Milapur (Allopurinol)

Allopurinol acts on purine metabolism to reduce uric acid levels, addressing conditions linked to hyperuricemia.

• Gout: lowers serum uric acid to prevent acute gout attacks and reduce tophi formation.
• Hyperuricemia: maintains target uric acid concentrations to avoid crystal deposition.
• Tumor lysis syndrome prophylaxis: reduces uric acid surge during rapid tumor cell breakdown in oncology patients.

• Allopurinol is a structural analogue of hypoxanthine that competitively inhibits the enzyme xanthine oxidase. By blocking this key step in purine catabolism, the conversion of hypoxanthine to xanthine and xanthine to uric acid is reduced, leading to decreased production of uric acid and lower serum urate concentrations. The inhibition is reversible and persists as the active metabolite oxypurinol accumulates, providing sustained urate‑lowering effect during chronic therapy.

Allopurinol may be associated with a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Rash: mild skin eruption or itching.
• Nausea: feeling of queasiness, sometimes with vomiting.
• Diarrhea: loose stools, occasional abdominal cramping.

Serious or Rare Side Effects

• Stevens‑Johnson syndrome or toxic epidermal necrolysis: severe skin detachment.
• Hepatic failure: marked elevation of liver enzymes with jaundice.
• Blood dyscrasias: agranulocytosis, aplastic anemia, or thrombocytopenia.

When prescribing Milapur, several safety considerations should be observed.

• Renal function: dose adjustment required in patients with impaired renal clearance.
• Hypersensitivity: discontinue if any allergic reaction such as rash or swelling occurs.
• Pregnancy: use only if potential benefit justifies potential risk to the fetus.
• Drug interactions: monitor closely when co‑administered with azathioprine, mercaptopurine, or warfarin.
• Gout flare prophylaxis: consider initiating anti‑inflammatory therapy to prevent initial gout attacks.
• Store at ambient temperature below 25°C: keep in the original container, protect from moisture and direct sunlight.

Allopurinol can interact with several medicines, requiring attention to avoid adverse outcomes.

Major Interactions (Avoid)

• Azathioprine: increased risk of bone marrow suppression.
• Mercaptopurine: heightened toxicity due to overlapping metabolic pathways.
• Warfarin: potentiation of anticoagulant effect leading to elevated INR.

Moderate Interactions (Monitor Closely)

• Thiazide diuretics: may reduce uric acid excretion, diminishing efficacy.
• ACE inhibitors: possible alteration of uric acid handling.
• NSAIDs: can mask symptoms of gout flare, complicating clinical assessment.