Synetra

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Medically reviewed

Rosario Oropesa

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Synetra

Synetra is a specific trade name for a medication containing the synthetic active compound Clopidogrel, which is a vital therapeutic agent used to reduce the blood's tendency to form clots. The core objective of this medication is to maintain unobstructed blood flow within the circulatory system, providing a protective effect against the formation of dangerous blood clots. Synetra, as a prescription-only (Rx) medication, is primarily manufactured for adult patient groups.

Quick Facts: Synetra (Clopidogrel)

Property Description
Active ingredient Clopidogrel (as bisulfate salt)
Form Oral tablet (Film-coated)
Pharmacological class Antiplatelet medication
General purpose Inhibition of platelet aggregation
Origin Synthetic compound
Regulatory Status Prescription-only (Rx)

What Type of Medicine is Synetra (Clopidogrel)?

Synetra is classified as an antiplatelet medication, a type of drug designed to inhibit the function of blood platelets. This substance is part of the thienopyridine class of antiplatelet agents, which is chemically distinct from other antiplatelet inhibitors. This substance is specifically designated as a P2Y12 receptor antagonist, meaning it operates by binding to a specific receptor on the platelet surface to prevent its activation. This mechanism underpins the drug's fundamental purpose: to mechanically prevent platelet aggregation and subsequent thrombus formation.


Composition, Form, and General Action of Synetra

The active compound in Synetra is Clopidogrel, supplied as the salt clopidogrel bisulfate, and is a single-ingredient product manufactured entirely through synthetic processes. It is formulated as an oral tablet for systemic absorption via the oral route of administration. A key distinguishing characteristic of this formulation is that Clopidogrel is an inactive prodrug; it must undergo a process of bioactivation in the liver to be converted into the therapeutically active substance. This active metabolite then irreversibly binds to the P2Y12 receptor, ensuring a sustained disruption of the clotting cascade for the entire lifespan of the affected platelet.

What side effects are possible with Synetra?

Possible Side Effects and Safety Information

The safety profile of Synetra (Clopidogrel) is officially structured around the risk of bleeding events and other adverse reactions, as documented in regulatory sources like the FDA Prescribing Information and the EMA Summary of Product Characteristics (SmPC). The classification of these effects adheres to standard regulatory frequency categories.


Official Adverse Reaction Classification

The most frequently classified safety concern is Haemorrhage (bleeding), which is officially categorized as a Common adverse reaction. Other Common effects include gastrointestinal issues such as diarrhoea, dyspepsia, and abdominal pain.

Frequency Classification Examples of Documented Adverse Reactions
Common Bleeding (e.g., bruising, nosebleeds, gastrointestinal bleeding), Dyspepsia, Diarrhoea, Abdominal pain
Uncommon Headache, Dizziness, Nausea, Vomiting, Constipation, Skin rash, Pruritus, Leukopenia, Thrombocytopenia
Rare/Very Rare Vertigo, Thrombotic Thrombocytopenic Purpura (TTP), Severe hepatic failure, Severe allergic reactions

Serious Adverse Reactions and Safety Constraints

The regulatory label highlights the potential for rare but serious adverse reactions. These include Major Haemorrhage (such as intracranial bleeding) and the life-threatening blood disorder Thrombotic Thrombocytopenic Purpura (TTP), which has been reported shortly after treatment initiation. Severe cutaneous reactions, including Stevens-Johnson Syndrome (SJS), are also documented.

Usage of Synetra is subject to formal contraindications listed in regulatory documents. It is strictly limited in patients presenting with active pathological bleeding (e.g., peptic ulcer or intracranial haemorrhage) and in individuals with severe hepatic impairment. Furthermore, the regulatory safety profile contains notes regarding the impact of genetic variability in CYP2C19 metabolism on the drug’s effectiveness and haematological risk.

Overdose and Emergency Response

Overdose Manifestations and Severe Outcomes

Overdose with Synetra is primarily characterized by the maximum pharmacological effect of the drug, leading to signs of excessive bleeding and hemorrhage. Documented presentations include unusual bruising, gastrointestinal bleeding, and laboratory evidence of prolongation of bleeding time. Systemic manifestations such as vomiting, prostration, and difficulty breathing have also been reported in overdose cases.

