Efient: Uses, Dosage & Side Effects
An antiplatelet P2Y12 receptor antagonist for preventing atherothrombotic events in patients with acute coronary syndrome undergoing percutaneous coronary intervention
Efient (prasugrel) is a prescription antiplatelet medication belonging to the thienopyridine class of P2Y12 receptor inhibitors. It is used, in combination with acetylsalicylic acid (aspirin), to prevent atherothrombotic events such as heart attack, stent thrombosis, and cardiovascular death in patients with acute coronary syndrome (ACS) who undergo percutaneous coronary intervention (PCI). Prasugrel acts by irreversibly blocking the P2Y12 adenosine diphosphate (ADP) receptor on platelet surfaces, producing faster, more potent, and more consistent platelet inhibition than clopidogrel. The landmark TRITON-TIMI 38 trial demonstrated that prasugrel significantly reduces ischaemic events compared with clopidogrel, although with an increased risk of major bleeding. Efient is available as 5 mg and 10 mg film-coated tablets.
Quick Facts: Efient
Key Takeaways
- Efient (prasugrel) is a potent antiplatelet P2Y12 receptor inhibitor used with aspirin as dual antiplatelet therapy (DAPT) to prevent blood clots in patients with acute coronary syndrome undergoing percutaneous coronary intervention (stenting).
- The standard adult dose is a single 60 mg loading dose followed by 10 mg once daily; patients aged 75 years or older or weighing less than 60 kg should use the reduced maintenance dose of 5 mg daily.
- In the TRITON-TIMI 38 trial, prasugrel reduced the combined rate of cardiovascular death, non-fatal heart attack, and non-fatal stroke by 19% compared with clopidogrel in ACS patients undergoing PCI.
- The most important risk associated with Efient is bleeding; it is contraindicated in patients with active bleeding, a history of stroke or TIA, or severe hepatic impairment.
- Treatment is typically continued for 12 months after stent placement; premature discontinuation significantly increases the risk of stent thrombosis and should only be done under medical supervision.
What Is Efient and What Is It Used For?
Efient contains the active substance prasugrel, a third-generation thienopyridine antiplatelet agent. It belongs to the class of P2Y12 receptor antagonists, which are medications that prevent blood clots (thrombosis) by inhibiting the activation and aggregation of platelets. Platelets are small blood cells that play a central role in haemostasis (stopping bleeding) but can also contribute to the formation of dangerous blood clots inside arteries, particularly at sites where atherosclerotic plaques have ruptured or where coronary stents have been placed.
Prasugrel is a prodrug, meaning it must be metabolized in the body before becoming pharmacologically active. After oral ingestion, prasugrel is rapidly absorbed from the gastrointestinal tract and undergoes extensive metabolism in the liver. Unlike clopidogrel, which requires a two-step hepatic conversion process and is significantly affected by genetic variations in the CYP2C19 enzyme, prasugrel undergoes a simpler, more efficient metabolic activation pathway. Prasugrel is first hydrolyzed by intestinal esterases to a thiolactone intermediate, which is then converted to the active thiol metabolite primarily by CYP3A4 and CYP2B6 (with minor contributions from CYP2C9 and CYP2C19). This more efficient activation means that prasugrel produces faster onset of action, greater degree of platelet inhibition, and less inter-individual variability in antiplatelet effect compared with clopidogrel.
The active metabolite of prasugrel binds irreversibly to the P2Y12 subtype of adenosine diphosphate (ADP) receptor on the platelet surface. ADP is a key agonist released from activated platelets and damaged vascular tissue that amplifies platelet activation and promotes the formation of stable platelet aggregates. By blocking the P2Y12 receptor, prasugrel prevents ADP from triggering the intracellular signaling cascade that leads to conformational change of the glycoprotein IIb/IIIa (GPIIb/IIIa) receptor on the platelet surface. The GPIIb/IIIa receptor, once activated, binds fibrinogen and von Willebrand factor, cross-linking adjacent platelets to form a platelet plug. Because the binding of prasugrel's active metabolite to the P2Y12 receptor is irreversible, the antiplatelet effect lasts for the remaining lifespan of the affected platelet, which is approximately 7 to 10 days.
