Clopidogrel Side Effects

Medically reviewed by Drugs.com. Last updated on Dec 11, 2024.

Applies to clopidogrel: oral tablet.

Important warnings This medicine can cause some serious health issues

Oral route (tablet)

The effectiveness of clopidogrel hydrogen sulfate results from its antiplatelet activity, which is dependent on its conversion to an active metabolite by the cytochrome P450 (CYP) system, principally CYP2C19.

Clopidogrel hydrogen sulfate at recommended doses forms less of the active metabolite and so has a reduced effect on platelet activity in patients who are homozygous for nonfunctional alleles of the CYP2C19 gene, (termed “CYP2C19 poor metabolizers”).

Tests are available to identify patients who are CYP2C19 poor metabolizers.

Consider use of another platelet P2Y12 inhibitor in patients identified as CYP2C19 poor metabolizers.

Serious side effects of clopidogrel

Along with its needed effects, clopidogrel may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking clopidogrel:

More common side effects

• collection of blood under the skin
• deep, dark purple bruise
• itching, pain, redness, or swelling

Less common side effects

• bloody nose
• bloody, black, or tarry stools
• vomiting of blood or material that looks like coffee grounds

Rare side effects

• bleeding in the eye
• confusion
• headache, sudden, severe, and continuing
• nausea and vomiting

Incidence not known

• anxiety
• blistering, peeling, loosening of the skin
• bloating
• blurred vision
• burning upper stomach pain
• change in mental status
• chest pain or tightness
• cold sweats
• coma
• constipation
• cool, pale skin
• cough or hoarseness
• dark or bloody urine
• difficulty in breathing or swallowing
• difficulty speaking
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• fast heartbeat
• feeling of discomfort
• fever with or without chills
• general feeling of tiredness or weakness
• hives, itching, skin rash
• increased hunger
• indigestion
• inflammation of the joints
• joint or muscle pain
• large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, sex organs
• light-colored stools
• loss of appetite
• lower back or side pain
• muscle aches
• nervousness
• nightmares
• noisy breathing
• painful or difficult urination
• pains in the side, possibly radiating to the back
• pinpoint red spots on the skin
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• rash with flat lesions or small raised lesions on the skin
• rectal bleeding
• red irritated eyes
• red skin lesions, often with a purple center
• reddening of the skin, especially around the ears
• seizures
• shakiness
• skin blisters
• slurred speech
• sore throat
• sores, ulcers, or white spots on the lips or in the mouth
• stomach cramps, tenderness, or pain
• sweating
• swelling of the eyes, face, or inside of the nose
• swelling or inflammation of the mouth
• swollen or painful glands
• trouble breathing
• unusual bleeding or bruising
• watery or bloody diarrhea
• yellow eyes or skin

Other side effects of clopidogrel

Some side effects of clopidogrel may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

• change in taste bad unusual or unpleasant (after) taste
• difficulty in moving
• loss of sense of taste
• muscle aches, cramps, or stiffness
• redness or swollen joints
• seeing, hearing, or feeling things that are not there

For healthcare professionals

Applies to clopidogrel: oral tablet.

General adverse events

The most commonly reported adverse effect was bleeding, including life threatening and fatal bleeding.^[Ref]

Hematologic

• Uncommon (0.1% to 1%): Fatal bleeding, eosinophilia, leucopenia, increased bleeding time, thrombocytopenia
• Rare (0.01% to 0.1%): Neutropenia
• Very rare (less than 0.01%): Decreased platelet count
• Postmarketing reports: Serious cases of bleeding (mainly skin), hemarthrosis, hematoma, hemorrhage of operative wound, fatal hemorrhage (intracranial, gastrointestinal, and retroperitoneal), thrombotic thrombocytopenic purpura (TTP), acquired hemophilia A, aplastic anemia, pancytopenia, agranulocytosis, granulocytopenia, anemia^[Ref]

In the COMMIT study (n=45,852), the incidence of major non-cerebral or cerebral bleeding was 0.6% in clopidogrel plus aspirin treated patients, with 0.4% classified as major non-cerebral (0.2% fatal) and 0.2% as hemorrhagic stroke (0.2% fatal). Non-major noncerebral bleeding or any noncerebral bleeding occurred in 3.6% and 3.9% of patients receiving this drug plus aspirin, respectively. Major bleeds were defined as cerebral bleeds or non-cerebral bleeds thought to have caused death or that required transfusion.

