Drug Monograph

Effient (Prasugrel)

prasugrel — also marketed as Efient (EU)
P2Y12 Receptor Antagonist (Thienopyridine) · Oral · Irreversible Antiplatelet Prodrug
Pharmacokinetic Profile
Half-Life (active metabolite)
~7 h (range 2–15 h)
Metabolism
Intestinal hydrolysis → thiolactone → active metabolite (CYP3A4 & CYP2B6 primary)
Protein Binding (active metabolite)
~98%
Absorption
≥79% absorbed; Tmax ~30 min
Volume of Distribution (active metabolite)
44–68 L
Clinical Information
Drug Class
P2Y12 inhibitor (thienopyridine, irreversible)
Available Doses
5 mg, 10 mg tablets
Route
Oral (once daily)
Renal Adjustment
None required; ESRD: limited data, higher bleeding risk
Hepatic Adjustment
None for Child-Pugh A/B; severe disease not studied
Pregnancy
No human data; consider bleeding risk; use only if benefit justifies risk
Lactation
No human data; metabolites in rat milk; weigh risks/benefits
Schedule / Legal Status
Rx only; not scheduled
Black Box Warning
Yes — bleeding risk
Generic Available
Yes (multiple manufacturers since 2017)
Rx

Indications

Prasugrel is a third-generation thienopyridine P2Y12 antagonist with a single FDA indication: reduction of thrombotic cardiovascular events — including stent thrombosis — in patients with acute coronary syndrome who are managed with percutaneous coronary intervention. Unlike ticagrelor, the approved use is narrowly tied to PCI; trials in medically managed acute coronary syndromes (TRILOGY-ACS) and in pretreatment before angiography (ACCOAST) were negative.

IndicationApproved PopulationTherapy TypeStatus
Unstable angina or NSTEMI managed with PCIAdults; coronary anatomy known before loading dose (per FDA PI)Adjunctive to aspirinFDA Approved
STEMI managed with primary or delayed PCIAdults presenting within 12 h (loading at diagnosis) or 12 h–14 d (after angiography)Adjunctive to aspirinFDA Approved
Genotype-guided P2Y12 escalation in clopidogrel CYP2C19 loss-of-function carriersPost-PCI patients with confirmed CYP2C19 LOF allelesSubstitution for clopidogrelOff-label
De-escalation strategy — switch from ticagrelor in chronic phasePost-ACS, stable phase, intolerance to ticagrelor (e.g., dyspnoea)Switch antiplateletOff-label

The pivotal evidence is TRITON-TIMI 38 (Wiviott 2007), in which 13,608 patients with ACS planned for PCI were randomised to prasugrel (60 mg load, 10 mg daily) or clopidogrel (300 mg load, 75 mg daily). The primary composite of cardiovascular death, non-fatal MI, or non-fatal stroke was 9.3% vs 11.2% in the UA/NSTEMI cohort and 9.8% vs 12.2% in the STEMI cohort, both favouring prasugrel; stent thrombosis fell by approximately 50%. The benefit was driven almost entirely by reduction in non-fatal MI, with no difference in cardiovascular mortality. ISAR-REACT 5 (Schüpke 2019) subsequently showed prasugrel superior to ticagrelor on the composite ischaemic endpoint in ACS patients undergoing planned invasive evaluation, with no excess of major bleeding (BARC 3–5 5.4% ticagrelor vs 4.8% prasugrel).

Off-label uses — evidence quality

Genotype-guided escalation (moderate-quality evidence): POPular Genetics and TAILOR-PCI evaluated CYP2C19-guided P2Y12 selection after PCI. Switching from clopidogrel to prasugrel (or ticagrelor) in carriers of loss-of-function alleles is endorsed as a Class IIb recommendation in the 2021 ACC/AHA/SCAI revascularisation guideline.

De-escalation from ticagrelor (low-to-moderate quality): TROPICAL-ACS supported guided de-escalation strategies after the acute phase. Switching from ticagrelor to prasugrel (rather than clopidogrel) is occasionally used when ticagrelor-related dyspnoea limits adherence but ischaemic risk remains high.

Dose

Dosing

Prasugrel dosing is unusually weight-aware for an antiplatelet agent: patients under 60 kg may receive a reduced 5 mg maintenance dose because of substantially higher exposure to the active metabolite and increased bleeding risk in TRITON-TIMI 38. The 60 mg loading dose is used in all weight categories. Once-daily dosing simplifies adherence compared with twice-daily ticagrelor.

