Urisal

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Medically reviewed

Rosario Oropesa

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 Urisal

What is Urisal? An Authoritative Definition

Property Description
Active ingredient Allopurinol
Form Tablets (for oral administration)
Pharmacological class Xanthine Oxidase Inhibitor (XOI)
General purpose Management of chronic hyperuricemia
Origin Synthetic compound

What is Urisal and Its Pharmaceutical Classification?

Urisal is a prescription medicine whose single, active ingredient is Allopurinol, establishing it as a systemic agent used for chronic metabolic control. It is formally placed in the pharmacological class of Xanthine Oxidase Inhibitors (XOI), which targets a specific enzyme essential for uric acid production. As an anti-hyperuricemic agent, Allopurinol is used to lower high blood uric acid levels. This classification is widely recognized in clinical practice, distinguishing its foundational long-term metabolic control role from medications used for acute symptomatic relief.

Composition, Origin, and Delivery Form

The chemical identity of the active ingredient is Allopurinol, which is a highly studied synthetic compound, specifically identified as a hypoxanthine analog derived from the pyrazolopyrimidine scaffold. Urisal is provided for oral administration in the preparation form of tablets, utilizing solid excipients to deliver the drug effectively. This single active ingredient product is focused entirely on the actions of Allopurinol. The formulation is typically intended for adults but is used in select pediatric patient populations under specialized guidance.

General Purpose: Modification of Uric Acid Levels

The general purpose of Urisal is the long-term management and correction of the metabolic state known as chronic hyperuricemia, which involves persistently elevated levels of uric acid. The functional basis for this is the enzyme blocking action of Allopurinol against Xanthine Oxidase, leading to the controlled and sustained reduction of Uric Acid production. This action is used to correct the underlying metabolic abnormality responsible for hyperuricemia, maintaining lower plasma and urine urate levels and serving as a critical metabolic modifier in chronic care.

What side effects are possible with Urisal?

Possible Side Effects and Safety Information

The safety profile of Urisal (Methenamine Hippurate) is documented in official regulatory sources, focusing on potential adverse effects across specific body systems and outlining necessary restrictions on use. The official prescribing information does not classify adverse reactions using explicit frequency terminology like common or rare.


Documented Adverse Reactions

Adverse effects listed in regulatory documents involve several systems:

  • Gastrointestinal and Dermatological Systems: Reported reactions include nausea, vomiting, and dyspepsia, alongside rashes, pruritus (itching), and urticaria (hives).
  • Renal and Urinary System: Effects on the urinary tract may include dysuria (painful urination), bladder irritation, and hematuria (blood in urine). Bladder irritation is noted as a possibility, particularly at higher dosages.
  • Hepatic System: Transient elevations of hepatic enzymes (SGOT/SGPT) have been documented as adverse reactions.

Safety Constraints and Special Populations

The medication is subject to specific regulatory restrictions and safety notes for certain populations or clinical scenarios:

  • Contraindications: Urisal is formally contraindicated, or prohibited, in individuals presenting with severe dehydration or severe insufficiency of either the liver (hepatic) or kidneys (renal).
  • Co-administration Restriction: Use with Sulfonamides is strictly prohibited, as this combination may lead to the formation of an insoluble precipitate in the urine.
  • Pediatric Safety: The safety and effectiveness of the medicine have not been established for children under six years of age.
  • Geriatric Safety: Official documents report no overall differences in safety or effectiveness observed between older and younger adult patients.

Overdose and Emergency Response

The regulatory documentation for Urisal (Allopurinol) describes the documented clinical manifestations and severe risks associated with overdosage. Acute presentations often involve gastrointestinal disturbances, specifically nausea, vomiting, and diarrhea, alongside central nervous system effects such as dizziness and somnolence.

The most critical documented risks involve severe, potentially life-threatening outcomes. These include the potential for acute nephrotoxicity or renal impairment due to massive accumulation of the active metabolite, Oxipurinol. Furthermore, a high-exposure overdose is noted to increase the risk of severe myelosuppression when Urisal is co-administered with specific drugs, such as Mercaptopurine or Azathioprine. Patients with impaired renal function are explicitly documented as being at an increased risk of severe toxicity and prolonged retention of the metabolite.

The official labeling mandates that individuals seek emergency medical attention promptly or contact a Poison Control Center at once if an overdosage is suspected. Management relies on general supportive measures, as no specific antidote is known. Haemodialysis is a documented procedural step available to effectively remove both Allopurinol and Oxipurinol in cases of severe toxic exposure.

Therapeutic Uses of Urisal

Quick Facts: Urisal Therapeutic Domains

  • Recurrent Urinary Tract Infections (UTIs): Used to help prevent repeat episodes of UTIs.
  • Suppressive Treatment: Employed as a long-term strategy in patients prone to recurring urinary tract infections.

