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Last reviewed on RxList: 8/17/2017
Effient Side Effects Center

Last reviewed on RxList 08/17/2017

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. Side effects of Effient include:

  • an increased tendency for bleeding,
  • headache,
  • dizziness,
  • back pain,
  • minor chest pain,
  • tired feeling,
  • fatigue,
  • nausea,
  • cough,
  • high or low blood pressure (hypertension or hypotension),
  • shortness of breath,
  • slow heart rate,
  • rash,
  • fever,
  • swelling or pain in the extremities, and
  • diarrhea.

Effient treatment is started as a single 60-mg oral loading dose and then continued at 10 mg orally once daily. Patients taking Effient should also take aspirin (75 mg to 325 mg) daily. Effient may interact with NSAIDs (nonsteroidal anti-inflammatory drugs) or warfarin. Tell your doctor all medications and supplements you use. There are no adequate and well-controlled studies of Effient use in pregnant women, although studies in animals did not show any evidence of harm to the developing fetus. Effient should be used during pregnancy only if the potential benefit to the mother justifies the potential risk to the fetus. It is unknown whether prasugrel is excreted in human milk.

Our Effient Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Effient Consumer Information

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

  • unusual bleeding such as nosebleeds, bleeding gums, or any bleeding that will not stop;
  • pale skin, fever, easy bruising, purple or red spots under your skin;
  • jaundice (yellowing of the skin or eyes);
  • unexpected vaginal bleeding;
  • feeling very weak or dizzy;
  • blood in your urine or stools, black or tarry stools;
  • coughing up blood or vomit that looks like coffee grounds;
  • chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, general ill feeling;
  • sudden numbness or weakness, especially on one side of the body; or
  • sudden headache, confusion, problems with vision, speech, or balance.

Less serious side effects may include:

  • mild headache or dizziness;
  • back pain, minor chest pain;
  • cough;
  • nausea; or
  • tired feeling.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Effient (Prasugrel Tablets)

Effient Professional Information


The following serious adverse reactions are also discussed elsewhere in the labeling:

Clinical Trials Experience

Safety in patients with ACS undergoing PCI was evaluated in a clopidogrel-controlled study, TRITON-TIMI 38, in which 6741 patients were treated with Effient (60-mg loading dose and 10-mg once daily) for a median of 14.5 months (5802 patients were treated for over 6 months; 4136 patients were treated for more than 1 year). The population treated with Effient was 27 to 96 years of age, 25% female, and 92% Caucasian. All patients in the TRITON-TIMI 38 study were to receive aspirin. The dose of clopidogrel in this study was a 300-mg loading dose and 75-mg once daily.

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials cannot be directly compared with the rates observed in other clinical trials of another drug and may not reflect the rates observed in practice.

Drug Discontinuation

The rate of study drug discontinuation because of adverse reactions was 7.2% for Effient and 6.3% for clopidogrel. Bleeding was the most common adverse reaction leading to study drug discontinuation for both drugs (2.5% for Effient and 1.4% for clopidogrel). Bleeding


Unrelated to CABG Surgery - In TRITON-TIMI 38, overall rates of TIMI Major or Minor bleeding adverse reactions unrelated to coronary artery bypass graft surgery (CABG) were significantly higher on Effient than on clopidogrel, as shown in Table 1.

Table 1: Non-CABG-Related Bleedinga (TRITON-TIMI 38)

  Effient (%)
Clopidogrel (%)
TIMI Major or Minor bleeding 4.5 3.4
TIMI Major bleedingb 2.2 1.7
  Life-threatening 1.3 0.8
    Fatal 0.3 0.1
    Symptomatic intracranial hemorrhage (ICH) 0.3 0.3
    Requiring inotropes 0.3 0.1
    Requiring surgical intervention 0.3 0.3
    Requiring transfusion ( ≥ 4 units) 0.7 0.5
TIMI Minor bleedingb 2.4 1.9
a Patients may be counted in more than one row.
b See WARNINGS AND PRECAUTIONS for definition.

Figure 1 demonstrates non-CABG related TIMI Major or Minor bleeding. The bleeding rate is highest initially, as shown in Figure 1 (inset: Days 0 to 7) [see WARNINGS AND PRECAUTIONS].

Bleeding by Weight and Age - In TRITON-TIMI 38, non-CABG-related TIMI Major or Minor bleeding rates in patients with the risk factors of age ≥ 75 years and weight < 60 kg are shown in Table 2.