Clinical ScenarioStarting DoseMaintenance DoseMaximum DoseNotes
STEMI, primary PCI within 12 h of symptom onset60 mg PO load at diagnosis10 mg PO daily10 mg dailyCo-administer with ASA 75–325 mg
Most patients in TRITON-TIMI 38 received the load at the time of PCI
STEMI presenting 12 h–14 d, delayed PCI60 mg PO load after angiography10 mg PO daily10 mg dailyDefer load until coronary anatomy known
UA / NSTEMI managed with PCI60 mg PO load at PCI10 mg PO daily10 mg dailyPretreatment before angiography is not recommended (ACCOAST: no benefit, increased bleeding)
Body weight <60 kg60 mg PO load (unchanged)5 mg PO daily (consider)5 mg daily5 mg dose not prospectively validated for efficacy
AUC of active metabolite ~30–40% higher in low-weight patients
STEMI / NSTEMI on ticagrelor or clopidogrel — switch to prasugrel60 mg load 24 h after last ticagrelor dose; can switch from clopidogrel without interruption10 mg daily (or 5 mg if <60 kg)10 mg dailyDo not administer prasugrel during cangrelor infusion (cangrelor blocks prasugrel binding)

Special populations

PopulationAdjustmentRationale
Age ≥75 yearsGenerally not recommendedIncreased fatal bleeding (1.0% vs 0.1% clopidogrel) and ICH (0.8% vs 0.3%) in TRITON-TIMI 38; consider only if diabetes or prior MI present and a clear benefit anticipated
Body weight <60 kgConsider 5 mg daily maintenanceHigher active-metabolite exposure; non-CABG bleeding 10.1% vs 6.5% clopidogrel on 10 mg dose
Renal impairment (any stage)No adjustment neededPK of active metabolite similar in moderate impairment; ESRD exposure is approximately half that of healthy controls but bleeding risk is generally higher
Mild to moderate hepatic impairment (Child-Pugh A/B)No adjustmentPK and platelet inhibition similar to healthy subjects
Severe hepatic impairment (Child-Pugh C)Not studied; use with caution given general bleeding riskNo PK/PD data; FDA PI does not list as a contraindication but flags higher bleeding risk
Paediatric (<18 years)Not establishedSickle cell anaemia trial in 2–17-year-olds did not meet primary endpoint of vaso-occlusive crisis reduction
CYP2C19 loss-of-function carriersNo adjustment; may be preferred over clopidogrelPrasugrel’s active metabolite formation is independent of CYP2C19 genotype (FDA PI 8.9, 12.5)
Clinical pearls — dosing and administration

Hold for 7 days before any elective surgery, including CABG — the highest-risk window for bleeding (FDA PI). Withholding a single dose is ineffective because platelet inhibition is irreversible for the platelet’s lifespan.

Do not start prasugrel if urgent CABG is likely. CABG-related TIMI major or minor bleeding was 14.1% vs 4.5% with clopidogrel in TRITON-TIMI 38.

Do not split or crush tablets routinely — the FDA PI explicitly warns against breaking tablets. Crushed administration has been studied for faster onset in primary PCI but is not in the approved labelling.

Aspirin 75–325 mg is the FDA-labelled co-medication; low-dose ASA (81–100 mg) is preferred in current practice.

Cangrelor blocks prasugrel binding when given together. Wait until the cangrelor infusion is complete before administering the prasugrel loading dose.

PK

Pharmacology

Mechanism of Action

Prasugrel is a thienopyridine prodrug that produces irreversible inhibition of platelet activation and aggregation through covalent binding of its active metabolite to the platelet P2Y12 ADP receptor. Two features distinguish it from clopidogrel, the older thienopyridine. First, prasugrel undergoes a more efficient single-step CYP-mediated activation: after rapid intestinal hydrolysis to a thiolactone intermediate, conversion to the active metabolite occurs primarily through CYP3A4 and CYP2B6 (with smaller contributions from CYP2C9 and CYP2C19). Clopidogrel, in contrast, requires two sequential CYP steps with substantial CYP2C19 dependence. Second, prasugrel’s pharmacokinetics and platelet inhibition are not affected by CYP2C19 loss-of-function alleles — a critical advantage in the roughly 30% of patients with reduced clopidogrel responsiveness. Onset is rapid: approximately 90% of patients achieve at least 50% inhibition of platelet aggregation within 1 hour of a 60 mg loading dose, with peak inhibition near 80%. Steady-state inhibition on 10 mg daily averages around 70%, and platelet function recovers over 5–9 days after discontinuation, paralleling new platelet production rather than drug clearance.

