Obsagrel (clopidogrel bisulphate + aspirin): Uses, Dosage & Side Effects

What it's for (Indications)

This medication, combining clopidogrel bisulphate and aspirin, is primarily indicated for the prevention of atherothrombotic events in adult patients presenting with acute coronary syndrome (ACS).
This encompasses patients experiencing unstable angina or non-ST-segment elevation myocardial infarction (NSTEMI), including those who are medically managed and those undergoing percutaneous coronary intervention (PCI) with or without stent placement, as well as patients with ST-segment elevation myocardial infarction (STEMI) who are medically managed or undergoing primary PCI.
Furthermore, it is prescribed for patients with a history of recent myocardial infarction, recent ischemic stroke, or established peripheral arterial disease, particularly when there is a high risk of recurrent ischemic events and dual antiplatelet therapy is deemed necessary by a healthcare professional.
The synergistic action aims to reduce the incidence of cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke.

Dosage Information

Type	Guideline
Standard	The dosage regimen for clopidogrel bisulphate and aspirin combination therapy is highly individualized and depends on the specific clinical indication and patient characteristics, always determined by a treating physician. For patients with acute coronary syndrome (ACS), a common approach involves an initial loading dose of clopidogrel (e.g., 300 mg or 600 mg) combined with aspirin, followed by a maintenance dose. A typical maintenance dose involves 75 mg of clopidogrel once daily, co-administered with a daily dose of aspirin, usually ranging from 75 mg to 150 mg. It is crucial to adhere strictly to the prescribed dosage and duration of therapy, which can extend for several months to a year or more, depending on the patient's risk profile and the nature of their cardiovascular event. Patients should not discontinue this medication without consulting their physician due to the increased risk of thrombotic events.

Type

Guideline

Standard

The dosage regimen for clopidogrel bisulphate and aspirin combination therapy is highly individualized and depends on the specific clinical indication and patient characteristics, always determined by a treating physician. For patients with acute coronary syndrome (ACS), a common approach involves an initial loading dose of clopidogrel (e.g., 300 mg or 600 mg) combined with aspirin, followed by a maintenance dose. A typical maintenance dose involves 75 mg of clopidogrel once daily, co-administered with a daily dose of aspirin, usually ranging from 75 mg to 150 mg. It is crucial to adhere strictly to the prescribed dosage and duration of therapy, which can extend for several months to a year or more, depending on the patient's risk profile and the nature of their cardiovascular event. Patients should not discontinue this medication without consulting their physician due to the increased risk of thrombotic events.

Safety & Warnings

Common Side Effects

The combination of clopidogrel and aspirin significantly increases the risk of bleeding events, which is the most common and clinically significant side effect.
These bleeding events can range from minor occurrences such as bruising, epistaxis (nosebleeds), or gastrointestinal bleeding (e.
g.
, melena, hematemesis), to more severe and potentially life-threatening hemorrhages, including intracranial hemorrhage.
Other reported side effects include dyspepsia, abdominal pain, diarrhea, and nausea.
Skin reactions such as rash, pruritus, and urticaria may also occur.
Rarely, more severe adverse reactions such as thrombotic thrombocytopenic purpura (TTP) associated with clopidogrel, or hypersensitivity reactions, including angioedema or bronchospasm, can manifest.
Patients should be educated on the signs of bleeding and instructed to seek immediate medical attention if significant bleeding occurs.

Serious Warnings

Black Box Warning: **WARNING: DIMINISHED ANTIPLATELET EFFECT IN PATIENTS WITH TWO LOSS-OF-FUNCTION ALLELES OF THE CYP2C19 GENE** The effectiveness of clopidogrel depends on its activation to an active metabolite by the cytochrome P450 (CYP2C19) enzyme. Patients who are CYP2C19 poor metabolizers, possessing two loss-of-function alleles for the CYP2C19 gene, exhibit diminished platelet inhibition and are at higher risk for cardiovascular events following a myocardial infarction or stent thrombosis compared to patients with normal CYP2C19 function. Tests are available to identify patients who are CYP2C19 poor metabolizers. Healthcare professionals should consider alternative treatment strategies or adjust clopidogrel dosing for patients identified as CYP2C19 poor metabolizers, especially in the context of Acute Coronary Syndrome or Percutaneous Coronary Intervention, as this genetic variation significantly impacts the drug's therapeutic efficacy and patient outcomes. The decision to use clopidogrel in poor metabolizers should be carefully weighed against the potential for reduced antiplatelet benefit and increased risk of thrombotic events.
This medication carries several important warnings.
The most prominent is the increased risk of bleeding.
Patients should be carefully monitored for signs of bleeding, especially those with pre-existing conditions that increase bleeding risk, such as peptic ulcer disease, recent surgery, or concurrent use of other agents affecting hemostasis.
It is generally recommended to discontinue this combination therapy 5 to 7 days prior to elective surgery due to the enhanced risk of perioperative bleeding, though this decision should be made in consultation with the patient's surgeon and cardiologist.
Thrombotic thrombocytopenic purpura (TTP), a rare but serious and potentially fatal condition, has been reported with clopidogrel.
Patients should be promptly evaluated if TTP is suspected, characterized by fever, weakness, extreme pallor, purpura, and neurological changes.
Caution is also advised in patients with severe hepatic or renal impairment due to altered drug metabolism and excretion.

How it Works (Mechanism of Action)

The therapeutic efficacy of this combination product stems from the synergistic antiplatelet actions of its two components: clopidogrel and aspirin. Clopidogrel, a thienopyridine prodrug, is metabolized in the liver to its active form, which then irreversibly binds to the P2Y12 adenosine diphosphate (ADP) receptor on the surface of platelets. This binding selectively inhibits ADP-induced platelet activation and aggregation, a crucial step in thrombus formation. Aspirin (acetylsalicylic acid) acts by irreversibly inhibiting cyclooxygenase-1 (COX-1) enzyme primarily within platelets. This inhibition prevents the synthesis of thromboxane A2 (TXA2), a potent vasoconstrictor and inducer of platelet aggregation. By targeting two distinct pathways involved in platelet activation, the combination therapy provides a more potent and comprehensive antiplatelet effect, thereby reducing the risk of ischemic events.

Commercial Brands (Alternatives)

Lowplat Plus 150mg

Brand

Pharm Evo

Clopidogrel Bisulphate (75mg) + Aspirin (150mg)

Lowplat Plus

Brand

Pharm Evo

Clopidogrel Bisulphate (75mg) + Aspirin (75mg)

Ascard Plus

Brand

Atco

Clopidogrel Bisulphate (81mg) + Aspirin (75mg)

Pidogrel-Ap

Brand

Highnoon

Clopidogrel Bisulphate (75mg) + Aspirin (75mg)