Efient is indicated for the prevention of atherothrombotic events in adult patients with acute coronary syndrome (ACS) who undergo percutaneous coronary intervention (PCI). Acute coronary syndrome encompasses a spectrum of conditions caused by sudden reduction of blood flow to the heart muscle, including:
- Unstable angina (UA): Chest pain or discomfort at rest or with minimal exertion, caused by partial obstruction of a coronary artery.
- Non-ST-elevation myocardial infarction (NSTEMI): A heart attack without characteristic ST-segment elevation on the electrocardiogram, indicating partial or intermittent coronary artery occlusion.
- ST-elevation myocardial infarction (STEMI): A heart attack with ST-segment elevation on the electrocardiogram, indicating complete occlusion of a coronary artery requiring urgent revascularisation.
In all three presentations, PCI (also known as coronary angioplasty with stent placement) is frequently performed to restore blood flow through the blocked or narrowed coronary artery. During PCI, a balloon catheter is threaded through the arteries to the site of the blockage, inflated to compress the atherosclerotic plaque, and a metallic stent is deployed to hold the artery open. However, the stent itself represents a foreign body within the blood vessel and is a potent trigger for platelet activation and thrombus formation. Without adequate antiplatelet therapy, the risk of stent thrombosis (a blood clot forming inside the stent) is dangerously high and can lead to heart attack or sudden cardiac death.
The evidence base for Efient is primarily derived from the TRITON-TIMI 38 trial (Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition with Prasugrel–Thrombolysis in Myocardial Infarction 38), a landmark randomised, double-blind, phase III clinical trial published in the New England Journal of Medicine in 2007. This trial enrolled 13,608 patients with moderate-to-high-risk ACS who were scheduled for PCI and compared prasugrel (60 mg loading dose followed by 10 mg daily) with clopidogrel (300 mg loading dose followed by 75 mg daily), both in combination with aspirin.
The primary efficacy endpoint of the TRITON-TIMI 38 trial was the composite of cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke over a median follow-up of 14.5 months. Prasugrel significantly reduced this composite endpoint by 19% compared with clopidogrel (9.9% vs. 12.1%; hazard ratio 0.81; 95% CI 0.73–0.90; p < 0.001). The benefit was driven primarily by a significant reduction in non-fatal myocardial infarction (7.3% vs. 9.5%), including a marked 52% reduction in definite or probable stent thrombosis (1.1% vs. 2.4%). However, prasugrel was also associated with a significant increase in the rate of non-CABG-related TIMI major bleeding (2.4% vs. 1.8%; p = 0.03).
Efient was first approved by the U.S. Food and Drug Administration (FDA) in July 2009 (marketed as Effient in the United States) and by the European Medicines Agency (EMA) in February 2009. It is now approved in numerous countries worldwide. Prasugrel, together with ticagrelor, represents a newer generation of P2Y12 inhibitors that have largely replaced clopidogrel in the management of ACS patients undergoing PCI, as recommended by current guidelines from the European Society of Cardiology (ESC) and the American College of Cardiology/American Heart Association (ACC/AHA).
Efient is always used in combination with low-dose aspirin (typically 75–100 mg daily) as part of dual antiplatelet therapy (DAPT). Aspirin inhibits platelet activation through a different pathway (by blocking cyclooxygenase-1 and thromboxane A2 production), and the combination of aspirin plus a P2Y12 inhibitor provides synergistic antiplatelet protection. Current ESC and ACC/AHA guidelines recommend DAPT for at least 12 months following ACS with PCI, although the optimal duration may be individualised based on the patient's bleeding and ischaemic risk profiles.
What Should You Know Before Taking Efient?
Contraindications
Efient must not be used in the following situations:
- Hypersensitivity: Known allergy to prasugrel or any of the other ingredients in the tablet formulation.
- Active pathological bleeding: Patients with ongoing bleeding, such as a bleeding peptic ulcer, intracranial haemorrhage, or any other condition causing clinically significant active bleeding.
- History of stroke or transient ischaemic attack (TIA): The TRITON-TIMI 38 trial identified that patients with a history of cerebrovascular events had a net clinical harm from prasugrel therapy, with an increased risk of intracranial haemorrhage that outweighed the reduction in ischaemic events.
- Severe hepatic impairment: Patients with severe liver disease (Child-Pugh class C) should not take Efient due to insufficient data on safety and potential for altered drug metabolism and increased bleeding risk.