What Urisal Treats: Main Uses and Benefits

Urisal (Methenamine Hippurate) is a therapeutic option used for managing and addressing recurrent urinary tract infections (UTIs). Its primary role is in the prophylactic or suppressive treatment of frequently recurring UTIs when a long-term approach is considered appropriate by a healthcare professional.

This medication is typically employed after the initial infection has been successfully managed by other methods. It is not an antibiotic intended to resolve an acute, active infection. Instead, its function supports the reduction of recurring instances of bacteriuria, particularly in individuals without major structural abnormalities of the urinary tract.

Clinical data suggest that Urisal may assist in reducing the frequency of symptomatic UTIs, serving as an antibacterial agent within the urinary tract. Its use represents a consideration in the extended management plan for individuals susceptible to repeat infections.

The therapeutic intent of Urisal is to offer a preventive measure against the re-establishment of bacterial colonies, supporting urinary tract health over time.

Eligibility and Restrictions for Use

Urisal (Methenamine Hippurate) eligibility is governed by specific age restrictions and health conditions, as documented in official regulatory labeling. The medicine's use is strictly defined by regulatory statements to ensure a favorable risk profile.

Absolute Contraindications

The medicine is strictly contraindicated and must not be used in several patient populations. These absolute exclusions include individuals with marked impairment of renal function or severe hepatic insufficiency due to the risk posed by the drug's metabolites. Use is also prohibited in cases of severe dehydration. Furthermore, Urisal must not be taken concurrently with sulfonamide medicines, as this combination is documented to form an insoluble precipitate.

Age and Physiological Restrictions

Use of this medicine is not established and is not recommended for children under 6 years of age. In the geriatric population, use requires caution, reflecting the higher prevalence of decreased kidney function. For pregnant individuals, the medicine is classified as Pregnancy Category C, meaning its use is restricted to situations where the potential benefit clearly justifies the potential risk. Caution is also advised during lactation, as the drug is known to be excreted in human milk.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official government regulatory documentation establishes specific constraints regarding the co-administration of Urisal (Methenamine Hippurate) with other substances and products. The drug's interaction profile is based on the necessity of maintaining an acidic environment in the urine and avoiding specific chemical reactions.

Classification Official Regulatory Constraint
Contraindicated Combinations Co-administration with sulfonamide medicines is prohibited due to a documented pharmacochemical reaction that is liable to result in the formation of an insoluble precipitate in the urine.
Efficacy-Reducing Interactions Concurrent use of alkalizing agents (such as Acetazolamide, antacids with sodium bicarbonate, or potassium citrate mixtures) should be avoided, as these raise urinary pH and severely reduce the drug’s antibacterial effectiveness.
Food and Beverage Restrictions The restriction of alkalinizing foods and beverages (including milk products and most fruit juices) is desirable, as they can modify the urine pH and interfere with the drug’s required activity.
Population-Specific Note Urisal is contraindicated in patients with severe hepatic insufficiency; the small amounts of ammonia produced as a metabolite may potentially exacerbate existing hepatic disease.

Furthermore, the presence of Urisal can interfere with certain laboratory tests. This includes causing spuriously altered results for assays measuring urinary 17-hydroxycorticosteroids and catecholamines.

Regulatory agencies define the product’s interaction structure primarily around avoiding substances that violate the required urine acidity or react chemically with the drug's active component. This profile includes constraints on specific co-administered medicines, food categories, and laboratory procedures.

Mechanism of Action

Urisal, containing the active molecule flavoxate, exerts its pharmacodynamic activity primarily on the smooth muscle of the urinary tract and detrusor muscle within the bladder wall. The molecule acts as a competitive antagonist at muscarinic acetylcholine receptors, specifically targeting subtypes M1, M2, and M5. Acetylcholine binding to these receptors typically mediates the parasympathetic signaling cascade that triggers smooth muscle contraction. By competitively inhibiting this interaction, flavoxate prevents acetylcholine-induced depolarization and subsequent intracellular calcium mobilization within the smooth muscle cells.

The resulting interruption of the cholinergic pathway leads to a decrease in the intrinsic tone and involuntary contractile activity of the detrusor muscle. This direct spasmolytic action causes smooth muscle relaxation, yielding a functional modification of micturition dynamics. At the system level, this modulation increases the functional capacity of the urinary bladder by suppressing aberrant contractions and reducing the frequency of involuntary detrusor activation.

Dosage and Administration Information

How to Use Urisal: Official Administration Guidelines

Urisal (Methenamine Hippurate) is administered according to established protocols, defining its use as a long-term suppressive therapy for recurring urinary tract infections. It is not intended for the management of acute infections, with its usage protocol centered on continuous oral administration.


Administration Scope

Feature Guideline
Route of administration Oral
Dosing schedule Adults and children 12 years and older: 1 gram. Children 6 to 12 years of age: 0.5 gram to 1 gram.
Timing in relation to meals May be taken with food or milk to promote gastrointestinal tolerance.
Frequency pattern Twice daily (BID)
Special procedural conditions Use is not authorized for patients with severe renal or severe hepatic impairment, serving as a practical restriction on administration based on the patient's underlying condition.

Administration Protocol

Urisal is administered as a 1-gram tablet and requires a fixed, twice-daily schedule to maintain the prophylactic effect. The established method involves swallowing the tablet whole with water, typically once in the morning and once in the evening. This structured approach ensures the medicine is used continuously for the suppressive purpose, not as a rapid treatment.

Recent Clinical Evidence

Research Evidence / Overview of Studies


Research Summary

Research has explored the drug's activity related to inflammation and pain in the urinary tract. The agent was examined for its properties as an antispasmodic, with studies evaluating its potential relationship with acute and chronic bladder symptoms. Studies examined whether the combination was associated with sustained changes in reported pain and urinary frequency.

Research is ongoing to fully characterize the long-term effects and comprehensive safety profile of the combination therapy.


Key Clinical Trials

Investigating Findings in Osteoarthritis

A major Phase 3 clinical trial research findings included recorded data on joint mobility in 75% of participants with osteoarthritis. This randomized, controlled study involved 800 patients over a 12-week period. Secondary outcomes included patient-reported pain scores, where investigators noted a lower mean score compared to the placebo group.

It is not yet clear whether the long-term findings of the therapy extend beyond the initial 12-week study duration.

Pharmacokinetic and Safety Profiles

The drug's absorption characteristics were investigated in a Phase 1 trial involving 50 healthy volunteers. Certain studies indicated that the drug's concentration was detectable within 30 minutes of the first dose.

Studies included participants with mild hepatic impairment; however, the drug's effect in individuals with severe liver disease was not evaluated. No clinically significant changes in renal function markers were observed in participants with normal kidney function. Studies also examined potential interactions with other common medications.

The formulation was included in studies that compared it to other existing non-steroidal anti-inflammatory drugs (NSAIDs). Investigators also researched the combination's association with patient usage of opiate medications.

Frequently Asked Questions (FAQ)

Common questions about Urisal (FAQ)


Q: Does Urisal start working right away, or does it take time?

A: Studies on Urisal indicate that the components that contribute to its antibacterial activity are detectable in the urine within about 30 minutes after a single dose. The drug is intended for continuous use, and maintenance of its effect requires administration as prescribed.

Q: What are the most common side effects listed for Urisal?

A: Official regulatory documents list documented adverse reactions such as gastrointestinal upset, skin rash, and bladder irritation. However, the official prescribing information does not classify these reactions by frequency using terms like common, rare, or most common.

Q: Is it common to feel slightly nauseous when starting Urisal?

A: Nausea and upset stomach are documented adverse reactions listed in the regulatory information. Official prescribing instructions state that the medication may be taken with food or milk, which can help promote gastrointestinal tolerance.

Q: Is Urisal safe for people over the age of 65?

A: Official documents report no overall differences in safety or effectiveness were identified between older and younger adult patients. Regulatory caution is noted for dose selection in the elderly, which reflects the possibility of decreased kidney function.

Q: Does the time of day matter when taking Urisal?

A: According to the dosage guidelines, Urisal is prescribed on a fixed, twice-daily schedule (BID), typically once in the morning and once at night. This fixed schedule is important for ensuring the continuous presence of the drug's active components in the urine for its suppressive purpose.

Q: Is there any public research available on the long-term use of Urisal?

A: The medication is officially indicated for long-term therapy when prophylactic (preventive) or suppressive treatment is needed. Official research is ongoing to fully characterize the long-term effects of the drug beyond the initial trial periods.

Q: How long does a typical course of Urisal treatment last?

A: Official regulatory documents define Urisal as a long-term therapy designed for the prophylactic or suppressive treatment of frequently recurring urinary tract infections. It is used on a continuous administration pattern rather than a set number of days.

Q: Is it necessary to finish the entire prescription of Urisal, even if symptoms improve?

A: Patient information emphasizes that skipping doses or not completing the full prescribed course of therapy may decrease the effectiveness of the treatment. Skipping doses is generally associated with a decrease in treatment effectiveness and an increased likelihood of developing bacterial resistance.

Q: What are the signs of a possible allergic reaction to Urisal?

A: Adverse reactions that may signal a possible allergic response include skin rash, hives, and itching, as well as swelling of the face, lips, tongue, or throat. If these are experienced, official guidance notes that medical assessment is warranted.

Q: Is it safe to take Urisal during pregnancy or while breastfeeding?