ADME profile

ParameterValueClinical Implication
Absorption≥79% absorbed; active metabolite Tmax ~30 min; high-fat meal decreases Cmax 49% and delays Tmax to 1.5 h but does not change AUCFaster onset than clopidogrel; food does not impair overall exposure but may delay effect in primary PCI
DistributionApparent Vd of active metabolite 44–68 L; protein binding ~98% (active metabolite)Limited extravascular distribution; unlikely to cause clinically important protein-displacement interactions
MetabolismPrasugrel itself is undetectable in plasma after dosing; rapid intestinal hydrolysis → thiolactone → active metabolite (CYP3A4 and CYP2B6 primary; CYP2C9 and CYP2C19 minor)CYP2C19 genotype does not meaningfully affect activity; most CYP3A inhibitors and inducers do not alter PK significantly
EliminationActive metabolite t½ ~7 h (range 2–15 h); ~68% urine and ~27% faecal excretion (as inactive metabolites); apparent clearance 112–166 L/hNo renal dose adjustment; active metabolite not effectively dialysable; platelet recovery over 5–9 days driven by new platelet production
Why prasugrel works where clopidogrel sometimes fails

Roughly 30% of Caucasians and a higher proportion of East Asians carry CYP2C19 loss-of-function alleles, reducing clopidogrel’s active metabolite formation. The FDA PI for prasugrel notes there is no relevant effect of genetic variation in CYP2B6, CYP2C9, CYP2C19, or CYP3A5 on prasugrel’s active metabolite or platelet inhibition. Combined with concomitant proton-pump inhibitor use (which inhibits CYP2C19 and was widespread in TRITON-TIMI 38), this pharmacogenomic difference is the leading mechanistic explanation for prasugrel’s greater treatment effect — and its greater bleeding rate — relative to clopidogrel.

SE

Side Effects

All frequency data below are drawn from the FDA prescribing information, which is based on TRITON-TIMI 38 (n=6,741 prasugrel-treated patients; median 14.5 months). Comparators are clopidogrel-treated patients from the same trial unless otherwise noted. Bleeding rates differ markedly by patient subgroup — weight under 60 kg, age over 75, and CABG within 7 days of last dose all substantially increase risk.

≥10% Very Common
Adverse EffectIncidenceClinical Note
CABG-related TIMI major or minor bleeding (in patients undergoing CABG)14.1% vs 4.5% clopidogrelSubstantial bleeding risk in any patient who proceeds to CABG within 7 days of dosing
Within 3 days of last dose: 26.7% vs 5.0% (TRITON-TIMI 38)
Non-CABG bleeding in body weight <60 kg subgroup10.1% vs 6.5% clopidogrelOne of the principal indications for the 5 mg maintenance dose
1–10% Common
Adverse EffectIncidenceClinical Note
Hypertension7.5% vs 7.1% clopidogrelLikely reflects underlying CV comorbidity rather than drug effect
Hypercholesterolaemia / hyperlipidaemia7.0% vs 7.4%Reflects population characteristics
Epistaxis6.2% vs 3.3% clopidogrelMost frequent specifically reported bleeding adverse reaction
Headache5.5% vs 5.3%Generally mild; rarely dose-limiting
Back pain5.0% vs 4.5%Common in post-PCI population
Dyspnoea4.9% vs 4.5%Rate similar to clopidogrel; not the off-target dyspnoea seen with ticagrelor
Nausea4.6% vs 4.3%Take with or without food
Non-CABG TIMI major or minor bleeding (overall)4.5% vs 3.4%Risk highest in the first week after loading
Dizziness4.1% vs 4.6%Consider orthostatic vitals; may be multifactorial
Cough3.9% vs 4.1%Not increased over clopidogrel
Hypotension3.9% vs 3.8%Suspect occult bleeding in any patient who is hypotensive after recent procedure (FDA PI)
Atrial fibrillation2.9% vs 3.1%Reflects baseline cardiovascular risk
Bradycardia2.9% vs 2.4%Common in post-MI population on beta-blockers
Anaemia2.2% vs 2.0%Investigate for occult bleeding; haemoglobin should be tracked
Diarrhoea2.3% vs 2.6%Generally mild; not increased over clopidogrel
GI haemorrhage1.5% vs 1.0%Add PPI in patients with GI bleeding risk factors
Serious Regardless of frequency
Adverse EffectEstimated FrequencyTypical OnsetRequired Action
Non-CABG TIMI major bleeding2.2% vs 1.7% clopidogrelRisk highest in first 7 daysManage without discontinuing if possible (FDA PI); consider platelet transfusion (note: ineffective within 6 h of load or 4 h of maintenance dose)
Life-threatening bleeding (non-CABG)1.3% vs 0.8%Throughout therapyResuscitation; platelet transfusion outside loading window; ICU level care
Symptomatic intracranial haemorrhage0.3% vs 0.3% (overall); 0.8% vs 0.3% in age ≥75Throughout therapyPermanent discontinuation; emergency neuroimaging; neurosurgical input
Fatal bleeding (non-CABG)0.3% vs 0.1% (overall); 1.0% vs 0.1% in age ≥75Any timeResuscitation; root-cause review (mistimed elective surgery, contraindication missed)
CABG-related TIMI major bleeding11.3% vs 3.6%Within 7 days of last doseHold drug 7 days before elective surgery; do not initiate if urgent CABG anticipated
Thrombotic thrombocytopenic purpura (TTP)Rare (postmarketing reports)Often within 2 weeks of startingDiscontinue immediately; haematology consult; urgent plasma exchange (life-threatening)
Hypersensitivity / anaphylaxis / angioedema0.06% angioedema; postmarketing anaphylaxisHours to days; cross-reactivity with other thienopyridines reportedPermanent discontinuation; switch to chemically unrelated agent (ticagrelor)
Severe thrombocytopenia0.06% vs 0.04%VariableDiscontinue; rule out TTP and HIT; haematology referral
Newly diagnosed malignancy (signal in TRITON-TIMI 38)1.6% vs 1.2% (predominantly colon and lung)During therapyCausality unclear; FDA PI notes possible detection bias from bleeding investigations; maintain age-appropriate cancer screening
Discontinuation Withdrawal rates from TRITON-TIMI 38
Adults — All-cause AE discontinuation
7.2% vs 6.3% clopidogrel
Top reasons: bleeding (the dominant cause), allergic/hypersensitivity reactions, and non-haemorrhagic adverse events.
Adults — Bleeding-related discontinuation
2.5% vs 1.4% clopidogrel
Bleeding was the most common adverse event leading to study-drug discontinuation in both arms (FDA PI).
Reason for discontinuationIncidenceContext
Bleeding (any)2.5% vs 1.4%Predominant driver; risk highest in first 7 days; further elevated in age ≥75 and weight <60 kg subgroups
Allergic/hypersensitivity reactions0.36% (similar to clopidogrel)Cross-reactivity with other thienopyridines reported; switch to ticagrelor if needed
Other non-haemorrhagic eventsVariable (rash, GI intolerance, abnormal LFTs)Usually permits switch to another antiplatelet agent without recurrence
Bleeding risk stratification — who should not receive prasugrel