Table 2: Bleeding Rates for Non-CABG-Related Bleeding by Weight and Age (TRITON-TIMI 38)

  Major/Minor Fatal
Effienta (%) Clopidogrelb (%) Effienta (%) Clopidogrelb (%)
Weight < 60 kg (N=308 Effient, N=356 clopidogrel) 10.1 6.5 0.0 0.3
Weight ≥ 60 kg (N=6373 Effient, N=6299 clopidogrel) 4.2 3.3 0.3 0.1
Age < 75 years (N=5850 Effient, N=5822 clopidogrel) 3.8 2.9 0.2 0.1
Age ≥ 75 years (N=891 Effient, N=894 clopidogrel) 9.0 6.9 1.0 0.1
a 10-mg Effient maintenance dose
b 75-mg clopidogrel maintenance dose

Bleeding Related to CABG - In TRITON-TIMI 38, 437 patients who received a thienopyridine underwent CABG during the course of the study. The rate of CABG-related TIMI Major or Minor bleeding was 14.1% for the Effient group and 4.5% in the clopidogrel group (see Table 3). The higher risk for bleeding adverse reactions in patients treated with Effient persisted up to 7 days from the most recent dose of study drug.

Table 3: CABG-Related Bleedinga (TRITON-TIMI 38)

  Effient (%)
Clopidogrel (%)
TIMI Major or Minor bleeding 14.1 4.5
TIMI Major bleeding 11.3 3.6
  Fatal 0.9 0
  Reoperation 3.8 0.5
  Transfusion of ≥ 5 units 6.6 2.2
  Intracranial hemorrhage 0 0
TIMI Minor bleeding 2.8 0.9
a Patients may be counted in more than one row.

Bleeding Reported as Adverse Reactions - Hemorrhagic events reported as adverse reactions in TRITON-TIMI 38 were, for Effient and clopidogrel, respectively: epistaxis (6.2%, 3.3%), gastrointestinal hemorrhage (1.5%, 1.0%), hemoptysis (0.6%, 0.5%), subcutaneous hematoma (0.5%, 0.2%), post-procedural hemorrhage (0.5%, 0.2%), retroperitoneal hemorrhage (0.3%, 0.2%), pericardial effusion/hemorrhage/tamponade (0.3%, 0.2%), and retinal hemorrhage (0.0%, 0.1%).


During TRITON-TIMI 38, newly-diagnosed malignancies were reported in 1.6% and 1.2% of patients treated with prasugrel and clopidogrel, respectively. The sites contributing to the differences were primarily colon and lung. In another Phase 3 clinical study of ACS patients not undergoing PCI, in which data for malignancies were prospectively collected, newly-diagnosed malignancies were reported in 1.8% and 1.7% of patients treated with prasugrel and clopidogrel, respectively. The site of malignancies was balanced between treatment groups except for colorectal malignancies. The rates of colorectal malignancies were 0.3% prasugrel, 0.1% clopidogrel and most were detected during investigation of GI bleed or anemia. It is unclear if these observations are causally-related, are the result of increased detection because of bleeding, or are random occurrences.

Other Adverse Events

In TRITON-TIMI 38, common and other important non-hemorrhagic adverse events were, for Effient and clopidogrel, respectively: severe thrombocytopenia (0.06%, 0.04%), anemia (2.2%, 2.0%), abnormal hepatic function (0.22%, 0.27%), allergic reactions (0.36%, 0.36%), and angioedema (0.06%, 0.04%). Table 4 summarizes the adverse events reported by at least 2.5% of patients.

Table 4: Non-Hemorrhagic Treatment Emergent Adverse Events Reported by at Least 2.5% of Patients in Either Group

  Effient (%)
Clopidogrel (%)
Hypertension 7.5 7.1
Hypercholesterolemia/Hyperlipidemia 7.0 7.4
Headache 5.5 5.3
Back pain 5.0 4.5
Dyspnea 4.9 4.5
Nausea 4.6 4.3
Dizziness 4.1 4.6
Cough 3.9 4.1
Hypotension 3.9 3.8
Fatigue 3.7 4.8
Non-cardiac chest pain 3.1 3.5
Atrial fibrillation 2.9 3.1
Bradycardia 2.9 2.4
Leukopenia ( < 4 x 109 WBC/L) 2.8 3.5
Rash 2.8 2.4
Pyrexia 2.7 2.2
Peripheral edema 2.7 3.0
Pain in extremity 2.6 2.6
Diarrhea 2.3 2.6

Postmarketing Experience

The following adverse reactions have been identified during post approval use of Effient. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Blood and lymphatic system disorders - Thrombocytopenia, Thrombotic thrombocytopenic purpura (TTP) [see WARNINGS AND PRECAUTIONS and PATIENT INFORMATION]

Immune system disorders - Hypersensitivity reactions including anaphylaxis [see CONTRAINDICATIONS]

Read the entire FDA prescribing information for Effient (Prasugrel Tablets)

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© Effient Patient Information is supplied by Cerner Multum, Inc. and Effient Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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