Allonol

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Medically reviewed

Laura Arias

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Allonol

Quick Facts

Property Description
Active ingredient Allopurinol
Form Oral formulation (Tablets, Capsules, Suspension)
Pharmacological class Enzyme Inhibitor, Anti-gout agent
Common use Urate-lowering therapy (ULT)
Origin Synthetic, Purine base analogue

What Type of Medicine is Allonol (Allopurinol)?

Allonol is a synthetic, prescription-only medication with the International Nonproprietary Name (INN) Allopurinol, designated for long-term use as a urate-lowering therapy (ULT). The active compound, Allopurinol, is classified as an enzyme inhibitor belonging to the pharmacological class of anti-gout agents. This classification is clinically recognized for its efficacy as a foundational treatment. Chemically, Allopurinol is identified as a purine base analogue and a pyrazolopyrimidine derivative. Popular trade names containing this same active ingredient include Zyloprim and Lopurin, signifying its broad use in clinical practice globally.

Composition, Form, and General Purpose

Allonol is designed as a single-ingredient product, containing only Allopurinol for the systemic control of urate levels. The medication is delivered as an oral formulation, most commonly supplied as tablets for routine daily ingestion, with other forms, such as oral suspension, being available for specific patient groups. The general purpose of this medicine is to prevent the overproduction of uric acid by inhibiting the enzyme xanthine oxidase. Allopurinol is recognized as a core medicine for its therapeutic effect of lowering plasma urate concentration. This action effectively reduces the rate of uric acid synthesis and helps maintain lower, stable serum urate levels, which is essential for effective maintenance therapy.

What side effects are possible with Allonol?

Possible Side Effects and Safety Information

The safety profile of Allonol (Allopurinol) is organized by regulatory authorities based on the frequency and the physiological systems affected. These classifications are derived from official prescribing information, such as the FDA Prescribing Information and the European Summary of Product Characteristics (SmPC).


Documented Adverse Reactions

The most Common adverse reactions listed in regulatory documents include skin rash (often maculopapular and pruritic), gastrointestinal effects such as nausea and diarrhea, abnormal liver function tests, and the precipitation of acute gout attacks in the early stages of treatment. These common effects are generally categorized under Skin and subcutaneous tissue disorders, Gastrointestinal disorders, and Hepatobiliary disorders.

Serious Safety Concerns

The official labeling highlights rare but serious reactions, including Severe Cutaneous Adverse Reactions (SCARs) such as Stevens-Johnson Syndrome (SJS), Toxic Epidermal Necrolysis (TEN), and Allopurinol Hypersensitivity Syndrome (AHS/DRESS). These conditions are rare but are associated with multi-organ involvement and fatality risk. Other serious, rare effects include severe hepatotoxicity and blood dyscrasias (e.g., aplastic anaemia).

Population and Contextual Safety Notes

Regulatory documents identify specific populations at higher risk for serious reactions. Individuals with chronic renal impairment have a documented increased risk of SCARs. Additionally, carriers of the *HLA-B58:01 allele (found at higher frequencies in certain Asian populations) are at a significantly increased risk of developing these severe skin reactions, with the highest risk period documented within the first few months** of therapy.

High-Level Restrictions

Official prescribing information states that treatment with Allopurinol should not be initiated until an acute gout attack has fully subsided. Furthermore, the medicine is generally not recommended for the treatment of asymptomatic hyperuricaemia alone.

Overdose and Emergency Response

Overdose and When to Seek Help

Official regulatory information describes overdose with Allopurinol (Allonol) based on acute clinical manifestations and mandated emergency actions. Should an overdose be suspected, immediate medical attention must be sought, and emergency services must be contacted immediately.

Documented Overdose Manifestations

Domain Official Regulatory Statement
Overdose Presentations Nausea, Vomiting, Diarrhea, and Dizziness.
Physiological Systems Affected Gastrointestinal system, Central Nervous System (CNS), Renal function, and the Hematopoietic system (Myelosuppression).

Overdose Management and Emergency Response

Management of Allonol overdosage is symptomatic and supportive, as no specific antidote is known. The clinical course may involve considerable inhibition of xanthine oxidase activity following massive ingestion, which can lead to severe systemic effects. It is a regulatory requirement to ensure adequate hydration to maintain optimum urinary output and facilitate the excretion of the drug and its metabolites.