Three populations had disproportionate bleeding risk in TRITON-TIMI 38: patients with prior TIA or stroke (subgroup analysis showed net harm; now a contraindication), patients aged ≥75 (fatal bleeding 1.0% vs 0.1%; ICH 0.8% vs 0.3%; “generally not recommended”), and patients weighing <60 kg (non-CABG bleeding 10.1% vs 6.5%; consider 5 mg dose). The FDA PI advises suspecting bleeding in any post-procedure patient with hypotension — the most clinically important sign of occult haemorrhage in this population.

Int

Drug Interactions

Prasugrel’s clinically meaningful interactions are dominated by additive bleeding from co-administered antithrombotics rather than CYP-mediated pharmacokinetic effects. Per the FDA PI, prasugrel can be administered with most CYP3A inhibitors (including ketoconazole, clarithromycin, diltiazem, verapamil) and inducers (rifampin, carbamazepine) without dose adjustment — ketoconazole reduces Cmax of the active metabolite by 34–46% but does not affect AUC or platelet inhibition. Genetic variation in CYP2C19, CYP2B6, CYP2C9, and CYP3A5 also has no clinically relevant effect.

Major Warfarin and oral anticoagulants (apixaban, rivaroxaban, dabigatran, edoxaban)
MechanismAdditive haemostatic impairment — antiplatelet plus anticoagulant
EffectSignificantly prolonged bleeding time when prasugrel co-administered with 15 mg warfarin (FDA PI); substantial increase in major bleeding
ManagementIn AF + ACS/PCI, current ESC guidance favours clopidogrel + DOAC over prasugrel + DOAC; minimise duration of triple therapy
FDA PI · 2023 ESC ACS
Major Chronic NSAIDs (including COX-2 selective agents)
MechanismNSAID-induced gastric mucosal injury plus additive antiplatelet effect
EffectIncreased GI bleeding risk; chronic NSAIDs were excluded from TRITON-TIMI 38
ManagementAvoid chronic NSAIDs. If unavoidable, co-prescribe PPI; favour paracetamol/topical alternatives
FDA PI
Major Fibrinolytic therapy (alteplase, tenecteplase, reteplase, streptokinase)
MechanismAdditive bleeding risk during the acute lytic window
EffectSubstantially increased major and intracranial bleeding; not studied in patients with recent fibrinolysis <24–48 h
ManagementIn TRITON-TIMI 38, randomisation deferred ≥24 h after tenecteplase/reteplase/alteplase, ≥48 h after streptokinase; clopidogrel preferred immediately post-lysis
FDA PI
Major Cangrelor (intravenous P2Y12 inhibitor)
MechanismCangrelor competitively occupies the P2Y12 receptor and blocks prasugrel’s active metabolite from binding
EffectLoss of expected antiplatelet effect of a 60 mg loading dose if given during cangrelor infusion
ManagementAdminister prasugrel only after the cangrelor infusion has been discontinued
Lexicomp / Medscape
Moderate Opioids (morphine, fentanyl)
MechanismSlowed gastric emptying delays and reduces absorption of prasugrel’s active metabolite
EffectCmax of active metabolite reduced ~31% with concomitant 5 mg IV morphine in healthy adults; delayed onset of platelet inhibition in some patients
ManagementConsider parenteral antiplatelet (cangrelor) in ACS patients receiving opioid analgesia at the time of loading
FDA PI
Moderate SSRIs / SNRIs (sertraline, citalopram, venlafaxine)
MechanismSSRI-induced platelet serotonin depletion adds to P2Y12 inhibition
EffectModest increase in upper GI bleeding (class effect with antiplatelets)
ManagementAdd PPI in patients with GI bleeding risk factors
Lexicomp
Moderate Heparin (unfractionated and low-molecular-weight)
MechanismAdditive haemostatic effects; UFH 100 U/kg + prasugrel prolongs bleeding time
EffectIncreased bleeding time; PK of active metabolite unchanged
ManagementCo-administration is standard during PCI; monitor clinically for bleeding
FDA PI
Minor Strong CYP3A inhibitors (ketoconazole, clarithromycin, ritonavir)
MechanismCYP3A inhibition reduces active-metabolite Cmax
EffectCmax of active metabolite reduced 34–46% with ketoconazole; AUC and platelet inhibition unchanged
ManagementNo dose adjustment; clinically not significant per FDA PI