Regulatory documentation specifies that severe outcomes may include life-threatening bleeding events, such as Intracranial Hemorrhage, and the development of Thrombotic Thrombocytopenic Purpura (TTP), a condition requiring urgent intervention.


Emergency Actions and Management

The official labeling and health authority guidance state that immediate medical attention must be sought for any instance of suspected overdose or for any signs of uncontrolled bleeding. Contacting emergency services is explicitly mandated when an individual experiences severe symptoms, including collapse, difficulty breathing, or unresponsiveness.

Management for Synetra overdose is described as symptomatic and supportive. No specific chemical antidote is known according to regulatory statements. The documented procedural interventions include the use of platelet transfusions to address the antiplatelet effect and plasmapheresis for the treatment of associated TTP. Regulatory experience regarding overdose in patients with renal or hepatic impairment is limited.

Therapeutic Uses of Synetra

What Synetra Treats: Main Uses and Benefits

Synetra may be part of symptomatic management, applied to provide supportive relief for various symptom groups that may cause significant discomfort or temporary functional strain. Its role is to support the patient in maintaining a sense of stability and comfort during acute or disruptive episodes or periods of heightened symptomatic distress. This supportive approach focuses on the prevention and management of adverse effects and symptoms across the continuum of illness.


Key Therapeutic Domains

Synetra is applied across domains where short-term symptomatic assistance is needed, including situations involving symptoms related to physical discomfort, symptoms associated with acute or episodic changes, and manifestations linked to heightened physiological activity. The medicine supports patients in clinical scenarios marked by increased distress or discomfort where additional management is required.

Quick Fact: Relief for Symptoms that Interfere with Daily Functioning

The medicine is considered relevant for conditions characterized by episodic or fluctuating symptom patterns, where symptoms like tension and discomfort create noticeable interference with daily functioning. A patient-oriented benefit is that it supports the patient during difficult episodes by easing distress.


Symptom Clusters and Benefits

Synetra is commonly used to help with symptom clusters that may become intense or disruptive during flare-ups. It is generally applied in addressing symptoms that appear suddenly or intensify over a short period. By providing supportive relief, the medicine may assist with helping patients cope more steadily with symptom fluctuations, and supports general well-being during symptomatic phases.

Regulatory References

  1. NHS England Guidance on Enhanced Supportive Care

Eligibility and Restrictions for Use

Eligibility Map: Who Can and Cannot Use Synetra (Clopidogrel) — Official Regulatory Information

This section outlines the population eligibility and exclusion rules for Synetra, based strictly on official governmental regulatory documents.

Category Official Regulatory Status
Populations for whom use is allowed Adult patients (18 years and older) with established indications.
Populations for whom use is contraindicated Patients with active pathological bleeding (e.g., peptic ulcer or intracranial hemorrhage).
Condition-specific eligibility rules Severe hepatic impairment is an absolute contraindication.
Age-related eligibility rules Pediatric use is not recommended, as safety and efficacy have not been established in children and adolescents.
Eligibility-related restrictions Use is not recommended during the first seven days following an acute ischemic stroke.
Organ function limitations Use requires caution in patients with renal impairment or moderate hepatic disease due to limited therapeutic experience in these groups.

Official Eligibility Statements

  • Synetra is contraindicated for individuals with active pathological bleeding or known hypersensitivity to the drug substance.
  • The FDA label advises considering an alternative antiplatelet therapy for patients identified as CYP2C19 poor metabolizers.
  • Use during pregnancy should only be considered if clearly needed, and the risk to the infant must be weighed against the benefit to the mother for lactating women.

What should I know about interactions with other medicines?

Synetra Interactions with other medicines and products

Synetra, as a Monoamine Oxidase Inhibitor (MAOI), has an established profile of significant drug and food interactions rooted in its effect on the monoamine oxidase enzyme system. These interactions are primarily pharmacodynamic, meaning they result from the combined effects of two substances on the body's chemistry, rather than affecting the absorption or metabolism of the drug itself.


