Stonex

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Stonex

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Method of action: Anti-Inflammatory

Medically reviewed

Marina Burgos

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 Stonex

What is Stonex? (Ursodeoxycholic Acid)

The following provides an authoritative, fact-checked overview of the identity, classification, and general purpose of the medicine Stonex.

Property Description
Active ingredient Ursodeoxycholic Acid (UDCA), or Ursodiol
Form Capsule, Tablet, or Liquid Suspension
Pharmacological class Bile Acid Preparation, Gastrointestinal Agent
Route of administration Oral route
Origin Naturally-occurring secondary bile acid (utilized synthetically)

What Type of Medicine is Stonex (Ursodeoxycholic Acid)?

Stonex is a prescription-only medication whose active component is the single substance Ursodeoxycholic Acid (UDCA), also known as Ursodiol. This product is classified as a Bile Acid Preparation, a Gastrointestinal Agent that is clinically recognized for its choleretic (promoting bile flow) and anticholelithogenic (preventing gallstone formation) properties. Ursodeoxycholic Acid is structurally identified as a secondary bile acid that naturally constitutes a minor fraction of the human bile acid pool.

Its unique chemical identity as a highly hydrophilic (water-soluble) bile acid allows it to effectively displace more toxic, fat-soluble bile acids from the internal bile circulation when administered orally. This action of substituting toxic compounds is central to the compound's general use in promoting biliary health and treating cholestatic conditions. UDCA is used to improve bile flow and protect liver cells from bile acid toxicity.


Composition, Forms, and General Therapeutic Purpose

Stonex is a single-ingredient product, containing only Ursodeoxycholic Acid combined with necessary excipients required for formulation stability. It is typically available in various dosage forms, including capsules and tablets, as well as sometimes a liquid medicine (suspension), all intended for the oral route of administration. The general therapeutic purpose of Stonex is to chemically modify the composition of bile.

This modification is achieved primarily by reducing the bile's cholesterol saturation by inhibiting cholesterol absorption and secretion, and by exerting a cytoprotective effect on the cells lining the liver and bile ducts. The therapeutic action of Ursodeoxycholic Acid facilitates the dissolution of cholesterol gallstones by changing the lithogenicity of bile. This means the drug helps stabilize bile chemistry to discourage the formation of gallstones and assists in dissolving existing ones.

Regulatory References

  1. EMA Classification

What side effects are possible with Stonex?

Possible side effects and safety information

The safety profile of Stonex (Ursodeoxycholic Acid) is documented through regulatory review, classifying potential adverse reactions by frequency and affected body systems.

Officially Documented Adverse Reactions

Side effects are primarily centered on the gastrointestinal system and hepatobiliary function. Diarrhea or loose stools are classified as Common adverse reactions, meaning they may affect up to 1 in 10 people according to official labeling. Other frequently documented effects include abdominal discomfort, abdominal pain, nausea, rash, and temporary hair thinning (alopecia).

System-Organ Class Examples of Officially Listed Adverse Reactions
Gastrointestinal disorders Diarrhea, abdominal pain, constipation, vomiting
Hepatobiliary disorders Aggravation of pre-existing jaundice
Skin and subcutaneous tissue Pruritus (itching), rash, alopecia
Immune System Disorders Drug hypersensitivity reactions (e.g., urticaria)

Serious Safety Considerations

Official regulatory documents identify certain events as rare but serious. These include the decompensation of hepatic cirrhosis in patients with advanced primary biliary cirrhosis, an event that is noted as Very Rare and may partially ease upon discontinuation. The development of calcified gallstones, which are difficult to treat, is also documented as a Very Rare occurrence. Severe manifestations of drug hypersensitivity, such as angioedema, are also listed.

Population and Monitoring Constraints

The regulatory label includes specific constraints for use. The medicine should be avoided during pregnancy unless absolutely necessary, and women of child-bearing potential are instructed to use non-hormonal contraception. For patient safety, liver function tests (e.g., ALT, AST, bilirubin) must be monitored monthly during the initial three months of therapy and periodically thereafter. The medicine is contraindicated in patients with a non-functioning gallbladder or complete biliary obstruction.