FDA PI
Minor Strong CYP3A inducers (rifampin, carbamazepine, phenytoin)
MechanismCYP3A induction
EffectRifampicin 600 mg daily did not significantly alter prasugrel active-metabolite PK or platelet inhibition
ManagementNo dose adjustment required (FDA PI)
FDA PI
Minor PPIs (lansoprazole, omeprazole) and H2 blockers (ranitidine)
MechanismReduced gastric absorption of pH-sensitive prodrug
EffectLansoprazole reduced active-metabolite Cmax 29%; ranitidine 14%; AUC and Tmax unchanged
ManagementNo clinically meaningful interaction; PPIs preferred over the clopidogrel context
FDA PI
Why prasugrel is “cleaner” than clopidogrel for drug interactions

Prasugrel’s metabolic pathway uses CYP3A4 and CYP2B6 efficiently in a single activation step, with minor CYP2C19 contribution. Because of this, prasugrel is largely insensitive to PPIs (which inhibit CYP2C19), to CYP2C19 genotype, and to CYP3A modulation in clinical practice. The corollary is that the major interactions are pharmacodynamic (additive bleeding from anticoagulants, NSAIDs, fibrinolytics) rather than pharmacokinetic.

Mon

Monitoring

Routine therapeutic drug monitoring is not used. Bedside platelet function tests (VerifyNow, Multiplate) are not recommended for routine prasugrel management — trials including TROPICAL-ACS, ARCTIC, and ANTARCTIC have not supported tailoring therapy by platelet reactivity outside research protocols. The principal clinical monitoring task is detecting bleeding early.

  • Bleeding signs & symptoms Every visit; daily during inpatient
    Routine
    Ask about bruising, gingival bleeding, epistaxis, melena, haematuria. Inspect mucous membranes. Suspect bleeding in any post-PCI/post-CABG patient who becomes hypotensive (FDA PI). Reinforce when to seek emergency care.
  • Haemoglobin / haematocrit Baseline; daily during admission; trigger-based outpatient
    Trigger-based
    Recheck for unexplained fatigue, dyspnoea, drop in BP, or visible bleeding. Occult GI loss is the commonest cause of asymptomatic anaemia on DAPT.
  • Platelet count Baseline; with new bruising or neurological symptoms
    Trigger-based
    TTP can occur within 2 weeks of starting prasugrel and is life-threatening; check urgently if pentad features (microangiopathic haemolytic anaemia, thrombocytopenia, neurological signs, renal dysfunction, fever) develop. Heparin-induced thrombocytopenia screening if recent heparin exposure.
  • Renal function (eGFR, creatinine) Baseline, then annually
    Routine
    No dose adjustment for any renal stage, but ESRD patients are generally at higher bleeding risk; weigh ongoing benefit-risk in declining renal function.
  • Body weight Baseline, then with significant changes
    Routine
    Crossing the 60 kg threshold (in either direction) should prompt a dose review. The 5 mg dose is an option in patients persistently <60 kg.
  • Liver function (AST, ALT) Baseline, then with symptoms
    Trigger-based
    Abnormal hepatic function in 0.22% in TRITON-TIMI 38 (similar to clopidogrel). Recheck if jaundice, abdominal pain, or unexplained fatigue.
  • Cancer screening Per age-appropriate guideline
    Routine
    TRITON-TIMI 38 reported a small numerical excess of newly diagnosed malignancies (1.6% vs 1.2%, predominantly colon and lung). Causality is unclear; FDA PI suggests detection bias is plausible. Maintain colorectal and lung cancer screening per population recommendations.
  • Adherence assessment Every visit
    Routine
    Once-daily dosing supports adherence relative to ticagrelor. Use pill counts, refill data, or patient-reported missed doses. Premature discontinuation is the largest preventable cause of stent thrombosis on DAPT.
  • Bleeding risk reassessment (PRECISE-DAPT, DAPT score) At 6 and 12 months post-ACS
    Routine
    Drives decisions on duration extension, de-escalation, or shortening of DAPT. Integrate with ischaemic risk (e.g., complex PCI, multi-vessel disease, recurrent events).
Perioperative monitoring

