Clopidogrel Orion
Antiplatelet agent for prevention of atherothrombotic events
Quick Facts about Clopidogrel Orion
Key Takeaways about Clopidogrel Orion
- Prevents blood clots: Clopidogrel Orion irreversibly inhibits platelet aggregation, reducing the risk of heart attack, stroke, and vascular death in patients with atherosclerotic disease
- Do not stop without medical advice: Stopping clopidogrel prematurely, especially after coronary stent placement, can lead to life-threatening stent thrombosis
- Avoid certain proton pump inhibitors: Omeprazole and esomeprazole can reduce clopidogrel's effectiveness; pantoprazole is a safer alternative if stomach protection is needed
- Increased bleeding risk: Report any unusual bruising, prolonged bleeding, blood in stools or urine, or unexplained nosebleeds to your doctor immediately
- Genetic variation matters: Some patients are CYP2C19 poor metabolisers and may not respond adequately to clopidogrel; your doctor may consider alternative medications
What Is Clopidogrel Orion and What Is It Used For?
Clopidogrel Orion is an antiplatelet medicine that prevents blood platelets from sticking together, thereby reducing the formation of blood clots. It is used in adults to prevent atherothrombotic events following myocardial infarction, ischaemic stroke, or in patients with established peripheral arterial disease.
Clopidogrel belongs to the thienopyridine class of antiplatelet agents and is classified as a P2Y12 receptor antagonist. When you suffer an injury to a blood vessel, platelets normally clump together to form a clot and stop bleeding. However, in people with atherosclerosis (hardening of the arteries), this clotting process can occur inside blood vessels, blocking the flow of blood to vital organs like the heart or brain. Clopidogrel works by selectively and irreversibly blocking a specific receptor called P2Y12 on the surface of platelets, preventing them from being activated by adenosine diphosphate (ADP), one of the key chemical signals that triggers platelet clumping.
Clopidogrel Orion is a generic formulation manufactured by Orion Corporation, containing the same active substance as the original branded product. It is bioequivalent to the originator product, meaning it delivers the same amount of active drug into the bloodstream at the same rate. The European Medicines Agency (EMA) and national regulatory authorities have approved numerous generic clopidogrel formulations following patent expiry of the original product.
Clopidogrel Orion is approved for several important clinical indications. In patients who have recently suffered a myocardial infarction (heart attack), it reduces the risk of subsequent cardiovascular events. For patients with recent ischaemic stroke, it helps prevent recurrent strokes and other vascular events. In people diagnosed with peripheral arterial disease (PAD), it reduces the risk of ischaemic events. Additionally, when used in combination with aspirin (dual antiplatelet therapy, or DAPT), clopidogrel is a cornerstone treatment for patients with acute coronary syndrome (unstable angina or non-ST-elevation myocardial infarction) and after percutaneous coronary intervention (PCI) with stent placement.
The landmark CAPRIE trial, published in The Lancet, demonstrated that clopidogrel was slightly more effective than aspirin alone in reducing the combined risk of ischaemic stroke, myocardial infarction, or vascular death. The CURE trial further established the benefit of dual antiplatelet therapy with clopidogrel plus aspirin in patients with acute coronary syndrome, showing a 20% relative risk reduction in major cardiovascular events compared to aspirin alone.
Clopidogrel Orion is a prescription-only medicine. It should only be taken under the supervision of a qualified healthcare professional who can assess your cardiovascular risk profile and determine the appropriate duration of treatment. Never start or stop this medicine without consulting your doctor.
What Should You Know Before Taking Clopidogrel Orion?
Before taking Clopidogrel Orion, inform your doctor about all medical conditions, medications, and planned surgeries. Clopidogrel is contraindicated in patients with active pathological bleeding, severe liver impairment, or known hypersensitivity to clopidogrel. Special caution is required during pregnancy and breastfeeding.
