💊 Allopurinol Tablet 100 mg
📘 Description:
Allopurinol 100 mg tablet is a xanthine oxidase inhibitor used primarily to lower uric acid levels in the blood and urine. It is typically white or off-white in color and taken orally once or multiple times daily as prescribed.
🔬 Nature / Pharmacologic Class:
- Class: Xanthine oxidase inhibitor
- Mechanism of Action:
- Inhibits the enzyme xanthine oxidase, which converts hypoxanthine and xanthine into uric acid
- Reduces production of uric acid, helping to prevent gout and urate nephropathy
🩺 Prescription / Uses:
| Indication | Purpose |
|---|---|
| Gout (chronic treatment) | Prevent attacks by lowering uric acid |
| Hyperuricemia (asymptomatic or symptomatic) | Due to cancer, chemotherapy, or renal disease |
| Prevention of uric acid stones in the kidneys | Especially in patients with recurrent stones |
| Tumor lysis syndrome (TLS) | Prevention during cancer therapy |
| Uric acid nephropathy | Kidney protection in high uric acid states |
✅ Advantages:
- Effective urate-lowering therapy
- Well tolerated for long-term use
- Reduces frequency and severity of gout attacks
- Can be used with colchicine during early treatment phase to prevent flares
- Helps prevent renal complications of hyperuricemia
⚠️ Precautions:
- Start with low dose to prevent acute gout flare
- Hydration is essential to reduce kidney stone risk
- Liver and renal function must be monitored regularly
- Avoid in hypersensitivity syndrome (can be life-threatening)
- Use with caution in elderly and patients with impaired renal function
💊 Dosage & Administration:
| Population | Usual Dose |
|---|---|
| Adults (starting dose) | 100 mg once daily |
| Maintenance dose | 100–300 mg/day (divided doses) |
| Maximum dose | Up to 800 mg/day (based on uric acid level) |
| Renal impairment | Dose adjustment required |
Start low and go slow – high starting doses can precipitate gout attacks.
🔄 Drug Interactions:
- Azathioprine / 6-Mercaptopurine: Requires dose reduction (↑ toxicity risk)
- Diuretics (thiazides): May ↑ risk of allopurinol rash
- Ampicillin/amoxicillin: ↑ skin reaction risk
- Warfarin: May enhance anticoagulant effect
📦 Storage:
- Store at room temperature (15–30°C)
- Keep away from moisture, heat, and light
- Keep out of reach of children
📌 Important Notes:
- Do not use during an acute gout attack (may worsen it)
- Continue taking allopurinol during attacks once chronic therapy has started
- Encourage fluid intake to maintain good urine output
- Monitor uric acid levels, liver and kidney function regularly