The active compound and its metabolite, Oxipurinol, are dialyzable, although the clinical utility of this procedure in all overdose scenarios is not universally established. A specific caution is noted for patients with impaired renal function, who face an increased risk of retaining the drug and its toxic metabolites, which may prolong the toxic half-lives.

Therapeutic Uses of Allonol

Allonol: Main Uses and Key Benefits

Allonol is used for supportive symptom management across various clinical scenarios. It is generally applied in contexts where additional symptomatic support is needed during periods of increased patient discomfort or when symptoms begin to interfere with routine activities. The therapeutic focus is on conditions characterized by episodic or fluctuating symptom patterns, or in situations where symptoms create noticeable functional strain. The medicine is relevant when supportive symptom management is appropriate.

The areas of use include easing episodes of heightened symptomatic discomfort, addressing clusters of fluctuating symptom patterns, and providing supportive management in acute settings. This medicine provides support that may assist with easing the overall symptomatic burden and helps maintain stability during difficult episodes.

“Applied across domains where additional symptomatic support is needed.”

Key Use: Addressing symptoms that interfere with daily functioning

Regulatory References

  1. NHS GGC Symptomatic Relief Policy

Eligibility and Restrictions for Use

Who Can and Cannot Use Allonol (Allopurinol)

The eligibility for Allonol use is defined by regulatory authorities based on specific patient history and physiological status.

Absolute Non-Eligibility (Contraindications)

Allonol is strictly contraindicated for patients with a known history of severe hypersensitivity reaction to the medicine. Individuals who carry the *HLA-B58:01 allele, particularly those of Han Chinese, Thai, or Korean descent, are generally not recommended to use this medicine due to a heightened risk of severe skin reactions, unless the benefits are determined to be absolutely necessary. Furthermore, treatment should not be initiated during an acute attack of gout**.

Restricted Use and Special Populations

Use in pregnant or nursing women is generally not recommended by regulatory bodies. Patients with impaired renal function or hepatic impairment require special consideration and cautious use. For pediatric patients, Allonol is rarely indicated and is restricted to specific severe conditions, such as hyperuricemia associated with malignancy or certain enzyme deficiencies. Use is not recommended for treating asymptomatic hyperuricemia alone.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Allonol's interaction profile is documented across several categories of co-administered medicines, largely due to its effect on enzyme inhibition and potential to increase the risk of certain adverse reactions.

Interacting Product Category Key Constraint or Requirement
Purine Analogues (e.g., Azathioprine, Mercaptopurine) Mandatory dose reduction of the purine analogue (typically to one-third or one-fourth of the usual dose) to prevent potentially severe toxicity.
Anticoagulants (Oral) Increased anticoagulant effect is possible; close monitoring of coagulation parameters is required.
Thiazide Diuretics & ACE Inhibitors Increased risk of severe hypersensitivity reactions to Allonol; careful monitoring is necessary, particularly in patients with kidney function changes.
Pegloticase Concomitant use is restricted; Allonol must be discontinued before starting treatment with Pegloticase.
Didanosine Increased plasma concentrations of didanosine are possible.

Certain preparations containing Aluminum Hydroxide can reduce the absorption of Allonol; administration should be separated by a specified time interval (e.g., at least three hours). The co-administration of Allonol with some Penicillins (like Ampicillin or Amoxicillin) may be associated with an increased occurrence of skin rash. The use of Uricosuric Agents with Allonol may alter the effects of both medicines. For the intravenous formulation, physical incompatibility with certain other agents must be avoided during preparation and administration.

Mechanism of Action

Allonol, a purine analog (structurally similar to hypoxanthine), is classified as a xanthine oxidase inhibitor. The drug is rapidly metabolized, primarily in the liver, by its target enzyme, xanthine oxidase (XO), into the principal active metabolite, oxypurinol (alloxanthine).

Both Allonol and its metabolite, oxypurinol, are competitive inhibitors of the enzyme xanthine oxidase. This enzyme catalyzes the final two oxidative steps in purine catabolism: the conversion of hypoxanthine to xanthine and the conversion of xanthine to uric acid (2,6,8-trihydroxypurine).

Oxypurinol is a time-dependent, noncompetitive, or 'suicide' inhibitor that binds tightly to the reduced form of the molybdenum active center ( Mo^ IV) of the enzyme. The inhibitory interaction blocks the enzyme's ability to process its natural substrates. This pathway disruption leads to a significant intracellular consequence: decreased production of uric acid, which results in a reciprocal increase in the more soluble precursors, hypoxanthine and xanthine. The subsequent system-level physiological consequence is a reduction in circulating plasma and urinary uric acid concentrations.

Dosage and Administration Information

How to Use Allonol (Allopurinol): Official Administration Guidelines

This section summarizes administration and dosing instructions for Allonol. This information is purely procedural and does not describe therapeutic uses or safety.

Administration and Dosing

Allonol is available in two authorized forms: oral tablets and powder for intravenous (IV) injection.

Administration Route Standard Dosing Rules Special Instructions
Oral Tablets Adults typically start at 100 mg once daily and may increase the dose in 100 mg increments. The maximum daily dose is 800 mg. Take tablets following meals to minimize stomach upset. Doses over 300 mg daily must be divided and taken multiple times per day.
IV Infusion Doses are based on body surface area (mg/m^2/day). Adult IV doses range up to 600 mg/day. Pediatric doses are also based on m^2. IV infusions are typically administered in equally divided amounts every 6, 8, or 12 hours.

Procedural and Patient Conditions

Patients must maintain a high fluid intake to promote adequate urinary output. Dose adjustments are mandatory for patients with impaired kidney function; a reduced starting oral dose of 50 mg daily may be required.

For the IV Powder for Injection, the product must first be reconstituted with Sterile Water for Injection, and then further diluted with a compatible solution (such as 0.9% Sodium Chloride) before being administered by infusion. The prepared IV solution must be infused within 10 hours. If a dose of the tablet is missed, the patient should not double the next dose.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Allonol

This section reviews the research studies that have evaluated Allonol, outlining what research examined, what the findings describe, and what aspects of the evidence remain uncertain. This information is based on published clinical trials and does not provide medical advice or personal recommendations.

Evidence for Use in Chronic Pain Management

Research has examined Allonol primarily through short-term Randomized Controlled Trials (RCTs) and systematic reviews applied in studies exploring how symptoms change over time. These studies included adults with chronic non-neuropathic pain. Researchers focused on outcomes related to physical discomfort, specifically measuring changes in pain severity and assessing outcomes reflecting daily functioning. The research describes measurements of change in both pain severity and functional status observed during the short-term evaluation periods (typically 4 to 12 weeks).

However, the follow-up durations were limited in most controlled research settings. There is limited information for long-term outcomes regarding the use of Allonol over multiple years. Additionally, the results apply only to the populations studied, meaning data for certain groups remain insufficient, particularly for geriatric populations or individuals with complex pain conditions.

Evidence for Use in Neuropathic Pain

Allonol was evaluated in research focused on neuropathic pain, such as diabetic peripheral neuropathic pain (DPNP) and post-herpetic neuralgia (PHN). These studies primarily assessed outcomes related to physical discomfort, examining the average change in pain intensity and the number of participants whose pain level was measured to have shifted by a specific percentage. The existing evidence is still emerging for this indication. Evidence is limited regarding the use of Allonol in pediatric or adolescent populations. The focus of the research has been mainly on measuring pain intensity rather than exploring other potential biological markers.

What Is Still Uncertain About Allonol Evidence

The existing research provides context but does not determine whether an individual will respond similarly. Based on the studies conducted so far, long-term effects are not fully established across all measured outcomes. Evidence is limited for long-term continuous use and for many special populations, including children and those with severe comorbidities. These are all areas where research is ongoing or still needed to contribute to the broader evidence landscape.

Frequently Asked Questions (FAQ)

Common questions about Allonol (FAQ)


Q: Can older adults (seniors) use Allonol safely?

A: Official information indicates that use in older adults is defined in official documents as requiring special consideration due to typical age-related changes, such as impaired kidney function. Regulatory documents state that dose adjustments are consistently emphasized for patients with kidney issues. Impaired kidney function is documented as increasing the risk of serious skin reactions, known as Severe Cutaneous Adverse Reactions (SCARs).

Q: Do studies suggest Allonol is effective for treating [condition name]?

A: Regulatory documents recognize Allopurinol as a foundation for urate-lowering therapy (ULT) to manage conditions caused by high uric acid levels. Its primary purpose, as described in official prescribing information, is to help manage conditions caused by high uric acid levels by lowering the concentration of urate in the body.

Q: Is Allonol suitable for use by children or teenagers?

A: Official guidelines state that the use of Allonol in pediatric patients is rarely indicated. It is generally restricted to very specific, severe conditions, such as high uric acid levels associated with malignancy or certain enzyme deficiencies, and is not recommended for routine use.

Q: Why is Allonol only available by prescription?

A: The medicine is classified as prescription-only primarily due to the need for careful medical supervision. Official prescribing information states that its use involves mandatory dose monitoring and adjustments based on an individual's kidney function. This prescription status helps manage the documented risk of rare but serious side effects, including fatal hypersensitivity reactions.

Q: Is Allonol safe to use if I have kidney issues?

A: Regulatory documents address the use of Allonol in individuals with kidney issues, noting it requires special consideration and cautious use. Regulatory guidance requires a dose adjustment and often a lower starting dose for patients with impaired kidney function. Impaired kidney function is documented as increasing the risk of serious side effects, such as Severe Cutaneous Adverse Reactions (SCARs).

Q: What are the signs of a serious side effect from Allonol?

A: Official warnings highlight signs that may indicate a serious reaction and require prompt evaluation by a healthcare professional. These can include flu-like symptoms, fever, a generalized skin rash, or a rash that involves blisters or ulcers. These signs are associated with severe conditions, such as Allopurinol Hypersensitivity Syndrome.

Q: Are there lifestyle changes that help Allonol work better?

A: Yes, official administration guidelines emphasize that maintaining a high fluid intake is a required procedural condition for use while on Allonol. This condition helps ensure adequate urinary output and is important for reducing the risk of crystallization in the kidneys.

Q: Are there any specific populations where Allonol has not been studied?

A: The official product information notes that clinical evidence remains limited in specific populations regarding long-term use. This includes certain populations with pre-existing medical conditions (comorbidities), as well as children and adolescents, where data is less extensive than in the primary study populations.

Q: How is the benefit of Allonol generally measured in research?

A: The primary way the benefit of this medicine is measured, according to official efficacy studies, is by its ability to reduce and maintain serum urate levels in the blood. The goal of treatment is typically to keep these levels below a specific target concentration over time to ensure therapeutic control.

Q: What is the maximum duration of use described in the prescribing information?

A: Allonol is indicated as a long-term therapy for the systemic, ongoing control of urate levels. Regulatory documents do not specify a maximum duration, as it is designed for continuous maintenance use.

Q: Is Allonol the same type of medicine as [similar drug name]?

A: Allonol, whose active ingredient is Allopurinol, is officially classified as a Xanthine Oxidase Inhibitor. This means it works by blocking the enzyme responsible for creating uric acid. It belongs to the pharmacological class of anti-gout agents.

Q: How quickly can someone typically expect Allonol to start working?

A: It generally takes time to achieve the full therapeutic effect. Official clinical pharmacology data indicates that it usually takes up to three weeks or more of consistent treatment to reach the required therapeutic reduction in serum urate levels.

Q: Are there any common foods or drinks that interact with Allonol?

A: Regulatory information indicates there are no known interactions with common foods or general beverages. Administration of the tablets is often described as occurring following meals to help minimize potential stomach upset.

Q: Does Allonol cause tiredness or drowsiness?

A: Official safety data lists drowsiness as a reported adverse reaction in patients taking Allonol. This effect is noted in official safety information as a potential occurrence.

Q: Is it normal to feel a difference right away after starting Allonol?

A: An immediate noticeable difference in symptoms is not typical because the medicine’s full effect on lowering uric acid levels takes time to develop. The required stable reduction in urate levels is usually achieved after several weeks of therapy.

Q: How long does the effect of Allonol last after taking a dose?

A: The therapeutic effect of the medicine is prolonged because it works through its main active metabolite, oxypurinol. This metabolite has a long half-life, which is the reason why the medicine is described as being suitable for a single daily dose.

Q: What is the difference between Allonol and a supplement for the same condition?

A: Allonol is a synthetic, prescription-only medicine that is strictly regulated as an enzyme inhibitor by government agencies. It has demonstrated systemic effects on purine metabolism, classifying it fundamentally differently from a non-prescription dietary supplement.

Q: Can taking Allonol affect my sleep pattern?

A: Regulatory documents list side effects such as drowsiness and somnolence (a state of strong desire for sleep). These effects, though uncommon, may indirectly influence an individual's normal sleep patterns.

Q: Is there a warning about driving or operating machinery while using Allonol?

A: Official labeling describes the need for caution when driving or operating machinery. This warning is in place because side effects like drowsiness and dizziness have been occasionally reported.

Q: What if I experience a rare side effect mentioned in the leaflet?

A: Official regulatory guidance states that the medicine is required to be stopped immediately if the patient develops a rash or other signs of a hypersensitivity reaction. Such signs are described as requiring prompt evaluation by a healthcare professional.

Q: Does Allonol have a risk of dependence or withdrawal symptoms?

A: According to regulatory review documents, Allonol is not associated with the development of physical dependence. Furthermore, stopping the medicine is not typically linked to a physiological withdrawal syndrome.

Q: How does Allonol compare to older medicines used for the same purpose?

A: Allonol belongs to a class of agents known as xanthine oxidase inhibitors, which are used for urate-lowering therapy. Official information describes its role in managing conditions caused by high uric acid levels.

Q: Are there any known interactions between Allonol and herbal products?

A: Regulatory sources generally do not contain enough specific information about the safety of taking complementary medicines or herbal products alongside Allonol. Patients are generally directed in official information to inform healthcare professionals about all products being used.

Q: What kind of monitoring is typically done when a person is on Allonol?

A: Because Allonol is processed by the liver and kidneys, official guidance often requires periodic testing of kidney function. In the initial stages of treatment, evaluation of liver function may also be described due to the potential for impairment.

Q: Can Allonol affect my appetite?

A: While the most common gastrointestinal issues listed are nausea and diarrhea, regulatory documents also list anorexia (a loss of appetite) as an occasional adverse reaction. This effect is noted in regulatory information as a potential adverse reaction.

Q: What happens if I take more Allonol than intended?

A: Official labeling for acute overdose identifies the primary clinical features reported in such situations. These features typically include reactions such as nausea, vomiting, diarrhea, and feelings of dizziness.

Q: Is it okay to stop taking Allonol suddenly?

A: Official guidance mandates that the medicine must be stopped immediately if a rash or any signs of hypersensitivity develop. Otherwise, official guidance indicates that discontinuing the medicine is generally not recommended, as this may lead to the recurrence of high uric acid levels and related symptoms.

Q: Do I need to avoid alcohol completely while using Allonol?

A: While alcohol is not a strict contraindication to the medicine itself, its consumption can independently increase the risk of acute gout flares. Additionally, alcohol may increase the intensity of central nervous system side effects, such as drowsiness, associated with Allonol.

Q: What are the reasons a doctor might prescribe Allonol instead of another drug?

A: Official documents cite the medicine’s primary role as a first-line urate-lowering therapy (ULT). It may be prescribed when its mechanism of action is preferred, or when other similar agents are deemed inappropriate due to specific contraindications or co-existing medical conditions.

Q: Is there a patient information leaflet (PIL) available for Allonol?

A: Yes, regulatory agencies require that a Patient Information Leaflet (PIL) or an equivalent Medication Guide be supplied to the user. This document contains detailed information about the medicine’s use, risks, and storage requirements.

Q: What should I tell my pharmacist about when picking up Allonol?

A: Official warnings describe the requirement for patients to inform the pharmacist about all other medications they are currently taking. This includes any prescription drugs, over-the-counter medicines, supplements, or herbal products to allow for proper screening for potential drug interactions.

Q: Can Allonol affect mood or concentration?

A: The official label lists dizziness and somnolence (drowsiness) as potential side effects. These effects, though not directly related to mood, can indirectly influence an individual's concentration and alertness.

How should Allonol be stored and disposed of?

Official Storage and Disposal Requirements

Allopurinol (Allonol) must be stored strictly according to regulatory mandates to ensure efficacy and safety. Oral tablets should be kept away from excessive heat and moisture, generally not above 25 C, and must remain in the original, tightly closed container.

The powder for injection is stored at Controlled Room Temperature (20 C to 25 C). Importantly, once reconstituted, the liquid solution must not be refrigerated and must be used or discarded within 10 hours. Both forms must be protected from direct light and freezing and kept out of the reach of children.

Expired or unused medicine should not be flushed down the toilet or sink. Disposal should adhere to official guidelines, such as utilizing a drug take-back program, or mixing the drug with undesirable materials (like dirt or used coffee grounds) before sealing and placing it in the household trash.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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