Contraindications
Clopidogrel Orion must not be used if you have any of the following conditions:
- Hypersensitivity to clopidogrel or any of the excipients in the tablet
- Active pathological bleeding, such as a peptic ulcer or intracranial haemorrhage
- Severe hepatic impairment, as the liver is required to convert clopidogrel into its active form
If you have previously experienced an allergic reaction to clopidogrel or other thienopyridine antiplatelet agents (such as ticlopidine or prasugrel), tell your doctor immediately, as cross-reactivity may occur. Symptoms of an allergic reaction may include skin rash, itching, swelling of the face or throat, and difficulty breathing.
Warnings and Precautions
Your doctor should be informed about the following conditions before you start taking Clopidogrel Orion:
- Risk of bleeding: Clopidogrel increases the risk of bleeding. Report any unusual or prolonged bleeding to your doctor. If you are scheduled for surgery, including dental procedures, inform the surgeon that you are taking clopidogrel at least 5-7 days before the procedure
- Recent stroke: In the first 7 days after an acute ischaemic stroke, combined use of clopidogrel and aspirin has been associated with increased risk of major haemorrhage
- Thrombotic thrombocytopenic purpura (TTP): This rare but serious condition has been reported very rarely, sometimes after only a short period of use. It is characterised by low platelet count, destruction of red blood cells, kidney problems, fever, and neurological symptoms. Seek immediate medical attention if you develop any of these symptoms
- Acquired haemophilia: Acquired haemophilia has been reported rarely. If isolated prolonged activated partial thromboplastin time (aPTT) is confirmed, with or without bleeding, acquired haemophilia should be considered
- CYP2C19 poor metaboliser status: Clopidogrel is a prodrug that requires conversion to its active form by the liver enzyme CYP2C19. Patients who are poor metabolisers of CYP2C19 (approximately 2-14% of the population depending on ethnicity) may have reduced platelet inhibition and an increased risk of cardiovascular events. Genetic testing may be considered in certain clinical situations
- Renal impairment: Limited experience exists in patients with severe renal impairment. Use clopidogrel with caution in this group
If you have had a coronary stent placed, stopping clopidogrel prematurely is extremely dangerous. Stent thrombosis (a blood clot forming inside the stent) is a medical emergency that can lead to heart attack and death. Always follow your cardiologist's instructions regarding the duration of treatment, which is typically 6-12 months after stent placement.
Pregnancy and Breastfeeding
There is limited clinical data on the use of clopidogrel during pregnancy. Animal studies have not shown direct harmful effects on pregnancy, embryonal or foetal development, parturition, or postnatal development. However, as a precautionary measure, clopidogrel should preferably not be used during pregnancy unless the clinical condition of the patient requires treatment and no safer alternative is available.
It is not known whether clopidogrel is excreted in human breast milk. Studies in rats have shown that clopidogrel and its metabolites are excreted in milk. Breastfeeding should be discontinued during treatment with clopidogrel. Discuss alternative feeding methods with your healthcare provider if you need to take clopidogrel.
If you are pregnant, planning to become pregnant, or breastfeeding, consult your doctor before taking Clopidogrel Orion. Your physician will carefully weigh the potential benefits against the risks and may consider alternative antiplatelet agents with better safety data during pregnancy and lactation.
How Does Clopidogrel Orion Interact with Other Drugs?
Clopidogrel Orion interacts with several medications, most importantly certain proton pump inhibitors (omeprazole, esomeprazole) that can reduce its effectiveness, and blood thinners (warfarin, heparins) that increase bleeding risk. Always tell your doctor about all medicines you are taking.
Drug interactions with clopidogrel are clinically significant because they can either reduce its antiplatelet effectiveness (increasing the risk of cardiovascular events) or increase the risk of bleeding. Clopidogrel is a prodrug that requires activation by the hepatic cytochrome P450 enzyme system, particularly the CYP2C19 isoenzyme. Medications that inhibit CYP2C19 can reduce the formation of the active metabolite and diminish the antiplatelet effect of clopidogrel.