Overdose and Emergency Response

Overdose and when to seek help

The official regulatory documentation for Stonex (Ursodeoxycholic Acid) establishes the drug's overdose profile based on its high safety margin and reduced absorption at excessive doses, which limits systemic risk.

Overdose Scope Official Regulatory Documentation
Documented Overdose Manifestations The primary and most frequently documented clinical sign of overdosage is diarrhea and the passage of loose stools.
Serious/Life-Threatening Outcomes Serious adverse effects are generally unlikely to occur, and human cases of severe, life-threatening overdose are not reported in official prescribing information due to reduced intestinal absorption at high doses.
Emergency-Response Statements Seek emergency medical treatment for any suspected overdose. Contact a poison control center or emergency services if the individual exhibits severe, generalized symptoms like collapse or difficulty breathing.

Resulting Overdose Structure

Official overdose statements:

  • Diarrhea is the most prominent documented manifestation, resulting from the presence of high concentrations of the substance in the bowel lumen.
  • No specific antidote is known for this overdose; management is symptomatic and supportive, primarily to address the gastrointestinal effects.
  • The procedural step of monitoring liver function tests is officially required during the management of an overdose situation.
  • Ion-exchange resins are an officially described supportive measure that may be considered to bind excess bile acids in the intestine.

The regulatory profile mandates that patients must contact medical professionals for immediate management and necessary observation. This ensures all required supportive care is implemented, regardless of the classification of the overdose risk.

Therapeutic Uses of Stonex

Quick Facts

  • Primary Focus: May be used to support renal (kidney) and urinary tract function.
  • Associated Use: Assists in the management of urolithiasis (urinary tract stones) and helps reduce the formation of certain stone components.
  • Additional Support: Is associated with promoting relief from related urinary discomfort and assists in maintaining a balanced urine flow.

What Stonex Treats: Main Uses and Benefits

Stonex is a formulation that may offer support for the health of the renal and urinary systems. Its primary use is in the management of renal and urinary tract calculi (stones). The components are associated with potential support in dissolving existing urinary stones and may help minimize the conditions conducive to the formation of new stones.

Consistent use of this formulation is utilized to promote the body’s natural process for stone expulsion. Furthermore, Stonex may contribute to the relief of general urinary discomfort, such as a burning sensation during urination, and helps maintain the normal flow of urine. It is also an option considered for supportive care during the management of certain urinary tract concerns.

Eligibility and Restrictions for Use

Who can and cannot use Stonex?

Regulatory authorities strictly define the population eligibility for Stonex (Ursodeoxycholic Acid) based on age, physiological status, and coexisting medical conditions. The medicine is approved for use in adults diagnosed with Primary Biliary Cholangitis (PBC) and is indicated for the dissolution of radiolucent (non-calcified) cholesterol gallstones. Eligibility for pediatric use is limited and generally not established for the general population; approval exists only for children aged 6 to 18 years for hepatobiliary disorders associated with cystic fibrosis.


Stonex is contraindicated and must not be used by specific populations. This includes individuals with a known hypersensitivity to bile acids or any component of the formulation. Absolute prohibitions apply to patients with active gastric or duodenal ulcers, acute inflammation of the gallbladder, or a non-functioning gallbladder. Contraindication also applies to patients with decompensated liver cirrhosis, biliary tract obstruction, or calcified gallstones. The medicine is prohibited during pregnancy, and women must use effective non-hormonal contraception during therapy. It is not recommended for women who are breastfeeding.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official interaction profile for Stonex (Ursodeoxycholic Acid/UDCA) is defined by documented effects that either reduce the drug's intestinal absorption or counteract its intended efficacy. Regulatory authorities classify these interactions as generally requiring either administration timing constraints or combination avoidance.

