does not abate even when the medications are taken several hours apart. People who are on treatment with clopidogrel should not take aspirin or other antiplatelet medications without consulting a healthcare professional, because the drugs’ cumulative action might greatly increase the potential for bleeding episodes because of clopidogrel interactions.

Scientific studies indicate that there is a possibility for clopidogrel interactions with selective serotonin reuptake inhibitors (SSRI), a class of antidepressant medications. Concurrent use of SSRIs with clopidogrel is thought to be associated with a small increase in bleeding risk. This is generally thought to be one of the most common clopidogrel interactions.