Hold prasugrel for 7 days before any elective surgery, including CABG (FDA PI). For urgent CABG within 7 days of last dose, expect substantial bleeding (TIMI major or minor 14.1% vs 4.5% with clopidogrel). Platelet transfusion may restore haemostasis but is unlikely to be effective within 6 hours of the loading dose or 4 hours of the maintenance dose, because circulating active metabolite will inhibit transfused platelets. There is no specific reversal agent for prasugrel; the active metabolite is not effectively dialysable.

CI

Contraindications & Cautions

FDA Boxed Warning Bleeding risk

Effient can cause significant, sometimes fatal, bleeding. Do not use Effient in patients with active pathological bleeding or a history of transient ischaemic attack or stroke. In patients aged 75 years or older, Effient is generally not recommended, except in high-risk patients (diabetes or prior MI) where its use may be considered. Do not start Effient in patients likely to undergo urgent CABG; when possible, discontinue Effient at least 7 days before any surgery.

Additional risk factors for bleeding include body weight under 60 kg, propensity to bleed, and concomitant medications that increase bleeding risk (e.g., warfarin, heparin, fibrinolytic therapy, chronic NSAID use). Suspect bleeding in any patient who is hypotensive after recent invasive or surgical procedures. If possible, manage bleeding without discontinuing Effient — stopping the drug increases the risk of subsequent cardiovascular events.

Absolute contraindications (FDA prescribing information, Section 4)

  • Active pathological bleeding (e.g., active peptic ulcer haemorrhage, intracranial haemorrhage)
  • History of transient ischaemic attack (TIA) or stroke — ischaemic or haemorrhagic, at any time. In TRITON-TIMI 38, prior TIA/stroke patients had a stroke rate of 6.5% on prasugrel vs 1.2% on clopidogrel
  • Hypersensitivity to prasugrel or any excipient (anaphylaxis, angioedema). Cross-reactivity with other thienopyridines (clopidogrel, ticlopidine) has been reported

Generally not recommended (FDA boxed warning)

  • Age ≥75 years — except in high-risk subgroups: use may be considered in patients with diabetes or prior MI where the benefit-risk balance is more favourable; for all other elderly patients, prefer clopidogrel or ticagrelor
  • Patients likely to undergo urgent CABG: do not initiate
  • Within 7 days of any planned surgery with major bleeding risk

Relative contraindications — specialist input recommended

  • Body weight <60 kg: consider 5 mg maintenance dose; bleeding risk on the 10 mg dose was substantially elevated in TRITON-TIMI 38
  • Severe hepatic impairment (Child-Pugh C): not studied; bleeding risk likely higher
  • End-stage renal disease on dialysis: limited data; generally higher bleeding risk in this population
  • Concomitant oral anticoagulation: 2023 ESC ACS guideline favours clopidogrel over prasugrel in patients requiring concurrent OAC for AF or other indications; minimise duration of triple therapy
  • NSTEMI before coronary anatomy is known (pretreatment): ACCOAST showed no benefit and increased bleeding from pre-angiography loading; defer until PCI is confirmed
  • Recent fibrinolytic therapy: avoid <24 h after tPA-class agents and <48 h after streptokinase (per TRITON-TIMI 38 protocol)
  • Pregnancy: no human data; reserve for situations where benefit clearly outweighs risk
  • Lactation: no human data; metabolites detected in rat milk; discuss benefit-risk with the mother

Use with caution

  • Recent or recurrent GI bleeding, active peptic ulcer disease: treat H. pylori, optimise PPI, reassess net benefit
  • Recent trauma or surgery within prior weeks: weigh bleeding risk against ischaemic protection
  • Concomitant SSRI/SNRI or chronic NSAID use: add PPI; reassess GI bleeding risk factors
  • Planned spinal or epidural anaesthesia: risk of spinal haematoma; coordinate with anaesthesia
  • Severe asthma/COPD: not specifically a prasugrel concern (unlike ticagrelor) but may complicate management of bleeding-related dyspnoea
Pt

Patient Counselling

Purpose of therapy

Explain that prasugrel is a blood-thinning medicine that reduces the risk of another heart attack, blood clot in the stent, or death from cardiovascular causes after acute coronary syndrome treated with stenting. It works by stopping platelets from clumping together at the site of damaged blood vessels. It is taken together with low-dose aspirin — this combination is called dual antiplatelet therapy (DAPT). Stopping prasugrel too early is one of the most common causes of stent thrombosis, a life-threatening blockage of a stent. Patients should never stop the drug without speaking to their cardiologist first.