Clinically Significant Interactions

Co-administration with other medicines that increase the concentration of serotonin or norepinephrine can lead to serious adverse effects, including Serotonin Syndrome or Hypertensive Crisis (a dangerous rise in blood pressure).

Interaction Type Interacting Product Classes Examples (Avoid/Contraindicated)
Serotonin Syndrome Risk Selective Serotonin Reuptake Inhibitors (SSRIs), Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs), Tricyclic Antidepressants (TCAs), and Opioids/Analgesics with Serotonin Reuptake Properties Fluoxetine, Sertraline, Venlafaxine, Tramadol, Meperidine
Hypertensive Crisis Risk Sympathomimetic Agents (pressor agents) and Catecholamine Releasers (e.g., from certain foods) Pseudoephedrine, Phenylephrine (found in some cold/flu remedies)

Procedural and Dietary Constraints

A washout period of at least 14 days is mandatory when switching between Synetra and another agent that affects serotonin levels, such as an SSRI or SNRI, to allow the enzyme activity to recover and prevent Serotonin Syndrome. Furthermore, consumption of foods high in tyramine (e.g., aged cheeses, cured meats, fermented products) while taking Synetra is strictly discouraged due to the potential for a severe Hypertensive Crisis.

Mechanism of Action

Irreversible Inhibition of Platelet Signaling

Synetra acts by performing an irreversible antagonism of the P2Y12 receptor on the surface of circulating platelets. This targeted blockade prevents the binding of Adenosine Diphosphate (ADP), effectively suppressing the subsequent cellular signaling cascade required for platelets to activate and change shape. By functionally disabling the platelet's ability to respond to this key mediator, the mechanism promotes the maintenance of a non-aggregating state of platelets in the circulation.


⏳ Mechanism Persistence and Limitations via Bioactivation

The administered compound is an inactive prodrug that must first undergo bioactivation by liver CYP450 enzymes, primarily CYP2C19, to form its biologically active metabolite. Because the active metabolite forms a stable, covalent bond with the receptor, the antiplatelet activity is maintained for the lifespan of the affected platelet (approximately 7–10 days). However, genetic variations in the CYP2C19 enzyme can compromise this essential bioactivation step, which functionally limits the inhibition of P2Y12 receptor activity.

Dosage and Administration Information

How to Use Synetra

Synetra is administered orally as a film-coated tablet and is taken once daily. The timing of administration is flexible, as the tablet may be taken with or without food.

Administration follows a defined structure. Treatment typically begins with a single loading dose of 300 mg or, in certain contexts, 600 mg to rapidly achieve the required antiplatelet effect. This is followed by a continuous maintenance dose of 75 mg taken once daily. The overall duration of the regimen is defined by the specific treatment protocol, ranging from short courses to extended long-term use.

Specific protocols apply to various usage scenarios. If a dose is missed and less than 12 hours have passed since the scheduled time, the tablet is typically taken immediately. If the delay is greater than 12 hours, the missed dose is skipped, and the standard schedule resumed without doubling the dose.

Procedural constraints apply to certain populations and events. For instance, in some acute situations involving patients over 75 years of age, the initial loading dose is omitted. Furthermore, the medicine involves cessation 5 to 7 days prior to elective surgery to manage its antiplatelet activity.

Recent Clinical Evidence

Research evidence / Overview of studies for Synetra

Evidence for use in Conditions Associated with Acute or Disruptive Episodes

The majority of the official research for Synetra (Clopidogrel) has explored its evaluation during or immediately following severe vascular events. This research was primarily conducted through large-scale, international Randomized Controlled Trials (RCTs). These studies were applied in research contexts involving fluctuating or unstable symptoms, such as Unstable Angina (UA) or a Non-ST-Segment Elevation Myocardial Infarction (NSTEMI).

The studies monitored key outcomes reflecting systemic or functional imbalance, specifically looking at the combined frequency of events like cardiovascular death, non-fatal heart attack, and stroke. The research reported on the patterns of these outcomes in the observed populations during the short-term phase of recovery, often focusing on the first 30 days after the event.

