Ibustrin (Indobufen)

Indobufen is used to inhibit platelet‑mediated clot formation in arterial vascular conditions.

• Arterial thrombosis: reduces incidence of clot formation in arteries.
• Myocardial infarction (secondary prevention): lowers risk of recurrent heart attacks.
• Stroke prevention: decreases likelihood of ischemic stroke in at‑risk patients.
• Peripheral arterial disease: improves blood flow by preventing arterial occlusion.

• Indobufen reversibly inhibits platelet cyclooxygenase‑1 (COX‑1), which blocks the conversion of arachidonic acid to thromboxane A₂. By reducing thromboxane A₂ synthesis, the drug diminishes platelet activation and aggregation, thereby preventing the formation of arterial thrombi without permanently altering platelet function. The inhibition is dose‑dependent and reversible, allowing normal platelet function to resume after the drug is cleared. Indobufen’s selectivity for COX‑1 over COX‑2 contributes to a lower risk of gastrointestinal side effects compared with non‑selective NSAIDs.

Indobufen may be associated with a range of adverse reactions, which are categorised by frequency and severity.

Common Side Effects

• Dyspepsia: upper abdominal discomfort or pain.
• Nausea: feeling of sickness.
• Headache: mild to moderate head pain.
• Dizziness: sensation of light‑headedness.
• Rash: mild skin irritation.

Serious or Rare Side Effects

• Severe bleeding: gastrointestinal or intracranial hemorrhage.
• Thrombocytopenia: marked reduction in platelet count.
• Hepatic dysfunction: elevated liver enzymes or hepatitis.
• Anaphylaxis: life‑threatening allergic reaction.
• Neutropenia: low neutrophil count increasing infection risk.

When prescribing Indobufen, clinicians should consider several precautionary measures to minimise risk.

• Assess bleeding risk: evaluate history of ulcers or hemorrhage before initiating therapy.
• Monitor liver function: perform baseline and periodic liver enzyme tests.
• Use caution in renal impairment: adjust dose or monitor renal parameters in patients with reduced kidney function.
• Avoid in known hypersensitivity: discontinue if allergic reactions occur.
• Limit concomitant antiplatelet use: combine with other agents only under specialist guidance.
• Store at room temperature: keep in original packaging, protect from moisture and direct sunlight.

Indobufen can interact with other medicines, affecting its antiplatelet activity or bleeding risk.

Major Interactions (Avoid)

• Aspirin: additive antiplatelet effect may increase bleeding.
• Other antiplatelet agents (e.g., clopidogrel, ticagrelor): heightened risk of severe hemorrhage.
• Anticoagulants (warfarin, direct oral anticoagulants): synergistic anticoagulation leading to major bleeding.
• Non‑steroidal anti‑inflammatory drugs (NSAIDs): combined effect on platelet function and gastrointestinal mucosa.
• Selective serotonin reuptake inhibitors (SSRIs): may impair platelet aggregation and raise bleeding risk.

Moderate Interactions (Monitor Closely)

• CYP2C9 inhibitors (e.g., fluconazole, amiodarone): may increase indobufen plasma levels.
• CYP2C9 inducers (e.g., rifampicin, carbamazepine): may reduce therapeutic effect.
• ACE inhibitors: potential for additive hypotensive effect.
• Diuretics: monitor electrolytes and renal function when used together.
• Oral contraceptives: may slightly increase thrombotic risk; monitor closely.