Major Interactions
| Drug / Class | Type of Interaction | Clinical Effect | Recommendation |
|---|---|---|---|
| Omeprazole, Esomeprazole | CYP2C19 inhibition | Reduced clopidogrel activation, decreased antiplatelet effect | Avoid. Use pantoprazole or lansoprazole instead |
| Warfarin | Additive bleeding risk | Increased risk of haemorrhage | Avoid concomitant use unless clearly indicated; monitor INR closely |
| NSAIDs (ibuprofen, naproxen) | Additive bleeding risk + GI irritation | Increased risk of gastrointestinal bleeding | Use with caution; consider gastroprotection with pantoprazole |
| SSRIs (fluoxetine, paroxetine) | CYP2C19 inhibition + serotonin effect on platelets | Reduced clopidogrel activation, increased bleeding risk | Consider alternative antidepressant; monitor for bleeding |
| Heparins (LMWH, UFH) | Additive anticoagulant effect | Significantly increased bleeding risk | Use only under medical supervision; monitor closely |
Minor Interactions
The following interactions are generally less clinically significant but should still be discussed with your doctor:
- Aspirin (acetylsalicylic acid): When used in combination (dual antiplatelet therapy), aspirin and clopidogrel have an additive effect on platelet inhibition. This combination is intentionally prescribed after acute coronary syndrome and stent placement. However, the increased bleeding risk means that the combination should only be used for the prescribed duration
- Pantoprazole, lansoprazole, rabeprazole: These proton pump inhibitors have minimal effect on CYP2C19 and are considered safer alternatives to omeprazole when gastric protection is needed alongside clopidogrel therapy
- Morphine and other opioids: Opioid analgesics can delay the absorption of orally administered drugs, including clopidogrel, potentially leading to delayed onset of antiplatelet effect. This interaction is most relevant in the acute setting (e.g., during myocardial infarction)
- Repaglinide: Clopidogrel may increase plasma concentrations of repaglinide by inhibiting CYP2C8. Blood glucose monitoring is recommended if these drugs are used together
Tell your doctor or pharmacist about all medicines you are currently taking, including prescription drugs, over-the-counter medications, herbal remedies (especially St John's Wort, which may affect CYP enzymes), and dietary supplements. Some medications interact with clopidogrel in ways that can be dangerous.
What Is the Correct Dosage of Clopidogrel Orion?
The standard dose of Clopidogrel Orion for adults is 75 mg once daily, taken by mouth with or without food. In some conditions, a loading dose of 300 mg may be given initially. The duration of treatment depends on the indication and your doctor's assessment.
Adults
The recommended dose of Clopidogrel Orion depends on the clinical indication. In all cases, the tablet should be swallowed whole with water and can be taken with or without food. It is advisable to take clopidogrel at the same time each day to maintain consistent blood levels.
| Indication | Loading Dose | Maintenance Dose | Duration |
|---|---|---|---|
| Recent MI, ischaemic stroke, or PAD | None required | 75 mg once daily | Long-term (as directed by physician) |
| Acute coronary syndrome (NSTEMI/UA) | 300 mg single dose | 75 mg once daily (+ aspirin 75-100 mg) | Up to 12 months |
| STEMI (with fibrinolysis) | 300 mg (age <75) or none (age ≥75) | 75 mg once daily (+ aspirin) | At least 4 weeks, up to 12 months |
| After PCI with stent | 300-600 mg | 75 mg once daily (+ aspirin 75-100 mg) | 6-12 months (or longer per guidelines) |
| Atrial fibrillation (if OAC unsuitable) | None | 75 mg once daily (+ aspirin 75-100 mg) | As directed by physician |
Children and Adolescents
Clopidogrel Orion is not recommended for children and adolescents under 18 years of age. The safety and efficacy of clopidogrel have not been established in the paediatric population for the approved indications. Clinical trials in paediatric patients with sickle cell disease did not demonstrate a favourable benefit-risk profile. If antiplatelet therapy is required in children, the treating physician should consider alternative agents with established paediatric safety data.