How to take

Prasugrel is taken once daily, with or without food, ideally at the same time each day. Tablets must not be split, broken, or crushed (FDA PI). If a dose is missed, take it as soon as remembered — but if it is almost time for the next dose, skip the missed dose and take the next dose at the regular time. Doses are never doubled. Continue low-dose aspirin (75–100 mg) every day. The course duration depends on stent type, ischaemic risk, and bleeding risk — typically 12 months after ACS, with possible extension or de-escalation thereafter. Bring a list of all medicines, including over-the-counter products and herbal remedies, to every clinic visit. Keep tablets in the original container with the desiccant.

Bleeding and bruising
Tell patient Easy bruising, prolonged bleeding from small cuts, gum bleeding when brushing, and more frequent nosebleeds are common. Use a soft toothbrush and an electric razor where possible. Inform every dentist, surgeon, and clinician that you take a blood-thinning medicine.
Call prescriber Black or tarry stools, red or pink urine, vomiting blood or coffee-ground material, sudden severe headache, sudden weakness or speech change, coughing up blood, or bleeding that does not stop within 10–15 minutes — seek emergency care immediately.
Stroke or “mini-stroke” (TIA)
Tell patient Prasugrel is not used in patients who have had a stroke or TIA in the past, because it raises the risk of another one. If you experience stroke symptoms while on prasugrel, the medicine will be stopped.
Call prescriber Sudden slurring of speech, sudden weakness or numbness on one side of the body, sudden blurry vision, or sudden severe headache — call emergency services immediately. Do not stop prasugrel on your own; let the emergency team contact your cardiologist.
Surgery and dental procedures
Tell patient Carry a wallet card or use a phone-based medical alert noting that you take a P2Y12 inhibitor and the date of any recent stent. Tell every surgeon and dentist before any procedure, even minor ones.
Call prescriber Before any planned surgery or invasive procedure — ideally at least 14 days in advance. Most major operations require holding prasugrel for 7 days. Routine dental cleaning and simple extractions usually do not require stopping it. Never stop without confirming with your cardiologist.
Body weight and dose
Tell patient If you weigh less than 60 kg (132 pounds), your doctor may prescribe a lower 5 mg dose to reduce the risk of bleeding. Tell your prescriber if your weight changes significantly during treatment.
Call prescriber If you have lost more than 5 kg unintentionally during treatment, or if you are unsure which strength tablet you are taking. Do not change the dose on your own.
Other medicines and supplements
Tell patient Avoid ibuprofen, naproxen, and other anti-inflammatories for routine pain — use paracetamol/acetaminophen instead. Tell your pharmacist about any new prescription, especially blood thinners, antibiotics, or strong painkillers. Drinking alcohol may increase bleeding risk.
Call prescriber If a new doctor prescribes a blood thinner (warfarin, apixaban, rivaroxaban, dabigatran, edoxaban) or a fibrinolytic (“clot-buster”) medication, contact your cardiologist before starting.
Rare blood disorder (TTP)
Tell patient A rare but serious blood-clotting disorder called TTP can occur with prasugrel, sometimes within the first 2 weeks. It needs to be treated in hospital quickly.
Call prescriber Get medical help right away if any of these happen and cannot be explained by another illness: small purplish spots on the skin or mouth, paleness or jaundice, persistent fever, fast heart rate or shortness of breath, confusion or speech changes, or much less urine than usual.
Adherence and missed doses
Tell patient This medicine must be taken every day — missing doses raises the risk of a clot forming inside the stent. Use a pill organiser, alarm, or app reminder. Order refills at least 1 week before running out. Do not break or crush tablets.
Call prescriber If you have missed several doses, or if you injure your head (even after a minor fall), or if any new bleeding develops — let your healthcare team know promptly.
Ref

