Plavix (clopidogrel) vs. Effient (prasurgrel)

• Clopidogrel and Effient (prasugrel) are antiplatelet drugs used for preventing strokes, heart attacks, and death in individuals who have had a previous stroke, unstable angina, heart attack, or have peripheral arterial disease (PAD).
• A brand name for clopidogrel is Plavix.
• Side effects of clopidogrel and Effient that are similar include diarrhea, rash, headache, chest pain, dizziness, and increased bleeding.
• Side effects of clopidogrel that are different from Effient include itching, abdominal pain, muscle aches, allergic reactions, pancreatitis, and liver failure.
• Side effects of Effient that are different from clopidogrel include back pain, tired feeling, fatigue, nausea, cough, high or low blood pressure (hypertension or hypotension), shortness of breath, slow heart rate, fever, and swelling or pain in the extremities.

Clopidogrel is an anti-platelet drug used to prevent heart attacks, strokes, and death in patients who have had a previous stroke, unstable angina (chest pain), heart attack, or have peripheral arterial disease (PAD). Clopidogrel prevents blood clots by binding to the P2Y12 receptor on platelets, preventing adenosine diphosphate (ADP) from activating platelets. It belongs to a class of drugs called P2Y12 inhibitors, which also includes prasugrel (Effient) and ticagrelor (Brilinta). Clopidogrel is similar to ticlopidine (Ticlid) in chemical structure and in the way it works.

Effient (prasugrel) is an antiplatelet drug that prevents the platelets in the bloodstream from aggregating and forming blood clots, used to prevent blood clots in people with acute coronary syndrome who are undergoing a procedure after a recent heart attack or stroke, and in people with certain disorders of the heart or blood vessels.

Clopidogrel

The tolerability of clopidogrel is similar to that of aspirin. The more common side effects of clopidogrel are:

• diarrhea,
• rash,
• itching,
• Abdominal pain
• headache,
• chest pain,
• muscle aches,
• dizziness.
• severe bleeding,
• allergic reactions,
• pancreatitis, and
• liver failure.

Ticlopidine (Ticlid) is an antiplatelet medication quite similar to clopidogrel. It has been associated with a severe reduction in white blood cell count in between 0.8% and 1% of persons. The risk of this dangerous side effect with clopidogrel is about 0.04%, much less than with ticlopidine but twice that of aspirin.

Clopidogrel rarely causes a condition called thrombotic thrombocytopenic purpura (TTP) in one out of every 250,000 people. TTP is a serious condition in which blood clots form throughout the body. Blood platelets, which participate in clotting, are consumed, and the result can be bleeding because enough platelets are no longer left to allow blood to clot normally. For comparison, the related drug, ticlodipine (Ticlid), causes TTP 17-50 times more frequently than clopidogrel.

Effient

General Risk of Bleeding

Thienopyridines, including Effient, increase the risk of bleeding. With the dosing regimens used in TRITON-TIMI 38, TIMI (Thrombolysis in Myocardial Infarction) Major (clinically overt bleeding associated with a fall in hemoglobin ≥ 5 g/dL, or intracranial hemorrhage) and TIMI Minor (overt bleeding associated with a fall in hemoglobin of ≥ 3 g/dL but < 5 g/dL) bleeding events were more common on Effient than on clopidogrel.

Do not use Effient in patients with active bleeding, prior TIA or stroke. Other risk factors for bleeding are:

• Age ≥ 75 years. Because of the risk of bleeding (including fatal bleeding) and uncertain effectiveness in patients ≥75 years of age, use of Effient is generally not recommended in these patients, except in high-risk situations (patients with diabetes or history of myocardial infarction) where its effect appears to be greater and its use may be considered.
• CABG or other surgical procedure.
• Body weight < 60 kg. Consider a lower (5 mg) maintenance dose.
• Propensity to bleed (e.g., recent trauma, recent surgery, recent or recurrent gastrointestinal (GI) bleeding, active peptic ulcer disease, or severe hepatic impairment).
• Medications that increase the risk of bleeding (e.g., oral anticoagulants, chronic use of non-steroidal anti-inflammatory drugs [NSAIDs], and fibrinolytic agents). Aspirin and heparin were commonly used in TRITON-TIMI 38.

Thienopyridines inhibit platelet aggregation for the lifetime of the platelet (7-10 days), so withholding a dose will not be useful in managing a bleeding event or the risk of bleeding associated with an invasive procedure.

Because the half-life of prasugrel’s active metabolite is short relative to the lifetime of the platelet, it may be possible to restore hemostasis by administering exogenous platelets; however, platelet transfusions within 6 hours of the loading dose or 4 hours of the maintenance dose may be less effective.

Coronary Artery Bypass Graft Surgery-Related Bleeding

The risk of bleeding is increased in patients receiving Effient who undergo CABG. If possible, Effient should be discontinued at least 7 days prior to CABG. Of the 437 patients who underwent CABG during TRITON-TIMI 38, the rates of CABG-related TIMI Major or Minor bleeding were 14.1% in the Effient group and 4.5% in the clopidogrel group.

The higher risk for bleeding events in patients treated with Effient persisted up to 7 days from the most recent dose of study drug. For patients receiving a thienopyridine within 3 days prior to CABG, the frequencies of TIMI Major or Minor bleeding were 26.7% (12 of 45 patients) in the Effient group, compared with 5.0% (3 of 60 patients) in the clopidogrel group.