Warnings and Precautions
Efient inhibits platelet aggregation and therefore increases the risk of bleeding, including potentially life-threatening or fatal bleeding. Seek immediate medical attention if you experience unexplained prolonged or excessive bleeding, blood in your urine or stools, coughing up blood, vomiting blood or material resembling coffee grounds, or signs of internal bleeding such as dizziness, weakness, or unexplained drop in blood pressure.
Before starting Efient, your doctor should be informed about the following conditions and circumstances that may affect the safety of treatment:
- Age 75 years or older: In the TRITON-TIMI 38 trial, patients aged 75 years and older treated with prasugrel did not achieve a net clinical benefit. The rate of fatal bleeding was higher in elderly patients. Efient is generally not recommended in this age group. If, after careful individual assessment, the prescribing physician determines that the benefit outweighs the risk, a reduced maintenance dose of 5 mg daily (instead of 10 mg) should be used after the 60 mg loading dose.
- Body weight less than 60 kg: Patients weighing below 60 kg had higher exposure to the active metabolite of prasugrel and an increased risk of bleeding in clinical trials. A reduced maintenance dose of 5 mg daily is recommended for these patients.
- Propensity to bleed: Conditions that increase the risk of bleeding include recent trauma, recent surgery (especially CABG), active gastrointestinal ulceration, concurrent use of anticoagulants or non-steroidal anti-inflammatory drugs (NSAIDs), and thrombocytopenia. Discuss all bleeding risk factors with your doctor.
- Planned surgery: If elective surgery is planned, Efient should be discontinued at least 7 days before the procedure to allow recovery of platelet function. This includes both surgical and dental procedures. Always inform your surgeon or dentist that you are taking an antiplatelet medication.
- Renal impairment: No dose adjustment is necessary for patients with renal impairment, including those with end-stage renal disease. However, there is limited experience in patients with severe renal disease, and caution is advised.
- Moderate hepatic impairment: No dose adjustment is required for patients with mild to moderate liver disease (Child-Pugh class A or B), but prasugrel should be used with caution in these patients due to limited clinical experience.
Thrombotic thrombocytopenic purpura (TTP) has been reported rarely with prasugrel use. TTP is a serious condition characterised by low platelet count (thrombocytopenia), red blood cell fragmentation (microangiopathic haemolytic anaemia), neurological symptoms, renal dysfunction, and fever. TTP requires urgent medical treatment. Seek immediate medical attention if you develop unexplained bruising, bleeding, purple spots on the skin, yellowing of the skin or eyes, fatigue, or neurological changes while taking Efient.
Pregnancy and Breastfeeding
If you are pregnant, think you may be pregnant, or are planning to become pregnant, consult your doctor before taking Efient. Animal studies have not demonstrated direct harmful effects on embryonic or fetal development, but there are no adequate and well-controlled studies of prasugrel in pregnant women. Due to the antiplatelet mechanism of action, prasugrel may increase the risk of bleeding in the mother and potentially in the fetus or neonate. As a precaution, Efient should not be used during pregnancy unless the potential benefit clearly justifies the potential risk. Women of childbearing potential should use effective contraception during treatment.
It is not known whether prasugrel or its metabolites are excreted in human breast milk. Studies in rats have shown that prasugrel and its metabolites pass into breast milk. A risk to the breastfed infant cannot be excluded. The decision to breastfeed during Efient treatment should be made in consultation with your doctor, carefully weighing the benefits of breastfeeding against the potential risk to the infant.
Driving and Operating Machinery
Efient has no known or negligible effect on the ability to drive or operate machinery. In clinical trials, dizziness was reported uncommonly. If you experience dizziness or any other adverse effects that could impair your ability to drive or use machines, refrain from these activities until the symptoms resolve.
How Does Efient Interact with Other Drugs?
The drug interaction profile of Efient is primarily defined by its pharmacodynamic effects (increased bleeding risk when combined with other medications that affect haemostasis) rather than pharmacokinetic interactions. Prasugrel's active metabolite is formed through hepatic CYP enzymes (primarily CYP3A4 and CYP2B6), but clinically significant metabolic drug interactions are uncommon.
The following table summarises the key drug interactions to be aware of when taking Efient:
| Drug / Drug Class | Type of Interaction | Clinical Significance | Recommendation |
|---|---|---|---|
| Aspirin (acetylsalicylic acid) | Pharmacodynamic (additive antiplatelet) | Required co-administration | Always take together as DAPT (75–100 mg aspirin daily) |
| Warfarin and other oral anticoagulants | Pharmacodynamic (increased bleeding) | Significantly increased bleeding risk | Use with caution; triple therapy only when clearly indicated and for shortest duration |
| NSAIDs (chronic use) | Pharmacodynamic (increased bleeding) | Increased gastrointestinal bleeding risk | Avoid chronic NSAID use; use short courses with gastric protection if needed |
| Heparin (UFH / LMWH) | Pharmacodynamic (increased bleeding) | Used together in acute PCI setting | Permitted during acute PCI; monitor for bleeding |
| GPIIb/IIIa inhibitors | Pharmacodynamic (increased bleeding) | Increased bleeding risk | Can be used in acute PCI as per guidelines; careful bleeding monitoring |
| Fibrinolytic agents | Pharmacodynamic (increased bleeding) | Significantly increased bleeding risk | Not recommended together; if fibrinolysis used, delay prasugrel until PCI |
| Proton pump inhibitors (PPIs) | Pharmacokinetic (minimal) | No clinically significant effect on prasugrel efficacy | Can be used together; no dose adjustment needed |
| Statins (e.g. atorvastatin) | Pharmacokinetic (CYP3A4) | No clinically significant interaction | No dose adjustment needed |
Major Interactions
The most clinically important interactions with Efient involve other medications that impair haemostasis. The combination of Efient with oral anticoagulants (warfarin, dabigatran, rivaroxaban, apixaban, or edoxaban) represents the highest-risk scenario, sometimes referred to as “triple antithrombotic therapy” when aspirin is also continued. This combination may be necessary in patients who have both ACS/PCI and atrial fibrillation requiring anticoagulation, but it carries a substantially elevated risk of major bleeding. Current ESC guidelines recommend that when triple therapy is needed, the duration should be kept as short as possible (typically 1 week to 1 month), followed by a step-down to dual therapy (anticoagulant plus a single antiplatelet agent).
Chronic use of NSAIDs (such as ibuprofen, naproxen, or diclofenac) in combination with Efient and aspirin significantly increases the risk of gastrointestinal bleeding and should be avoided when possible. If an NSAID is required for pain or inflammation, the shortest possible duration should be used, and a proton pump inhibitor should be co-prescribed for gastric protection.
Minor Interactions
An important practical advantage of prasugrel over clopidogrel is that it is not clinically affected by proton pump inhibitors (PPIs). Omeprazole and other PPIs are CYP2C19 inhibitors that have been shown to reduce the antiplatelet effect of clopidogrel, leading to ongoing debate about their concomitant use. Since prasugrel's metabolic activation does not meaningfully depend on CYP2C19, PPIs do not reduce its efficacy. This is particularly relevant because many patients with ACS are co-prescribed PPIs for gastric protection during dual antiplatelet therapy.
Similarly, prasugrel does not have clinically significant pharmacokinetic interactions with statins (atorvastatin, rosuvastatin), angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), beta-blockers, calcium channel blockers, or diuretics, which are commonly prescribed in cardiovascular patients. No dose adjustments of these medications are required when starting Efient.
What Is the Correct Dosage of Efient?
Efient should always be taken exactly as prescribed by your doctor. The dosage regimen consists of a loading dose to rapidly achieve adequate platelet inhibition, followed by a daily maintenance dose to sustain the antiplatelet effect throughout the treatment period. All patients taking Efient must also take low-dose aspirin (75 to 325 mg daily, with 75–100 mg daily preferred for long-term use according to European guidelines).
Adults
| Patient Group | Loading Dose | Maintenance Dose | Duration |
|---|---|---|---|
| Standard adult (under 75 years, ≥60 kg) | 60 mg (single dose) | 10 mg once daily | Up to 12 months |
| Elderly (≥75 years) | 60 mg (single dose) | 5 mg once daily | Up to 12 months; use only if benefit outweighs risk |
| Low body weight (<60 kg) | 60 mg (single dose) | 5 mg once daily | Up to 12 months |
The 60 mg loading dose is typically administered at the time of PCI or as soon as the decision to perform PCI is made. In patients with STEMI, the loading dose may be given as soon as the patient presents and primary PCI is planned. In patients with unstable angina or NSTEMI, the timing of the loading dose depends on the clinical situation and the planned intervention; current guidelines suggest that the loading dose should generally be given once the coronary anatomy is known and PCI is planned, rather than at the time of initial presentation (unlike in STEMI). This approach, known as “pretreatment” avoidance, helps minimise bleeding risk in case the patient ultimately requires coronary artery bypass graft (CABG) surgery instead of PCI.
