Zyloprim, with the active ingredient allopurinol, is a xanthine oxidase inhibitor prescribed for the long-term management of gout and conditions marked by 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, causing painful gout attacks and potential kidney damage. This medication is a cornerstone of urate-lowering therapy, aimed not only at treating acute episodes but, more importantly, at providing prophylactic management to prevent future occurrences and complications. Proper use under medical supervision can significantly improve quality of life for patients suffering from these chronic conditions.

Features

• Active Pharmaceutical Ingredient: Allopurinol.
• Available in tablet formulations, commonly 100 mg and 300 mg strengths.
• Mechanism of Action: Potent inhibitor of the enzyme xanthine oxidase.
• Reduces the endogenous production of uric acid, rather than increasing its excretion.
• Designed for oral administration, typically once daily after initial titration.

Benefits

• Prevents the formation of new uric acid crystals in joints and soft tissues.
• Significantly reduces the frequency and severity of acute gout attacks over time.
• Lowers the risk of chronic complications associated with hyperuricemia, including tophi formation and uric acid nephrolithiasis (kidney stones).
• Helps protect renal function in patients with conditions that cause excessive uric acid production, such as during chemotherapy for certain malignancies.
• Provides a predictable and manageable long-term treatment strategy for chronic gout.
• Contributes to improved joint health and overall mobility by addressing the underlying cause of gout inflammation.

Common use

Zyloprim (allopurinol) is primarily indicated for the management of:

• Chronic gout and gouty arthritis.
• Recurrent uric acid kidney stones.
• Hyperuricemia secondary to blood cancers (e.g., leukemias, lymphomas) and their treatments.
• Hyperuricemia in patients with certain enzyme deficiencies, such as Lesch-Nyhan syndrome.

It is not typically used for the immediate relief of an acute gout attack, as it may initially precipitate or worsen symptoms. Its role is prophylactic, focusing on long-term control.

Dosage and direction

Dosage is highly individualized based on the severity of the condition, uric acid levels, and renal function. The following is a general guideline; always adhere to the specific prescription provided by a healthcare professional.

• Initial Dose: Often starts at 100 mg once daily.
• Titration: The dose may be increased weekly by 100 mg until a serum uric acid level of less than 6 mg/dL is achieved. The typical maintenance dose is 200-300 mg daily for mild gout.
• Severe Gout: Doses of 400-600 mg per day may be required, divided into 2-3 doses (for doses exceeding 300 mg).
• Maximum Dose: 800 mg per day.
• Administration: Tablets should be taken orally with a full glass of water. To minimize the potential for gastric upset, it is advisable to take Zyloprim after a meal.
• Fluid Intake: Patients are strongly encouraged to maintain adequate hydration (2-3 liters of fluid per day) to help excrete uric acid and reduce the risk of kidney stone formation.
• Renal Impairment: Dosage must be adjusted for patients with impaired kidney function. A lower initial dose and slower titration are necessary.

Precautions

Before and during treatment with Zyloprim, the following precautions should be observed:

• Renal Function: Baseline assessment of kidney function is mandatory. Renal function should be monitored periodically during therapy, as dosage adjustments are critical.
• Hepatic Function: Liver function tests should be performed at baseline and periodically thereafter, as allopurinol has been associated with hepatic toxicity.
• CBC Monitoring: A complete blood count should be obtained periodically due to the rare but serious risk of bone marrow suppression.
• Initial Gout Flare: Patients should be advised that starting allopurinol may precipitate an acute gout attack. Prophylactic NSAIDs or colchicine are often co-prescribed for the first few months of therapy to prevent this.
• Hypersensitivity: Patients must be informed about the signs of severe hypersensitivity reactions (see Side Effects) and instructed to discontinue the drug and seek immediate medical attention if they occur.
• Pregnancy and Lactation: Use during pregnancy only if clearly needed. Allopurinol crosses the placenta and is excreted in breast milk. A risk-benefit analysis with a physician is essential.

Contraindications

Zyloprim is contraindicated in patients with:

• A history of a severe hypersensitivity reaction to allopurinol or any component of the formulation.
• Patients who are currently experiencing an acute gout attack (initiation of therapy is not recommended during an acute episode).