Elderly Patients
No dose adjustment is necessary for elderly patients. Clopidogrel has been extensively studied in patients over 65 years of age, and the 75 mg daily dose provides adequate antiplatelet effect regardless of age. However, elderly patients are generally at increased risk of bleeding due to age-related factors such as more fragile blood vessels, concurrent use of multiple medications, and declining renal function. Therefore, careful monitoring for signs of bleeding is particularly important in this population. The CURE and CAPRIE trials included substantial proportions of elderly patients and confirmed the benefit of clopidogrel in this age group.
Missed Dose
If you miss a dose of Clopidogrel Orion:
- If you remember within 12 hours of your usual time, take the missed dose immediately and then continue with your regular schedule
- If more than 12 hours have passed, skip the missed dose and take the next dose at the usual time
- Do not take a double dose to make up for a missed one, as this increases the risk of bleeding
- If you miss doses frequently, consider setting a daily alarm or using a pill organiser to help you remember
Overdose
Overdose with clopidogrel may lead to prolonged bleeding time and subsequent bleeding complications. There is no specific antidote for clopidogrel. If rapid correction of the antiplatelet effect is required (for example, due to life-threatening bleeding or emergency surgery), platelet transfusion may be considered. If you suspect an overdose, contact your local poison control centre or emergency services immediately. Symptoms to watch for include severe or uncontrollable bleeding, bloody or black tarry stools, vomiting blood, or unusual bruising.
What Are the Side Effects of Clopidogrel Orion?
The most common side effects of Clopidogrel Orion are related to bleeding, including bruising, nosebleeds, and gastrointestinal bleeding. Other common side effects include diarrhoea, abdominal pain, and dyspepsia. Serious but rare side effects include thrombotic thrombocytopenic purpura (TTP) and severe haemorrhage.
Like all medicines, Clopidogrel Orion can cause side effects, although not everybody gets them. The side effects listed below are organised by how frequently they occur, based on data from clinical trials involving thousands of patients and post-marketing surveillance reports. The most important side effects to be aware of are bleeding events, which are a direct consequence of the drug's antiplatelet mechanism of action.
Common
- Haematoma (bruising)
- Nosebleeds (epistaxis)
- Gastrointestinal bleeding
- Diarrhoea
- Abdominal pain
- Dyspepsia (indigestion)
- Bleeding at puncture or injection sites
Uncommon
- Thrombocytopenia (low platelet count)
- Leucopenia (low white blood cell count)
- Eosinophilia (increased eosinophil count)
- Headache, dizziness, paraesthesia (tingling)
- Gastric ulcer, duodenal ulcer
- Gastritis (stomach inflammation)
- Nausea, vomiting, flatulence, constipation
- Rash, pruritus (itching), skin bleeding (purpura)
- Haematuria (blood in urine)
- Prolonged bleeding time
Rare
- Neutropenia (very low white blood cells), including severe neutropenia
- Vertigo
- Retroperitoneal haemorrhage
- Intracranial bleeding (bleeding in the brain)
- Ocular bleeding (eye haemorrhage)
Very Rare
- Thrombotic thrombocytopenic purpura (TTP)
- Aplastic anaemia, pancytopenia, agranulocytosis
- Severe liver disorders (hepatitis, acute liver failure)
- Severe skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis, erythema multiforme)
- Angioedema (severe allergic swelling)
- Serum sickness-like reaction
- Vasculitis (inflammation of blood vessels)
- Stomatitis (mouth ulcers)
- Bronchospasm, interstitial pneumonitis
- Glomerulonephritis (kidney inflammation)
- Arthralgia (joint pain), arthritis, myalgia (muscle pain)
Unexplained fever with bruising or small red spots under the skin, confusion, jaundice (yellowing of skin/eyes), severe skin blistering, blood in urine or stools, vomiting blood, severe or uncontrollable bleeding from any site, or sudden onset of weakness in the face, arms or legs (which may indicate a stroke). These may be signs of serious conditions such as TTP, liver failure, or severe haemorrhage that require emergency treatment.