Efient tablets can be taken with or without food. The tablet should be swallowed whole with water. Do not crush or split the tablets. There is no need to take Efient at a specific time of day, but it is recommended to take it at approximately the same time each day to help maintain consistent platelet inhibition and improve adherence.
Children and Adolescents
Efient is not indicated for use in children and adolescents under 18 years of age. There are no data available on the use of prasugrel in paediatric patients, and ACS with PCI is exceedingly rare in this age group. No dosing recommendations can be made for paediatric patients.
Elderly Patients
In the TRITON-TIMI 38 trial, subgroup analysis of patients aged 75 years and older showed no net clinical benefit from prasugrel 10 mg daily compared with clopidogrel. The risk of fatal and intracranial bleeding was significantly higher in elderly patients. Therefore, Efient is generally not recommended for patients aged 75 years or older. However, if after careful individual assessment (considering both the ischaemic risk, such as diabetes or history of recurrent myocardial infarction, and the bleeding risk), the prescribing physician determines that the benefit outweighs the risk, a reduced maintenance dose of 5 mg once daily should be used following the 60 mg loading dose.
Missed Dose
If you forget to take a dose of Efient, take it as soon as you remember on the same day. If you do not remember until the next day, simply take your normal dose at the usual time. Do not take a double dose to make up for a forgotten dose. Missing doses can reduce the effectiveness of the antiplatelet protection and may increase your risk of stent thrombosis. If you frequently forget doses, consider using a pill organiser or setting a daily alarm on your phone. Contact your doctor or pharmacist if you have concerns about missed doses.
Overdose
If you have taken more Efient than you should, contact your doctor or nearest emergency department immediately. Overdose of prasugrel may result in prolonged bleeding time and subsequent bleeding complications. There is no specific antidote for prasugrel. If rapid reversal of the antiplatelet effect is required (for example, in the event of life-threatening bleeding or emergency surgery), platelet transfusion may be considered, although the effectiveness of platelet transfusion in reversing prasugrel's antiplatelet effect has not been formally established. The active metabolite of prasugrel is not expected to be dialysable due to its extensive protein binding (approximately 98%).
Premature discontinuation of Efient (or any P2Y12 inhibitor) after coronary stent placement significantly increases the risk of stent thrombosis, which can lead to heart attack or death. Do not stop taking Efient without first consulting your cardiologist, even if you feel well. If you experience side effects, speak with your doctor about management options rather than stopping the medication on your own.
What Are the Side Effects of Efient?
Like all medicines, Efient can cause side effects, although not everybody gets them. The most significant side effects are related to its primary pharmacological action of inhibiting platelet aggregation, which inherently increases the risk of bleeding. In the TRITON-TIMI 38 trial, the overall rate of non-CABG-related TIMI major bleeding was 2.4% in the prasugrel group versus 1.8% in the clopidogrel group. Life-threatening bleeding occurred in 1.4% versus 0.9% of patients, and fatal bleeding in 0.4% versus 0.1%, respectively.
The following frequency categories are based on clinical trial data and post-marketing surveillance:
Very Common
May affect more than 1 in 10 people
- Bleeding (any bleeding event, including minor mucocutaneous bleeding, bruising, and prolonged bleeding from cuts)
Common
May affect up to 1 in 10 people
- Haematoma (accumulation of blood under the skin)
- Epistaxis (nosebleeds)
- Gastrointestinal haemorrhage (bleeding from the stomach or intestines)
- Skin rash (erythematous, macular, papular, or urticarial)
- Ecchymosis (bruising, subcutaneous bleeding)
- Haematuria (blood in the urine)
- Puncture site haematoma or bleeding
- Anaemia (decrease in red blood cells or haemoglobin)
Uncommon
May affect up to 1 in 100 people
- Retroperitoneal haemorrhage (bleeding behind the abdominal cavity)
- Haemoptysis (coughing up blood)
- Rectal haemorrhage
- Gingival bleeding (bleeding gums)
- Subcutaneous haematoma
- Post-procedural haemorrhage
- Dizziness
- Headache
- Pruritus (itching)
- Hypersensitivity reactions including angioedema
Rare
May affect up to 1 in 1,000 people
- Thrombotic thrombocytopenic purpura (TTP)
- Intracranial haemorrhage (bleeding in the brain)
- Intraocular haemorrhage (bleeding in the eye)
- Haemopericardium (blood in the sac around the heart)
- Muscle haematoma
- Anaphylaxis (severe allergic reaction)
It is important to understand that some degree of minor bleeding (such as easier bruising or slightly prolonged bleeding from small cuts) is an expected consequence of effective antiplatelet therapy and does not necessarily mean the medication should be stopped. However, any episode of significant or unexplained bleeding should be promptly reported to your healthcare provider.