In the CURE study (n=12,562), the incidence of fatal bleeding (0.2%) and intracranial hemorrhage (0.1%) was the same between clopidogrel with aspirin and placebo with aspirin groups.^[Ref]

Gastrointestinal

• Common (1% to 10%): Abdominal pain, gastrointestinal hemorrhage, dyspepsia, diarrhea, nausea, gastritis
• Uncommon (0.1% to 1%): Vomiting, flatulence, constipation, gastric, peptic, or duodenal ulcer
• Rare (0.01% to 0.1%): Retroperitoneal hemorrhage
• Postmarketing reports: Colitis (ulcerative or lymphocytic), pancreatitis, stomatitis^[Ref]

In the CAPRIE study (n=19,185), gastrointestinal hemorrhage occurred in 2% of patients taking clopidogrel compared to 2.7% taking aspirin. Bleeding requiring hospitalization occurred in 0.7% clopidogrel-treated and 1.1% aspirin-treated patients.^[Ref]

Hypersensitivity

• Postmarketing reports: Angioedema, anaphylactic reactions, cross reactive hypersensitivity among thienopyridines (e.g. ticlopidine, prasugrel), hypersensitivity reactions^[Ref]

Cardiovascular

• Common (1% to 10%): Chest pain, hypertension, angina pectoris, coronary artery disorder, peripheral ischemia
• Very rare (less than 0.01%): Hematoma
• Postmarketing reports: Hypotension, syncope, vasculitis^[Ref]

Nervous system

• Common (1% to 10%): Dizziness, headache
• Uncommon (0.1% to 1%): Paresthesia
• Rare (0.01% to 0.1%): Vertigo, intracranial hemorrhage
• Postmarketing reports: Taste disturbances, ageusia^[Ref]

Musculoskeletal

• Common (1% to 10%): Arthralgia, back pain
• Postmarketing reports: Arthritis, myalgia, musculoskeletal bleeding^[Ref]

Psychiatric

• Common (1% to 10%): Depression
• Postmarketing reports: Hallucinations, confusion^[Ref]

Respiratory

• Common (1% to 10%): Upper respiratory tract infection, dyspnea, rhinitis, coughing, bronchitis, epistaxis
• Postmarketing reports: Bronchospasm, interstitial pneumonitis, eosinophilic pneumonia, respiratory tract bleeding (hemoptysis, pulmonary hemorrhage)^[Ref]

Dermatologic

• Common (1% to 10%): Rash, purpura, pruritus, bruising
• Postmarketing reports: Maculopapular, erythematous, or exfoliative rash, urticaria, bullous dermatitis, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, acute generalized exanthematous pustulosis, drug-induced hypersensitivity syndrome, drug rash with eosinophilia and systemic symptoms (DRESS), eczema, lichen planus^[Ref]

In CAPRIE (n=19,185), 4.2% of patients receiving clopidogrel developed a rash compared to 3.5% in the aspirin group. In CURE (n=12,562), 1.3% treated with clopidogrel and aspirin compared to 1.1% placebo, as well as 0.7% of patients in CLARITY (n=3491) reported a rash. Drug discontinuation due to skin disorders in CAPRIE was 0.8% and in CURE 0.4% of patients.^[Ref]

Hepatic

• Postmarketing reports: Hepatitis (noninfectious), acute liver failure, abnormal liver function tests^[Ref]

Metabolic

• Common (1% to 10%): Hypercholesterolemia^[Ref]

Genitourinary

• Common (1% to 10%): Urinary tract infection
• Postmarketing reports: Hematuria^[Ref]

Ocular

• Postmarketing reports: Eye bleeds (conjunctival, ocular, retinal)^[Ref]

Other

• Common (1% to 10%): Accidental/inflicted injury, influenza-like symptoms, pain, fatigue, infection
• Postmarketing reports: Fever^[Ref]

Renal

• Uncommon (0.1% to 1%): Hematuria
• Postmarketing reports: Glomerulopathy, serum creatinine increase^[Ref]

Immunologic

• Postmarketing reports: Serum sickness, insulin autoimmune syndrome^[Ref]

Endocrine

• Postmarketing reports: Gynecomastia^[Ref]

Local

• Common (1% to 10%): Puncture site bleeding^[Ref]

Frequently asked questions

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Further information

Clopidogrel side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer