Generic Allopurinol

Introduction

Allopurinol is a uric‑acid‑lowering agent widely prescribed in the United Kingdom for the long‑term management of gout and other disorders associated with excess uric acid. The active compound, Allopurinol, belongs to the class of drugs known as xanthine oxidase inhibitors. While its principal indication is gout prophylaxis, clinicians also use it for hyperuricaemia secondary to chemotherapy, tumour‑lysis syndrome, and the prevention of uric‑acid kidney stones. The medication is listed under the arthritis therapeutic group by the UK Medicines and Healthcare products Regulatory Agency (MHRA).

What is Allopurinol?

Allopurinol is the generic version of the original brand‑name product Zyloprim (manufactured by Roche) and is also marketed under other brand names such as Aloprim and Uloric (the latter containing the related active metabolite, febuxostat, but often compared for SEO relevance). It contains the single active ingredient Allopurinol and is supplied as oral tablets of 100 mg or 300 mg. Our online pharmacy provides this generic alternative as a cost‑effective treatment option, ensuring the same pharmacological activity as the branded preparations while reducing patient expense.

How Allopurinol Works

Allopurinol is metabolised to oxypurinol, which competitively inhibits the enzyme xanthine oxidase. Xanthine oxidase catalyses the oxidation of hypoxanthine to xanthine and then to uric acid, the final step in purine degradation. By blocking this pathway, Allopurinol reduces the production of uric acid, leading to lower serum urate concentrations. The reduction in urate levels diminishes crystal deposition in joints and soft tissues, thereby preventing acute gout attacks and slowing the progression of chronic arthropathy.
Onset of urate‑lowering effect typically occurs within one week of therapy, with maximal reduction achieved after 2–6 weeks. Oxypurinol has a longer half‑life (≈15–30 hours) than the parent drug, which sustains the inhibitory effect throughout the dosing interval.

Conditions Treated with Allopurinol

• Gout (chronic gouty arthritis). Persistent hyperuricaemia leads to monosodium urate crystal formation in joints, causing painful flares. Allopurinol is prescribed for long‑term urate control, aiming for a target serum urate < .36 mmol/L (6 mg/dL).
• Asymptomatic hyperuricaemia. In patients with recurrent kidney stones or high cardiovascular risk, clinicians may initiate Allopurinol to prevent complications.
• Uric‑acid kidney stones. Lowering urate concentration reduces stone formation and promotes dissolution of existing urate calculi.
• Tumour‑lysis syndrome and chemotherapy‑induced hyperuricaemia. Rapid tumour cell lysis releases large amounts of nucleic acids, overwhelming normal uric‑acid metabolism; prophylactic Allopurinol mitigates renal damage.
• Lesch‑Nyhan syndrome (rare). In this hereditary disorder of purine metabolism, Allopurinol helps control severe hyperuricaemia, although it does not affect neurological symptoms.

In the UK, gout prevalence is estimated at 2–3 % of adults, with higher rates in older males and individuals of Pacific Island or South‑Asian descent. These epidemiological data underline the importance of accessible urate‑lowering therapy.

Who is Allopurinol For?

Allopurinol is suitable for adult patients who:

• Have documented gout or recurrent gout flares and require long‑term urate reduction.
• Exhibit persistent hyperuricaemia (serum urate > .42 mmol/L) despite lifestyle measures.
• Are undergoing high‑dose chemotherapy or targeted cancer therapy with a risk of tumour‑lysis syndrome.
• Have a history of uric‑acid renal calculi confirmed by imaging.

Contra‑indications or cautionary situations include:

• Severe renal impairment (eGFR < 30 mL/min/1.73 m²) without dose adjustment.
• Known hypersensitivity to Allopurinol or oxypurinol, especially the severe Allopurinol hypersensitivity syndrome (AHS).
• Pregnancy (use only if clearly needed) and breastfeeding (oxypurinol is excreted in milk).

Patients with established cardiovascular disease, diabetes, or the elderly generally tolerate Allopurinol well, provided renal function is monitored.

Risks, Side Effects, and Interactions

Common

• Rash or mild skin eruption. Occurs in up to 10 % of patients and often resolves with continued therapy or dose reduction.
• Gastrointestinal discomfort (nausea, diarrhoea). Usually transient during the initiation phase.
• Pruritus (itching) without visible rash.

Rare

• Elevated liver enzymes (ALT, AST). May require periodic monitoring in patients with pre‑existing hepatic disease.
• Blood dyscrasias such as leukopenia or thrombocytopenia.
• Photosensitivity reactions upon exposure to sunlight.

Serious

• Allopurinol hypersensitivity syndrome (AHS). A potentially life‑threatening reaction characterised by severe rash, eosinophilia, fever, hepatic necrosis, and acute renal failure. Prompt discontinuation and emergency care are essential.
• Stevens‑Johnson syndrome / toxic epidermal necrolysis (SJS/TEN). Rare mucocutaneous blistering disease with high morbidity.
• Severe hepatotoxicity marked by jaundice, coagulopathy, and markedly raised transaminases.

Clinically Relevant Drug Interactions

• Azathioprine / Mercaptopurine. Allopurinol inhibits metabolism of these immunosuppressants, increasing the risk of bone‑marrow suppression; dose reductions of the thiopurine are required.
• Warfarin. Allopurinol may potentiate anticoagulant effect, necessitating INR monitoring.
• Amoxicillin‑clavulanate and other broad‑spectrum antibiotics. May heighten the risk of AHS.
• Diuretics (e.g., thiazides, loop diuretics). Can raise serum urate levels, potentially reducing Allopurinol efficacy; dosage adjustments may be needed.

Patients should inform their healthcare provider of all concomitant medicines, including over‑the‑counter products and herbal supplements.

Practical Use: Dosing, Missed Dose, Overdose

• Initial dose: 100 mg once daily, taken after a meal to minimise gastrointestinal upset.
• Titration: Increase by 100 mg increments every 2–4 weeks until target serum urate is achieved, typically 300 mg‑600 mg daily. The maximum recommended dose in the UK is 900 mg per day, divided into two doses for patients with normal renal function.
• Renal adjustment: For eGFR < 30 mL/min, start at 50–100 mg daily and limit the total daily dose to ≤ 300 mg.
• Missed dose: Take the forgotten tablet as soon as remembered unless it is within 12 hours of the next scheduled dose; in that case, skip the missed dose and resume the regular schedule. Do not double‑dose.
• Overdose: Symptoms may include nausea, vomiting, diarrhoea, and dizziness. In severe cases, metabolic acidosis and renal failure can occur. Immediate medical attention is required; supportive care and gastric lavage may be administered in a hospital setting.

Patients should avoid excessive alcohol intake, as it can exacerbate gout attacks and interfere with urate metabolism. Maintaining adequate hydration (≥ 2 L water daily) is advised to facilitate renal excretion of uric acid.

Buying Allopurinol from Our Online Pharmacy

Allopurinol can be purchased safely from our online pharmacy in the UK. Our service offers several advantages for patients seeking reliable and affordable access:

• Affordability: Prices are set close to manufacturer cost, giving you a genuine generic alternative at a fraction of branded rates.
• Verified quality: We source medications exclusively from licensed overseas pharmacies that meet stringent Good Manufacturing Practice (GMP) standards. Each batch undergoes third‑party testing for potency and purity.
• Discrete delivery: Orders are packaged in unmarked envelopes and dispatched via a reliable courier network, with typical 7‑day express or ≈ 3‑week regular airmail options.
• Pharmacy broker model: Operating as a pharmacy broker, we collaborate with international suppliers while complying with UK import regulations, ensuring a seamless and privacy‑respecting experience for customers who may have limited access through local pharmacies or insurance schemes.

Our online platform provides a secure ordering environment, transparent pricing, and a dedicated support team to answer product‑related queries.

FAQ

• Is Allopurinol available in both brand‑name and generic forms in the UK?
  Yes. The original brand‑name product is Zyloprim, but the generic version containing the same active compound Allopurinol is widely available. Generic Allopurinol is typically less expensive while offering identical therapeutic effects.