The frequency of bleeding events increases when clopidogrel is used in combination with aspirin (dual antiplatelet therapy). In the CURE trial, the rate of major bleeding was 3.7% in the clopidogrel plus aspirin group compared to 2.7% in the aspirin alone group. However, the reduction in cardiovascular events typically outweighs this increased bleeding risk in appropriately selected patients. Your doctor will assess your individual bleeding risk against the expected cardiovascular benefit before prescribing this combination.
If you experience any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed above. You can also report side effects directly to your national reporting system (e.g., the Yellow Card Scheme in the UK, MedWatch in the USA, or the EudraVigilance system in the EU), which helps monitor the safety of medicines after they have been approved for use.
How Should You Store Clopidogrel Orion?
Store Clopidogrel Orion below 25°C in the original packaging to protect from moisture. Keep out of the sight and reach of children. Do not use after the expiry date stated on the packaging.
Proper storage of medication is essential to ensure its continued effectiveness and safety. Clopidogrel Orion film-coated tablets should be stored according to the following guidelines:
- Temperature: Store below 25°C (77°F). Do not freeze. Avoid exposure to excessive heat or direct sunlight
- Moisture protection: Keep the tablets in the original blister packaging until ready to use to protect from moisture. Do not store in humid environments such as bathrooms
- Child safety: Keep out of the sight and reach of children. Consider using a locked medicine cabinet
- Expiry date: Do not use the tablets after the expiry date (EXP) printed on the blister and carton. The expiry date refers to the last day of that month
- Disposal: Do not dispose of medicines via household waste or wastewater. Return unused or expired tablets to your pharmacy for safe disposal. This helps protect the environment
If tablets appear discoloured, damaged, or have an unusual odour, do not take them. Consult your pharmacist for replacement. When travelling, keep the medication in your carry-on luggage in its original packaging, along with a copy of your prescription, to avoid issues at customs and to ensure proper storage conditions during transit.
What Does Clopidogrel Orion Contain?
Each Clopidogrel Orion 75 mg film-coated tablet contains clopidogrel hydrogen sulphate equivalent to 75 mg clopidogrel base as the active substance, along with inactive ingredients (excipients) that help form the tablet and its coating.
Understanding the full composition of your medication is important, particularly if you have known allergies or intolerances to specific ingredients. The complete composition of Clopidogrel Orion 75 mg film-coated tablets is as follows:
Active Substance
Each tablet contains clopidogrel hydrogen sulphate corresponding to 75 mg of clopidogrel base. Clopidogrel hydrogen sulphate is the pharmaceutical salt form used to ensure stability and adequate bioavailability of the active substance.
Excipients (Inactive Ingredients)
The tablet core and film-coating contain the following excipients:
- Tablet core: Microcrystalline cellulose, hydroxypropylcellulose (low-substituted), macrogol 6000, hydrogenated castor oil, mannitol
- Film-coating: Hypromellose, titanium dioxide (E171), red iron oxide (E172), triacetin, carnauba wax
The tablets are pink, round, biconvex, film-coated tablets. Patients with known lactose intolerance should note that this formulation does not contain lactose. If you have allergies to any of the listed excipients, consult your doctor or pharmacist before taking this medicine. The film-coating may contain colourings (iron oxide, titanium dioxide) which are approved food-grade additives.
Frequently Asked Questions about Clopidogrel Orion
Clopidogrel Orion is an antiplatelet medicine used to prevent blood clots in adults who have experienced a heart attack (myocardial infarction), ischaemic stroke, or who have peripheral arterial disease. It is also used in combination with aspirin as dual antiplatelet therapy after acute coronary syndrome (unstable angina or NSTEMI) and following coronary stent placement to prevent stent thrombosis. By inhibiting platelet aggregation, it reduces the risk of further cardiovascular events.