Skin rash has been reported in approximately 2–3% of patients taking prasugrel in clinical trials. Most rashes were mild to moderate in severity and resolved spontaneously or with standard treatment. However, rash led to discontinuation of prasugrel in some patients. The types of rash reported include erythematous (redness), macular (flat), papular (raised), maculopapular, and urticarial (hive-like) rashes. Rare cases of more severe skin reactions have been reported in post-marketing experience.
If you experience any side effects, including those not listed above, talk to your doctor or pharmacist. You can also report side effects directly to your national adverse drug reaction reporting system (for example, the Yellow Card Scheme in the United Kingdom, MedWatch in the United States, or the corresponding national system in your country). By reporting side effects, you help provide more information on the safety of this medicine.
Contact your doctor or emergency services immediately if you experience: black or bloody stools, vomiting blood or material that looks like coffee grounds, uncontrolled bleeding, sudden severe headache with no known cause, confusion or changes in consciousness, coughing up blood, chest pain or difficulty breathing, or signs of an allergic reaction (swelling of the face, lips, tongue, or throat; difficulty breathing; severe skin rash).
How Should You Store Efient?
Proper storage of Efient is essential to ensure that the medication retains its potency and remains safe to use throughout the treatment period. The following storage guidelines should be observed:
- Temperature: Store below 30°C (86°F). Do not refrigerate or freeze the tablets.
- Moisture protection: Keep the tablets in the original blister packaging until ready to use. The blister packaging is designed to protect the tablets from moisture, which can degrade the active ingredient.
- Light protection: Avoid exposing the tablets to direct sunlight or strong artificial light for prolonged periods.
- Expiry date: Do not use Efient after the expiry date printed on the blister and carton packaging (indicated by “EXP”). The expiry date refers to the last day of the stated month.
- Child safety: Keep Efient out of the sight and reach of children. Store the medication in a secure location, as accidental ingestion by a child could cause serious bleeding complications.
- Disposal: Do not dispose of Efient via household waste or wastewater. Return unused or expired tablets to your pharmacy for safe disposal in accordance with local regulations. This helps protect the environment.
If your tablets appear discoloured, damaged, or show signs of moisture exposure (such as softening or crumbling), do not take them. Contact your pharmacist for a replacement supply.
What Does Efient Contain?
Understanding the full composition of your medication is important, particularly if you have allergies or intolerances to specific ingredients. Each Efient tablet contains the following:
Active Substance
The active ingredient is prasugrel, present as prasugrel hydrochloride. Prasugrel hydrochloride is a white to off-white powder that is practically insoluble in water at pH 2 and freely soluble in methanol and dichloromethane. Each tablet contains either 5 mg or 10 mg of prasugrel (equivalent to 6.29 mg or 12.59 mg of prasugrel hydrochloride, respectively).
Inactive Ingredients (Excipients)
The tablet core contains:
- Microcrystalline cellulose – a bulking and binding agent
- Mannitol (E421) – a sugar alcohol used as a filler and sweetener
- Croscarmellose sodium – a disintegrant that helps the tablet break apart in the stomach
- Hypromellose 2910 – a binder and film-forming agent
- Magnesium stearate – a lubricant used in the manufacturing process
The film coating contains:
- Hypromellose 2910 – film-forming agent
- Titanium dioxide (E171) – a white pigment
- Talc – an anti-adherent agent
- Triacetin – a plasticiser
- Iron oxide yellow (E172) (5 mg tablet) or Iron oxide red (E172) (10 mg tablet) – colouring agents
The 5 mg tablet is yellow and beige-coloured, elongated, and engraved with “5 MG” on one side and “4760” on the other. The 10 mg tablet is beige-coloured, elongated, and engraved with “10 MG” on one side and “4759” on the other. Both tablet strengths are available in blister packs.