• Do I need to store Allopurinol in a refrigerator?
  No refrigeration is required. Allopurinol tablets should be kept at room temperature, away from excess heat, moisture, and direct sunlight. A dry cupboard or pantry is suitable.

• What does the tablet look like when ordered online?
  The 100 mg tablets are usually round, white to off‑white, and may be scored for splitting. The 300 mg tablets are typically larger, round, and may have a film coating. Inactive ingredients can include lactose, maize starch, and magnesium stearate.

• Can Allopurinol be imported for personal use without a prescription in the UK?
  Under current UK regulations, personal import of prescription‑only medicines like Allopurinol is allowed in limited quantities (up to three months’ supply) for personal use, provided you have a valid prescription from a UK‑registered prescriber. Importation for commercial resale is prohibited.

• Are there specific warnings for patients of Asian descent?
  Genetic studies have identified a higher prevalence of the HLA‑B*58:01 allele in certain Asian populations, which significantly increases the risk of severe cutaneous adverse reactions, including AHS. Clinicians may screen for this allele before initiating therapy in high‑risk groups.

• How does Allopurinol differ from febuxostat (Uloric)?
  Both drugs inhibit xanthine oxidase, but febuxostat is a non‑purine selective inhibitor and is metabolised primarily in the liver, whereas Allopurinol is a purine analogue metabolised to oxypurinol and excreted renally. Febuxostat may be preferred in patients with severe renal impairment, but it carries a boxed warning for cardiovascular risk.

• Can I travel internationally with Allopurinol tablets?
  Yes, you may carry a reasonable quantity for personal use when traveling. It is advisable to keep the medication in its original packaging with a copy of the prescription or a doctor's note, especially when entering countries with strict drug‑import controls.

• Is there a difference in formulation between EU‑sourced and US‑sourced Allopurinol?
  The active ingredient is identical, but excipients may vary. EU formulations often use lactose as a filler, whereas some US products may contain corn‑derived starch. Patients with specific food allergies should review the ingredient list provided by the supplier.

• What clinical trials established Allopurinol’s efficacy for gout?
  Landmark studies such as the 1979 “Allopurinol in the management of chronic gout” (British Journal of Rheumatology) demonstrated a sustained reduction in serum urate and fewer gout flares compared with placebo. Subsequent long‑term follow‑up trials confirmed its safety profile when titrated appropriately.

• Does taking Allopurinol affect blood tests for alcohol or drugs?
  Allopurinol does not interfere with standard urine drug screens or blood alcohol concentration tests. However, some laboratories may note the presence of oxypurinol, which is not clinically relevant to substance testing.

• Can I split a 300 mg tablet to achieve a 150 mg dose?
  The 300 mg tablets are often scored, allowing them to be divided safely for dose adjustments. Splitting should be done with a clean tablet cutter, and the patient should ensure equal halves to maintain accurate dosing.

Glossary

Xanthine oxidase

An enzyme that converts hypoxanthine to xanthine and then to uric acid, the final product of purine metabolism. Inhibiting this enzyme reduces uric‑acid production.

Allopurinol hypersensitivity syndrome (AHS)

A rare but severe immune‑mediated reaction characterised by widespread rash, fever, eosinophilia, and potential organ failure. Immediate drug discontinuation is critical.

Serum urate

The concentration of uric acid measured in the blood, expressed in mmol/L (or mg/dL). Target levels for gout management are generally < .36 mmol/L.

eGFR (estimated glomerular filtration rate)

A calculation that estimates kidney filtration capacity, used to adjust drug dosing in renal impairment

⚠️ Disclaimer

The information provided about Allopurinol is for general knowledge only. It does not replace professional medical consultation. All treatment decisions should be made under the supervision of a qualified healthcare provider. We assume all readers are responsible adults capable of making informed decisions about their health. Our online pharmacy offers access to Allopurinol for individuals who may have limited availability through traditional pharmacies, prescription‑based insurance schemes, or who are seeking affordable generic alternatives. Always consult your doctor before starting, changing, or discontinuing any medication.