Zyloprim (allopurinol) is a xanthine oxidase inhibitor prescribed for the long-term management of chronic gout and conditions involving elevated uric acid levels, such as hyperuricemia. It functions by reducing the production of uric acid in the body, thereby preventing the formation of urate crystals that deposit in joints and tissues. This medication is not intended for the treatment of acute gout attacks but serves as a foundational prophylactic therapy to reduce the frequency and severity of future episodes. Proper adherence to dosing under medical supervision is essential for optimal therapeutic outcomes and minimizing potential adverse effects.

Features

• Active ingredient: Allopurinol
• Available in 100 mg and 300 mg tablet strengths
• Prescription-only medication
• Generic and brand-name formulations available
• Oral administration
• Requires routine monitoring of serum uric acid levels and renal function

Benefits

• Significantly reduces serum uric acid concentrations
• Prevents formation of new gouty tophi and renal stones
• Decreases frequency and intensity of acute gout flares over time
• May help prevent joint damage and chronic arthropathy associated with gout
• Reduces risk of uric acid nephropathy
• Supports long-term management of hyperuricemia

Common use

Zyloprim is primarily indicated for the management of chronic gout, either tophaceous or non-tophaceous, and for the treatment of hyperuricemia secondary to other conditions, including certain malignancies and their treatments. It is also used in patients with recurrent uric acid stone formation and those with Lesch-Nyhan syndrome. The medication is not appropriate for asymptomatic hyperuricemia unless the patient is undergoing cancer chemotherapy with a high risk of tumor lysis syndrome.

Dosage and direction

Dosage must be individualized based on serum uric acid levels, renal function, and the severity of the condition. The typical starting dose for adults is 100-300 mg daily, which may be increased weekly until desired uric acid levels are achieved (usually below 6 mg/dL). Maximum daily dose is 800 mg, though doses above 300 mg should be divided. For patients with renal impairment, dosage adjustments are necessary—often starting with 100 mg daily or alternate-day dosing. Tablets should be taken with plenty of water, preferably after meals to minimize gastric upset. Regular monitoring of uric acid levels, renal function, and liver enzymes is recommended during therapy.

Precautions

Patients should maintain adequate hydration (2-3 liters daily) to prevent uric acid stone formation. Regular blood tests are essential to monitor for hematological, hepatic, and renal abnormalities. Use with caution in patients with pre-existing hepatic or renal impairment. Patients should be advised that acute gout attacks may increase during initial therapy; concurrent prophylactic NSAID or colchicine therapy is often recommended during the first 3-6 months of treatment. Caution is advised when operating machinery until the patient’s response to therapy is known.

Contraindications

Zyloprim is contraindicated in patients with a history of hypersensitivity to allopurinol or any component of the formulation. It should not be initiated during an acute gout attack. Contraindicated in patients who have experienced severe skin reactions (such as Stevens-Johnson syndrome or toxic epidermal necrolysis) with previous allopurinol use. Not recommended for use in children except those with hyperuricemia secondary to malignancy.

Possible side effect

Common side effects include skin rash (discontinue immediately if rash appears), nausea, vomiting, diarrhea, and drowsiness. Less frequent adverse reactions include elevated liver enzymes, leukopenia, thrombocytopenia, and peripheral neuropathy. Serious but rare side effects include severe skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis), hepatitis, vasculitis, and eosinophilia. Allopurinol hypersensitivity syndrome, though uncommon, represents a potentially fatal reaction characterized by fever, rash, eosinophilia, hepatitis, and renal impairment.

Drug interaction

Zyloprim interacts significantly with azathioprine and mercaptopurine, increasing their toxicity—dosage reduction of these medications is mandatory. Concurrent use with ampicillin/amoxicillin increases the risk of skin rash. May potentiate the effects of oral anticoagulants (warfarin) and theophylline. Diuretics, especially thiazides, may increase the risk of hypersensitivity reactions. Caution is advised when co-administering with ACE inhibitors due to increased risk of hypersensitivity reactions.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next scheduled dose. Do not double the dose to make up for a missed one. Consistent daily administration is important for maintaining stable uric acid levels. Patients should establish a routine to support adherence, such as taking the medication at the same time each day.

Overdose

Symptoms of overdose may include nausea, vomiting, diarrhea, and dizziness. In severe cases, acute renal failure may occur. Management involves supportive care, including gastric lavage if ingestion was recent and adequate hydration to promote renal excretion. Hemodialysis may be effective in removing allopurinol and its primary metabolite, oxypurinol. There is no specific antidote; treatment should be symptomatic and supportive.

Storage

Store at room temperature (15-30°C or 59-86°F) in a dry place, protected from light and moisture. Keep in the original container with the lid tightly closed. Do not store in bathroom cabinets where humidity levels may fluctuate. Keep out of reach of children and pets. Do not use after the expiration date printed on the packaging.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Zyloprim is a prescription medication that should only be used under the supervision of a qualified healthcare professional. Dosage, indications, and precautions may vary based on individual patient factors. Always consult with a physician or pharmacist for personalized medical advice and report any adverse reactions promptly. Never adjust dosage or discontinue medication without medical guidance.

Reviews

Clinical studies and patient reports consistently demonstrate Zyloprim’s efficacy in reducing serum uric acid levels and preventing gout attacks when used appropriately long-term. Many patients experience significant reduction in gout flare frequency within 6-12 months of consistent use. Some users report gastrointestinal discomfort during initial treatment, which often resolves with continued use or dose adjustment. The medication receives particular praise from patients who had previously experienced frequent, debilitating gout attacks, with many describing life-changing improvements in quality of life. Medical professionals emphasize the importance of patience during the initial treatment period and adherence to monitoring protocols.