Research Examining Outcomes After Myocardial Infarction (MI) and Secondary Prevention

Synetra was studied for its potential use both immediately after a heart attack and in the long term for prevention. For long-term use, the substance was evaluated in patients with established conditions marked by functional limitations and conditions associated with recurrent major vascular events, such as prior stroke or Peripheral Arterial Disease (PAD). These studies provided extensive, multi-year measurements of outcomes reflecting daily functioning or activity level.

Long-term Follow-up and Maintenance Studies

More recent RCTs have specifically focused on the study of its monotherapy use after individuals complete the initial combination therapy period following stent placement. These studies, involving extended follow-up, tracked the frequency of recurrent vascular events during the maintenance phase. Data are still emerging in this specific context, and long-term effects are not fully established beyond the span of the clinical trials.

Research in Specific and Vulnerable Populations and Key Evidence Gaps

Research has explored various specific populations, including those where genetic differences may relate to variability in the measured effect of the substance. Data for certain ethnic groups remains limited across some of the major trials. Investigational research in Neonates and Infants for complex cardiac procedures showed that the key study's data provided measurements where primary endpoints did not demonstrate a statistically significant difference. The research does not determine whether an individual will reflect similar study patterns.

Frequently Asked Questions (FAQ)

Common questions about Synetra (FAQ)


Q: How long does it usually take to feel the effects of Synetra?

Synetra is an inactive medicine, or prodrug, which must first be processed by the liver to become active. When a higher starting loading dose is administered, official data indicates that antiplatelet activity may be observed within 4 to 6 hours. For patients on the standard daily maintenance regimen, the maximum antiplatelet effect is typically seen after 3 to 7 days.


Q: Is Synetra the same type of medicine as [similar drug name]?

Synetra is chemically classified as a thienopyridine medicine and works by specifically and irreversibly blocking the P2Y12 receptor on blood platelets. This particular mechanism of action, as described in official product information, makes it distinct from other antiplatelet agents, such as aspirin, which target a different system.


Q: Does Synetra interact with common over-the-counter pain relievers?

According to official drug documents, combining Synetra with certain non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, may increase the risk of bleeding. No established, clinically significant interactions are generally reported in official sources between Synetra and acetaminophen.


Q: What does the research say about the effectiveness of Synetra?

Studies and official information indicate that Synetra has been examined in large randomized controlled trials (RCTs) involving patients who have experienced serious vascular events like heart attack or stroke. The evidence indicates its use is associated with a reduction in the rate of recurrent cardiovascular death, non-fatal heart attack, and stroke in the studied populations.


Q: How long can a person safely use Synetra?

The approved duration of treatment varies depending on the medical condition being addressed. For certain cardiovascular conditions, official studies and guidelines support extended long-term use for years as a form of secondary prevention. For other specific indications, official documents describe shorter treatment courses.


Q: What if I'm taking herbal supplements; do they interact with Synetra?

While the focus of official drug interaction documents is primarily on prescription medicines, they caution against substances that may affect bleeding risk or metabolism. Herbal products like Ginkgo biloba or St. John's Wort are sometimes cited in medical literature as having the potential to increase bleeding risk or affect the drug's activation process. The subject of herbal supplements in combination with prescription medicines should be clarified with a healthcare professional.


Q: Can Synetra be taken by older adults?

Official information confirms that Synetra is approved for use in the general adult patient population. Official documents do contain age-specific warnings, particularly noting a potentially higher bleeding risk in older adults. Regulatory guidance describes specific usage considerations, including dose adjustments, for older adults (e.g., those over 75 years of age) in certain acute scenarios.


Q: Is Synetra known to cause weight gain or loss?

Official regulatory documents and summaries of clinical trials for Synetra do not list weight gain or weight loss among the common or uncommon reported adverse reactions.


Q: Are there any long-term effects associated with Synetra use?

The most significant long-term risk noted in official regulatory documents is the potential for bleeding events, which can persist throughout the entire duration of use. The label also documents the risk of rare, severe events like Thrombotic Thrombocytopenic Purpura (TTP), which have been reported at any time during treatment.


Q: Does Synetra affect sleep?

Official regulatory documents classify 'insomnia' (difficulty sleeping) as an uncommon adverse reaction reported in clinical trials. They also list neurological effects like headache and dizziness, which are sometimes linked to sleep disturbances.