For patients who received their last dose of thienopyridine within 4 to 7 days prior to CABG, the frequencies decreased to 11.3% (9 of 80 patients) in the prasugrel group and 3.4% (3 of 89 patients) in the clopidogrel group. Do not start Effient in patients likely to undergo urgent CABG.
CABG-related bleeding may be treated with transfusion of blood products, including packed red blood cells and platelets; however, platelet transfusions within 6 hours of the loading dose or 4 hours of the maintenance dose may be less effective.

Discontinuation of Effient

Discontinue thienopyridines, including Effient, for active bleeding, elective surgery, stroke, or TIA. The optimal duration of thienopyridine therapy is unknown. In patients who are managed with PCI and stent placement, premature discontinuation of any antiplatelet medication, including thienopyridines, conveys an increased risk of stent thrombosis, myocardial infarction, and death. Patients who require premature discontinuation of a thienopyridine will be at increased risk for cardiac events. Lapses in therapy should be avoided, and if thienopyridines must be temporarily discontinued because of an adverse event(s), they should be restarted as soon as possible.

Thrombotic Thrombocytopenic Purpura

Thrombotic thrombocytopenic purpura (TTP) has been reported with the use of Effient. TTP can occur after a brief exposure (< 2 weeks). TTP is a serious condition that can be fatal and requires urgent treatment, including plasmapheresis (plasma exchange). TTP is characterized by thrombocytopenia, microangiopathic hemolytic anemia (schistocytes [fragment red blood cells] seen on peripheral smear), neurological findings, renal dysfunction, and fever.

Hypersensitivity Including Angioedema

Hypersensitivity including angioedema has been reported in patients receiving Effient, including patients with a history of hypersensitivity reaction to other thienopyridines.

Clopidogrel

Clopidogrel bisulfate usually is taken once daily. It can be taken with or without food. Clopidogrel is activated by enzymes in the liver to its active form. Individuals who have reduced activity of liver enzymes that activate clopidogrel due to liver disease may not adequately respond to clopidogrel. Alternative treatments should be used for these patients. The recommended dose for treating unstable angina or heart attack is 300 mg initially followed by 75 mg daily in combination with 75-325 mg of aspirin. Peripheral arterial disease or recent stroke is treated with 75 mg daily.

Effient

Initiate Effient treatment as a single 60 mg oral loading dose and then continue at 10 mg orally once daily. Patients taking Effient should also take aspirin (75 mg to 325 mg) daily.

Effient may be administered with or without food.

Clopidogrel

The combination of clopidogrel with nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Motrin, Advil, Nuprin), naproxen (Naprosyn, Aleve), diclofenac (Voltaren), etodolac (Lodine), nabumetone (Relafen), fenoprofen (Nalfon), flurbiprofen (Ansaid), indomethacin (Indocin), ketoprofen (Orudis; Oruvail), oxaprozin (Daypro), piroxicam (Feldene), sulindac (Clinoril), tolmetin (Tolectin), and mefenamic acid (Ponstel) may increase the risk of stomach and intestinal bleeding.

Combining clopidogrel with warfarin (Coumadin) or other drugs that cause bleeding increases the risk of bleeding.

Clopidogrel is converted to its active form by enzymes in the liver. Drugs that reduce the activity of these enzymes, for example, omeprazole (Prilosec, Zegerid) or esomeprazole (Nexium) may reduce the activity of clopidogrel and should not be used with clopidogrel. Other drugs that also may react with clopidogrel in a similar fashion include fluoxetine (Prozac, Sarafem), cimetidine (Tagamet), fluconazole (Diflucan), ketoconazole (Nizoral, Extina, Xolegel, Kuric), voriconazole (Vfend), ethaverine (Ethatab, Ethavex), felbamate (Felbatol), and fluvoxamine (Luvox).

Effient

• Warfarin
  • Coadministration of Effient and warfarin increases the risk of bleeding
• Non-Steroidal Anti-Inflammatory Drugs
  • Coadministration of Effient and NSAIDs (used chronically) may increase the risk of bleeding.
• Other Concomitant Medications
  • Effient can be administered with drugs that are inducers or inhibitors of cytochrome P450 enzymes.
  • Effient can be administered with aspirin (75 mg to 325 mg per day), heparin, GPIIb/IIIa inhibitors, statins, digoxin, and drugs that elevate gastric pH, including proton pump inhibitors and H2 blockers.

Clopidogrel

There are no adequate studies of clopidogrel in pregnant women.

Studies in rats have shown that clopidogrel appears in breast milk; however, it is not known whether it also appears in human breast milk. Because of a potential for side effects in the nursing infant, the physician must weigh the potential benefits and possible risks before prescribing clopidogrel to nursing mothers.

Effient

There are no adequate and well-controlled studies of Effient use in pregnant women. Reproductive and developmental toxicology studies in rats and rabbits at doses of up to 30 times the recommended therapeutic exposures in humans (based on plasma exposures to the major circulating human metabolite) revealed no evidence of fetal harm; however, animal studies are not always predictive of a human response. Effient should be used during pregnancy only if the potential benefit to the mother justifies the potential risk to the fetus.

In embryo fetal developmental toxicology studies, pregnant rats and rabbits received prasugrel at maternally toxic oral doses equivalent to more than 40 times the human exposure. A slight decrease in pup body weight was observed; but, there were no structural malformations in either species. In prenatal and postnatal rat studies, maternal treatment with prasugrel had no effect on the behavioral or reproductive development of the offspring at doses greater than 150 times the human exposure.

It is not known whether Effient is excreted in human milk; however, metabolites of Effient were found in rat milk. Because many drugs are excreted in human milk, prasugrel should be used during nursing only if the potential benefit to the mother justifies the potential risk to the nursing infant.