The duration depends on your specific condition. After coronary stent placement, you typically need dual antiplatelet therapy (clopidogrel plus aspirin) for 6 to 12 months. After acute coronary syndrome without a stent, treatment is usually up to 12 months. For peripheral arterial disease or prevention after ischaemic stroke, treatment may be continued long-term. Your cardiologist will determine the optimal duration based on your individual risk profile. It is critical that you never stop clopidogrel without consulting your doctor first.
The combination of clopidogrel with omeprazole or esomeprazole is not recommended. These proton pump inhibitors inhibit the CYP2C19 enzyme that is essential for converting clopidogrel into its active form, which can significantly reduce its antiplatelet effectiveness. If you require stomach acid suppression, your doctor may prescribe pantoprazole or lansoprazole instead, as these have minimal impact on CYP2C19 activity. Always discuss any new medications with your doctor.
If you remember within 12 hours of your usual dose time, take the missed dose immediately and continue with your regular schedule. If more than 12 hours have passed, skip the missed dose entirely and take the next dose at the usual time. Never take a double dose to compensate. Setting a daily alarm or using a pill organiser can help you maintain a consistent dosing schedule, which is important for optimal cardiovascular protection.
Clopidogrel should typically be stopped 5 to 7 days before elective surgery to allow platelet function to recover sufficiently and reduce the risk of excessive surgical bleeding. However, this decision must always be made in consultation with your cardiologist and surgeon, particularly if you have a coronary stent. Stopping clopidogrel too early after stent placement can cause life-threatening stent thrombosis. In emergency situations where surgery cannot be delayed, your surgical team will take appropriate precautions to manage bleeding risk.
Clopidogrel Orion is a generic version of clopidogrel, the same active substance found in the original branded product Plavix. Generic medicines must meet strict regulatory standards for bioequivalence, meaning they deliver the same amount of active drug into the bloodstream at the same rate. Clopidogrel Orion has been approved by regulatory authorities and is therapeutically equivalent to Plavix. The main difference is typically the price, with generic versions generally being more affordable.
References
All medical information on this page is based on peer-reviewed clinical studies, international guidelines, and authoritative pharmacological resources. Evidence level: 1A (systematic reviews and meta-analyses of randomised controlled trials).
- CAPRIE Steering Committee. A randomised, blinded, trial of clopidogrel versus aspirin in patients at risk of ischaemic events (CAPRIE). The Lancet. 1996;348(9038):1329-1339.
- Yusuf S, Zhao F, Mehta SR, et al. Effects of clopidogrel in addition to aspirin in patients with acute coronary syndromes without ST-segment elevation (CURE trial). N Engl J Med. 2001;345(7):494-502.
- Sabatine MS, Cannon CP, Gibson CM, et al. Addition of clopidogrel to aspirin and fibrinolytic therapy for myocardial infarction with ST-segment elevation (CLARITY-TIMI 28). N Engl J Med. 2005;352(12):1179-1189.
- Bhatt DL, Scheiman J, Abraham NS, et al. ACCF/ACG/AHA 2008 Expert Consensus Document on reducing the gastrointestinal risks of antiplatelet therapy and NSAID use. J Am Coll Cardiol. 2008;52(18):1502-1517.
- European Society of Cardiology (ESC). 2023 ESC Guidelines for the management of acute coronary syndromes. Eur Heart J. 2023;44(38):3720-3826.
- 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.
- World Health Organization (WHO). Model List of Essential Medicines. 23rd list, 2023.
- European Medicines Agency (EMA). Summary of Product Characteristics - Clopidogrel. Updated 2024.
- National Institute for Health and Care Excellence (NICE). Antiplatelet treatment. Clinical Knowledge Summaries. Updated 2024.
- 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.
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