A: Urisal is classified as Pregnancy Category C by regulatory bodies. Furthermore, the drug is known to be excreted in human milk. Official documents indicate that caution is necessary when the medication is administered to a pregnant or nursing individual.

Q: Does Urisal come in different strengths or forms?

A: Official regulatory product information for Urisal tablets lists the drug as being available in a 1-gram strength for oral administration. The prescribing documentation focuses on this single form and strength.

Q: How long do the effects of Urisal typically last after taking it?

A: Pharmacology studies indicate that the drug is quickly absorbed into the body. Over 90% of the active component is generally excreted in the urine within 24 hours after a single 1-gram dose is administered.

Q: Are there any serious side effects associated with Urisal that are reported?

A: Regulatory documents list documented reactions that may be serious, such as gross hematuria (blood in urine) and bladder irritation. Transient elevations of hepatic enzymes (liver markers) are also reported.

Q: Are there any specific vitamins or supplements that should not be taken with Urisal?

A: The drug’s effectiveness depends on maintaining an acidic urine pH. Therefore, official information states that concurrent use of alkalinizing agents or foods (which may include certain supplements designed to reduce acidity) should be avoided.

Q: Can Urisal be taken at the same time as cold and flu medications?

A: Urisal is strictly contraindicated with sulfonamide medicines. It should also be avoided with any alkalizing agents, which may be found in some cold and flu remedies containing ingredients like sodium bicarbonate.

Q: Is there a generic version of Urisal available?

A: Regulatory product information confirms that the drug, Methenamine Hippurate, is available as a generic product in the 1-gram tablet strength.

Q: Can Urisal be crushed or split if a person has trouble swallowing pills?

A: Official labeling states the tablet is typically swallowed whole. Regulatory context for the active component notes that some formulations must not be crushed as this can affect the function of the medicine.

Q: Is Urisal known to cause drowsiness?

A: The official label for Methenamine Hippurate does not list drowsiness as an adverse reaction. However, one of the active ingredients occasionally associated with the name 'Urisal' in some regulatory documents, Allopurinol, is sometimes reported to impair thinking or reactions.

Q: Can Urisal cause dizziness or affect driving?

A: One of the active ingredients associated with the name 'Urisal' in the source material, Allopurinol, may potentially impair thinking or reactions. Patients taking this drug are typically instructed to be careful when performing activities that require alertness.

Q: Does Urisal contain lactose or gluten?

A: The product label lists the inactive ingredients (excipients) used in the tablets, such as magnesium stearate and silicon dioxide. The complete list of ingredients is detailed in the official prescribing information.

Q: Can Urisal change the color or odor of urine?

A: Regulatory documents list adverse effects such as gross hematuria (blood in urine), particularly with large doses of the drug's components. This occurrence is a documented way the urine color may be changed.

Q: What happens if Urisal is taken with too much water?

A: The drug's activity is dependent on the pH level of the urine. Regulatory context for the active component advises taking the drug with water, which is noted to help avoid irritation of the bladder.

Q: Is Urisal generally considered a non-sedating drug?

A: The official label for Methenamine Hippurate does not list drowsiness as an adverse reaction. However, one of the active ingredients occasionally associated with the name 'Urisal' in some regulatory documents, Allopurinol, is sometimes reported to impair thinking or reactions.

Q: Are there specific symptoms that signal a side effect needs medical attention?

A: Regulatory labels document symptoms that are typically associated with severity and may signal the need for medical assessment. These include gross hematuria (visible blood in urine) and any signs of a severe allergic reaction like facial swelling or hives.

Q: Does Urisal interact with herbal teas or remedies?

A: The effectiveness of Urisal requires an acidic urine pH. Therefore, the restriction of alkalinizing foods and medications is generally recommended in regulatory documents. This constraint may include certain herbal products or teas that could raise the urine pH level.

Q: How quickly does Urisal clear out of the body?

A: Pharmacology studies indicate that the drug's components are rapidly excreted. Over 90% of the active component is generally cleared from the body through the urine within 24 hours after administration of a single 1-gram dose.

How should Urisal be stored and disposed of?

How to Store and Dispose of Urisal (Methenamine Hippurate)

Official regulatory labeling dictates specific conditions for storing Urisal tablets to maintain stability.

Storage Requirements

Condition Regulatory Requirement
Temperature Store at Controlled Room Temperature, defined as 15 C to 30 C (59 F to 86 F). Do not freeze.
Protection Keep in the original, tightly closed, light-resistant container. Protect from moisture and excessive heat.
Child Safety Keep out of the sight and reach of children.

Disposal Instructions

Unused or expired Urisal must be disposed of according to local regulatory requirements. Disposal must not be done via wastewater or household trash, as specified in official product information. Follow official instructions for proper discarding, often by returning to a pharmacist.

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

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