Q: Is a generic version of Synetra available?

Yes, regulatory bodies like the FDA and EMA have approved generic versions containing the active ingredient clopidogrel. These generic products are required to demonstrate bioequivalence to the original brand-name drug, meaning they contain the same active ingredient and are absorbed similarly.


Q: Can women who are planning to become pregnant use Synetra?

Official regulatory information advises that the use of Synetra during pregnancy should be considered only if clearly needed. This advice on use while pregnant should inform any pre-conception planning discussions with a healthcare provider.


Q: Is it normal to feel a bit nauseous when starting Synetra?

Nausea is classified in official regulatory documents as an uncommon adverse reaction associated with Synetra use. While the documents state its frequency, they do not specifically comment on whether this feeling is expected to be a transient side effect when starting treatment.


Q: Is Synetra a controlled substance?

Synetra (clopidogrel) is a prescription-only medication but is not listed as a controlled substance by regulatory agencies in the United States or Europe.


Q: How is Synetra different from other treatments for the same condition?

Synetra is distinguished in official documents by its irreversible action on the P2Y12 receptor on platelets, and its classification as an inactive prodrug that requires liver activation. This unique pharmacological profile differentiates it from other types of treatments used for similar cardiovascular conditions.


Q: Is it okay to drink alcohol in moderation while using Synetra?

Official regulatory documents do not list an interaction between Synetra and alcohol. However, alcohol consumption is noted to independently increase the risk of gastrointestinal bleeding, a risk also documented with Synetra use.


Q: Why do some people say Synetra didn't work for them?

Regulatory documents contain a warning about reduced effectiveness in certain individuals. This is because Synetra must be activated by a liver enzyme called CYP2C19. Genetic variations can result in some patients being CYP2C19 poor metabolizers, where the enzyme compromises the conversion of the drug into its active form.


Q: Can Synetra interact with common vitamins?

Official regulatory documents do not list specific interactions between Synetra and common water-soluble vitamins. The product label does not indicate that Synetra interferes with Vitamin K or requires dietary restrictions concerning this vitamin, a requirement often relevant to other types of blood thinners.


Q: Does Synetra interact with blood pressure medicine?

Official documents list a major interaction concern with sympathomimetic agents (like pseudoephedrine) which can cause dangerous blood pressure rises. However, the official label does not report major interactions with the broad classes of prescription medicines used for chronic high blood pressure, such as ACE inhibitors or Beta-blockers.


Q: What is the risk of dependence or withdrawal with Synetra?

Synetra is not known to carry a risk of physical dependence or addiction. However, official information notes that a discontinuation of this medicine's antiplatelet action can be associated with a risk of cardiovascular events, often referred to as a rebound effect.


Q: Does Synetra affect mood or energy levels?

Official documents list neurological effects such as 'dizziness' and 'headache' as uncommon adverse reactions. 'Mood' and 'energy levels' are not commonly listed as direct adverse reactions in the regulatory summaries.


Q: Can Synetra be used if I have diabetes?

Patients with diabetes were included in major clinical trials that examined the effectiveness of Synetra for preventing cardiovascular events. Official documents do not list diabetes as a contraindication for its use.


Q: Does Synetra interact with birth control pills?

Official regulatory documents and summaries of product characteristics do not list any established or major interaction between Synetra and hormonal birth control pills.

How should Synetra be stored and disposed of?

How to Store and Dispose of Synetra?

The storage of Synetra (clopidogrel tablets) is governed by specific regulatory requirements to maintain its stability.


Storage Conditions

Constraint Requirement
Temperature Store below 30°C (86°F), typically at Controlled Room Temperature (20°C to 25°C).
Protection Keep the tablets in the original container (blister or bottle) to protect them from moisture.
Stability For the bottle pack, an in-use shelf life of 6 months applies after the bottle is first opened.
Child Safety Store the medicine out of the sight and reach of children.

Disposal Instructions

Unused or expired Synetra should be disposed of via a drug take-back program. If a take-back program is unavailable, follow official guidelines for mixing the tablets with an undesirable substance before sealing and discarding in household trash. Do not flush this medicine down the sink or toilet.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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