Possible side effect

Like all medications, Zyloprim can cause side effects, ranging from common to rare but serious.

Common:

• Skin rash (may be a sign of a more serious reaction)
• Nausea, vomiting, or diarrhea
• Drowsiness or dizziness
• Headache

Less Common but Serious (require immediate medical attention):

• Severe Skin Reactions: Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS). Signs include skin rash, blistering, peeling, fever, and swelling.
• Hepatotoxicity: Symptoms like yellowing of the skin or eyes (jaundice), dark urine, severe nausea, and abdominal pain.
• Bone Marrow Suppression: Signs of infection (fever, chills), unusual bleeding or bruising, and extreme tiredness (symptoms of anemia).
• Eosinophilia: High levels of eosinophils, often part of a hypersensitivity syndrome.
• Acute Kidney Injury: Changes in urine output, swelling.

Drug interaction

Zyloprim can interact with several other medications, potentially altering their effects or increasing the risk of side effects. Key interactions include:

• Azathioprine & Mercaptopurine: Allopurinol potently inhibits the metabolism of these drugs, drastically increasing their toxicity (myelosuppression). Concomitant use requires a substantial reduction (by about 65-75%) of the azathioprine or mercaptopurine dose.
• Warfarin: Allopurinol may potentiate the anticoagulant effect of warfarin, increasing the risk of bleeding. Increased monitoring of INR is crucial.
• ACE Inhibitors (e.g., lisinopril, enalapril): Concomitant use may increase the risk of hypersensitivity reactions, including Stevens-Johnson syndrome.
• Diuretics (especially Thiazides): May increase the risk of allopurinol hypersensitivity reactions and can also reduce the excretion of allopurinol’s active metabolites.
• Ampicillin/Amoxicillin: Increased incidence of skin rash when used concurrently with allopurinol.
• Theophylline: Allopurinol may increase serum theophylline levels, necessitating monitoring.

Always provide your doctor and pharmacist with a complete list of all medications you are taking, including prescription, over-the-counter, and herbal products.

Missed dose

• If you miss a dose of Zyloprim, take it as soon as you remember.
• However, if it is almost time for your next scheduled dose, skip the missed dose and resume your usual dosing schedule.
• Do not take a double dose to make up for a missed one, as this increases the risk of side effects.

Overdose

Symptoms of overdose may include severe nausea, vomiting, diarrhea, and dizziness. In cases of significant overdose, more severe effects like acute kidney injury and bone marrow suppression could occur.

• Action: In case of suspected overdose, contact a poison control center or emergency room immediately.
• Treatment is primarily supportive and may include gastric lavage, hydration, and monitoring of hematological and renal parameters. Hemodialysis may be effective in removing allopurinol and its metabolites.

Storage

• Store Zyloprim tablets at room temperature, between 68°F and 77°F (20°C and 25°C).
• Keep the container tightly closed and protect from light and moisture.
• Keep all medications out of the reach of children and pets.
• Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed.

Disclaimer

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or medication. Never disregard professional medical advice or delay in seeking it because of something you have read here. The information provided may not cover all possible uses, directions, precautions, drug interactions, or adverse effects.

Reviews

• “After suffering from debilitating gout attacks for years, Zyloprim has given me my life back. The first few months required patience and management of a couple of flares, but I haven’t had a significant attack in over two years now. It’s a long-term commitment, but worth it.” - James L., 58
• “As an oncologist, I prescribe allopurinol routinely for tumor lysis syndrome prophylaxis. It is an effective and predictable drug for managing uric acid levels in this critical patient population, helping us avoid renal complications during aggressive chemotherapy.” - Dr. Eleanor R.
• “The initial skin rash I developed was concerning, and my doctor had me stop immediately. It resolved quickly. It’s crucial to be aware of your body’s reactions when starting this medication.” - Michael T., 45
• “Managing my chronic gout with Zyloprim has been straightforward. One pill a day, regular blood tests, and plenty of water. My uric acid levels are now consistently in the target range, and the constant joint pain is gone.” - Susan K., 62