Efient contains lactose-free and gluten-free excipients. However, if you have any known intolerances or allergies to any of the listed ingredients, inform your doctor or pharmacist before starting treatment.
Frequently Asked Questions About Efient
Efient (prasugrel) is a prescription antiplatelet medication used to prevent blood clots in patients with acute coronary syndrome (ACS) who are undergoing percutaneous coronary intervention (PCI, also known as coronary stenting). It is always taken together with low-dose aspirin as part of dual antiplatelet therapy (DAPT). Efient helps reduce the risk of heart attack, stent thrombosis, and cardiovascular death.
Efient (prasugrel) and clopidogrel are both P2Y12 receptor inhibitors, but Efient provides faster, more potent, and more consistent platelet inhibition. In the landmark TRITON-TIMI 38 trial, prasugrel significantly reduced the rate of ischaemic events compared to clopidogrel, but with a higher risk of major bleeding. Unlike clopidogrel, prasugrel's activation does not depend heavily on the CYP2C19 enzyme, so it is less affected by genetic variations that can make clopidogrel less effective in some patients.
The most common side effects of Efient are related to its antiplatelet mechanism and include bleeding complications. Common bleeding events include easy bruising, nosebleeds, bleeding from cuts that takes longer to stop, blood in urine or stools, and gastrointestinal bleeding. Other common side effects include skin rash, anaemia, and haematoma. Serious but less common effects include major bleeding events requiring transfusion and thrombotic thrombocytopenic purpura (TTP).
Efient should not be used during pregnancy unless clearly necessary. Animal studies have not shown direct harmful effects on the developing fetus, but there are no adequate and well-controlled studies in pregnant women. The antiplatelet effect of prasugrel may increase the risk of bleeding during pregnancy and delivery. Women of childbearing potential should use effective contraception during treatment. Breastfeeding is not recommended during Efient treatment as it is unknown whether prasugrel or its metabolites pass into human breast milk.
Current guidelines recommend taking Efient as part of dual antiplatelet therapy (DAPT) for at least 12 months after percutaneous coronary intervention (PCI) with stent placement for acute coronary syndrome. In some cases, your cardiologist may recommend a shorter or longer duration based on individual risk factors for bleeding and ischaemic events. Do not stop taking Efient without consulting your doctor, as premature discontinuation can significantly increase the risk of stent thrombosis and heart attack.
Efient must not be used by patients with active pathological bleeding (such as a bleeding stomach ulcer or intracranial haemorrhage), patients who have had a stroke or transient ischaemic attack (TIA), patients with severe liver disease, or those allergic to prasugrel or any of its ingredients. Efient is generally not recommended for patients aged 75 years or older or those weighing less than 60 kg due to an increased risk of bleeding, unless the expected benefit clearly outweighs the risk and a reduced dose of 5 mg daily is used.
References
- European Medicines Agency (EMA). Efient (prasugrel) – Summary of Product Characteristics. Last updated 2024. Available at: ema.europa.eu/en/medicines/human/EPAR/efient
- U.S. Food and Drug Administration (FDA). Effient (prasugrel) Prescribing Information. Revised 2024. Available at: accessdata.fda.gov
- Wiviott SD, Braunwald E, Murphy SA, et al. Prasugrel versus clopidogrel in patients with acute coronary syndromes. N Engl J Med. 2007;357(20):2001–2015. doi:10.1056/NEJMoa0706482
- 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:10.1093/eurheartj/ehad191
- 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:10.1016/j.jacc.2021.09.006
- Angiolillo DJ, Fernandez-Ortiz A, Bernardo E, et al. Variability in individual responsiveness to clopidogrel: clinical implications, management, and future perspectives. J Am Coll Cardiol. 2007;49(14):1505–1516.
- World Health Organization (WHO). Model List of Essential Medicines – 23rd List, 2023. Geneva: WHO; 2023.
- British National Formulary (BNF). Prasugrel. Available at: bnf.nice.org.uk/drugs/prasugrel
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