Sources

Regulatory (PI / SmPC)
  1. U.S. Food and Drug Administration. EFFIENT (prasugrel) tablets — Prescribing Information (revised 12/2020). accessdata.fda.gov/drugsatfda_docs/label/2020/022307s018lbl.pdf Primary regulatory source for indications, dosing, boxed warning, contraindications, adverse-reaction frequencies, and interaction studies.
  2. European Medicines Agency. Efient (prasugrel) Summary of Product Characteristics. ema.europa.eu/en/medicines/human/EPAR/efient European prescribing reference; useful for dosing nuances and additional warnings.
  3. U.S. FDA. Drugs@FDA database, Effient (prasugrel) approval history. accessdata.fda.gov/scripts/cder/daf/ Tracks labelling changes since the original July 2009 approval.
Key Clinical Trials
  1. Wiviott SD, Braunwald E, McCabe CH, et al. Prasugrel versus clopidogrel in patients with acute coronary syndromes (TRITON-TIMI 38). N Engl J Med. 2007;357(20):2001-2015. doi.org/10.1056/NEJMoa0706482 Pivotal randomised trial — basis for the FDA approval and the comparative effectiveness/safety benchmarks against clopidogrel.
  2. Schüpke S, Neumann FJ, Menichelli M, et al. Ticagrelor or prasugrel in patients with acute coronary syndromes (ISAR-REACT 5). N Engl J Med. 2019;381(16):1524-1534. doi.org/10.1056/NEJMoa1908973 Investigator-initiated head-to-head trial showing prasugrel superior to ticagrelor on composite ischaemic endpoint without an excess of major bleeding.
  3. Roe MT, Armstrong PW, Fox KAA, et al. Prasugrel versus clopidogrel for acute coronary syndromes without revascularization (TRILOGY ACS). N Engl J Med. 2012;367(14):1297-1309. doi.org/10.1056/NEJMoa1205512 Negative trial in medically managed NSTE-ACS — defines the boundary of prasugrel’s evidence-supported use.
  4. Montalescot G, Bolognese L, Dudek D, et al. Pretreatment with prasugrel in non–ST-segment elevation acute coronary syndromes (ACCOAST). N Engl J Med. 2013;369(11):999-1010. doi.org/10.1056/NEJMoa1308075 Showed no efficacy benefit and increased bleeding from pretreatment in NSTE-ACS — supports administering the loading dose at PCI.
  5. Savonitto S, Ferri LA, Piatti L, et al. Comparison of reduced-dose prasugrel and standard-dose clopidogrel in elderly patients with acute coronary syndromes undergoing early percutaneous revascularization (Elderly ACS 2). Circulation. 2018;137(23):2435-2445. doi.org/10.1161/CIRCULATIONAHA.117.032180 Tested low-dose (5 mg) prasugrel vs clopidogrel in elderly ACS-PCI patients; trial halted early without efficacy benefit and with bleeding signal.
Guidelines
  1. Byrne RA, Rossello X, Coughlan JJ, et al. 2023 ESC Guidelines for the management of acute coronary syndromes. Eur Heart J. 2023;44(38):3720-3826. doi.org/10.1093/eurheartj/ehad191 Current European recommendations on P2Y12 selection, DAPT duration, and patient-specific choices among prasugrel, ticagrelor, and clopidogrel.
  2. Lawton JS, Tamis-Holland JE, Bangalore S, et al. 2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization. J Am Coll Cardiol. 2022;79(2):e21-e129. doi.org/10.1016/j.jacc.2021.09.006 US revascularisation guidance addressing P2Y12 selection, DAPT after PCI, and genotype-guided strategies.
  3. Levine GN, Bates ER, Bittl JA, et al. 2016 ACC/AHA Guideline focused update on duration of dual antiplatelet therapy in patients with coronary artery disease. J Am Coll Cardiol. 2016;68(10):1082-1115. doi.org/10.1016/j.jacc.2016.03.513 Foundation document for DAPT duration decisions and de-escalation strategies; still cited extensively in practice.
Mechanistic / Basic Science
  1. Brandt JT, Payne CD, Wiviott SD, et al. A comparison of prasugrel and clopidogrel loading doses on platelet function: magnitude of platelet inhibition is related to active metabolite formation. Am Heart J. 2007;153(1):66.e9-66.e16. doi.org/10.1016/j.ahj.2006.10.010 Establishes the more efficient and consistent active-metabolite formation that underlies prasugrel’s pharmacodynamic advantage over clopidogrel.
  2. Mega JL, Close SL, Wiviott SD, et al. Cytochrome P-450 polymorphisms and response to clopidogrel. N Engl J Med. 2009;360(4):354-362. doi.org/10.1056/NEJMoa0809171 Foundational paper on CYP2C19 loss-of-function alleles affecting clopidogrel — the pharmacogenomic basis for preferring prasugrel in known LOF carriers.
Pharmacokinetics / Special Populations
  1. Small DS, Farid NA, Payne CD, et al. Effects of the proton pump inhibitor lansoprazole on the pharmacokinetics and pharmacodynamics of prasugrel and clopidogrel. J Clin Pharmacol. 2008;48(4):475-484. doi.org/10.1177/0091270008315310 Underpins the FDA PI position that PPIs do not meaningfully impair prasugrel activity, in contrast to clopidogrel.
  2. Riesmeyer JS, Salazar DE, Weerakkody GJ, et al. Relationship between exposure to prasugrel active metabolite and clinical outcomes in the TRITON-TIMI 38 substudy. J Clin Pharmacol. 2012;52(6):789-797. doi.org/10.1177/0091270011406280 Defines the exposure-response relationships that justify the 5 mg dose recommendation in patients <60 kg.