Allopurinol: Uses, Dosage, Precautions, and Safety Guide

What Is Allopurinol?

Allopurinol is a prescription medication used to reduce high levels of uric acid in the blood. It is commonly prescribed for:

• Gout

• Kidney stones caused by uric acid

• Patients undergoing chemotherapy, where rapid cell breakdown increases uric acid levels

By lowering uric acid production, Allopurinol helps prevent painful flare-ups and long-term complications related to excess urate.

Classification and How Allopurinol Works

Allopurinol belongs to a class of medications known as xanthine oxidase inhibitors.
It works by blocking xanthine oxidase, the enzyme responsible for converting hypoxanthine and xanthine into uric acid.

By reducing this enzyme’s activity, Allopurinol helps:

• Lower uric acid levels in the blood

• Prevent gout attacks

• Reduce the risk of uric acid kidney stones

• Support patients with cancer therapies that may trigger high uric acid levels

Storage Instructions

Store Allopurinol:

• At room temperature

• Away from moisture and direct heat

• In a secure location out of reach of children

How to Take Allopurinol

• Take the medication exactly as prescribed by your doctor.

• It is taken by mouth, typically once daily.

• Drinking plenty of water is often recommended to help prevent kidney stones.

• Your doctor may order periodic blood tests to monitor uric acid levels and organ function.

Dosage

Dosage varies based on medical condition, kidney function, and treatment goals.
Common doses include 100 mg or 200 mg daily, though some patients may require adjustments.

Always follow your doctor’s specific instructions.

Overdose

If an overdose is suspected, seek immediate medical assistance.

Missed Dose

• Take the missed dose as soon as you remember.

• If it is close to your next scheduled dose, skip the missed dose.

• Do not double dose.

Warnings and Precautions

Allopurinol may increase susceptibility to:

• Infections

• Bleeding

• Severe skin reactions (rare but serious)

Important precautions:

• Regular blood tests may be required to monitor blood counts and organ function.

• Avoid situations where you might get injured or exposed to infectious illnesses.

• Inform your doctor if you experience unusual fatigue, fever, or signs of infection.

• Let your doctor know about any kidney, liver, or heart conditions.

Possible Side Effects

Common Effects

• Stomach upset (nausea, vomiting, or diarrhea)

• Abdominal pain

• Joint pain or stiffness

• Skin rashes or hives

Serious Effects (Seek Medical Help)

• Unusual bruising or bleeding

• Fever or signs of infection

• Severe skin reactions (e.g., blistering, peeling)

• Persistent sore throat

• Signs of liver issues (dark urine, yellowing of skin/eyes)

When Allopurinol Should Not Be Used

Allopurinol may not be suitable for individuals with:

• Known allergy to Allopurinol

• Severe kidney or liver disease

• Certain heart conditions

• Blood disorders or bone marrow suppression

Always discuss your full medical history with your doctor before starting treatment.

How Long Should You Take Allopurinol?

Take Allopurinol for the duration prescribed by your doctor.
Stopping the medication too early can lead to uncontrolled uric acid levels and may trigger gout attacks or complications.

Never change your dose without consulting your healthcare provider.