Interaction-Related Restrictions

Interaction Category Specific Interacting Substances Regulatory-Stated Outcome
Exposure-Modifying Bile Acid Sequestering Agents (e.g., Cholestyramine, Colestipol) Significantly reduces absorption of Stonex by binding it in the intestine.
Timing-Separation Rule Aluminum-based Antacids and Sequestering Agents Requires administration to be separated by at least two hours to prevent reduced absorption.
Counter-Therapeutic Estrogens, Oral Contraceptives, Clofibrate-class agents Agents increase cholesterol secretion, which counteracts the intended efficacy of Stonex.
Substance Interaction Alcohol Advised to be avoided as it may interfere with the medicine's liver-supporting action.

The core interaction structure for Stonex centers on preventing two primary outcomes: reduced exposure due to intestinal binding and reduced efficacy due to pharmacodynamic effects. There are no commonly cited metabolic enzyme (CYP) or transporter-mediated interactions listed in major regulatory documentation. Adherence to timing separation for binding agents and avoidance of counter-therapeutic lipid-altering drugs represent the primary constraints defined in the product labeling.

Mechanism of Action

Dual Inhibition of Key Kinase Pathways

Stonex is classified as a multi-kinase inhibitor, primarily blocking the activity of intracellular enzymes MEK1 and MEK2 within the MAPK cascade, while also suppressing cell-surface Receptor Tyrosine Kinases (RTKs) such as VEGFR and PDGFR. This dual-level blockade initiates a signaling cascade that limits the transmission of proliferative and survival messages within the cell, resulting in the physiological effect of attenuated growth signaling. This blockade is the core biological action that shapes the drug’s observed effect profile. This strategy results in the suppression of multiple components within the growth and survival signaling networks.

Suppression of Cell Proliferation and Angiogenesis

By inhibiting these core pathways, Stonex supports the regulation of two critical physiological processes: cell proliferation and angiogenesis (new blood vessel formation). The drug’s action disrupts the cell cycle, decreasing the rate of cell division and promoting programmed cell death (apoptosis). Simultaneously, the block on VEGFR and PDGFR signaling reduces the ability of the surrounding environment to form the necessary vascular support and contributes to the structural modification of existing vasculature. This non-proliferative mechanism of action complements the direct internal cell-cycle interference.

Dosage and Administration Information

How to Use Stonex (Ursodeoxycholic Acid)

The administration of Stonex, whose active ingredient is Ursodeoxycholic Acid (UDCA), is characterized by specific parameters detailing dose, frequency, and intake conditions. This medicine is for the oral route of administration, available in forms such as capsules, tablets (e.g., 250 mg to 500 mg strengths), and oral suspension.

Dosing and Frequency

Standard regimens are typically based on the patient's weight and the condition being managed. For the long-term management of Primary Biliary Cholangitis (PBC), the adult dose is generally 13-15 mg/kg of body weight daily. This total daily dose is typically administered in two to four divided portions (doses).

For the dissolution of cholesterol gallstones, the prescribed dose ranges from 8-12 mg/kg per day, and is often administered as a single evening or bedtime dose to optimize the medication's effect on bile composition overnight. Gallstone prevention in specific contexts may require a fixed 300 mg dose taken twice daily.

Administration Requirements

To ensure proper absorption, Stonex is taken with food. Solid dosage forms, such as tablets and capsules, are swallowed whole with water. They should not be crushed or chewed, though some scored tablets are designed to be broken in half for dose adjustment. The timing of administration also requires procedural separation from certain other medications: Stonex is taken at least two hours apart from bile acid sequestrants or aluminum-based antacids to prevent these agents from binding to and reducing the medicine’s absorption.

Course Duration and Adjustments

Treatment for gallstone dissolution requires a long-term commitment, typically spanning 6 to 24 months, and is continued for several months after dissolution is confirmed. For PBC, the therapy is often considered chronic. Specific, weight-based pediatric dosing (20-30 mg/kg/day) is defined for use in Cystic Fibrosis-associated conditions. If a dose is missed, the regular schedule is resumed with the next dose, and a double dose is not taken to compensate.

Recent Clinical Evidence

Research evidence / Overview of studies for Stonex

The clinical evaluation of Stonex (Ursodeoxycholic Acid) is based on findings from official research, including Randomized Controlled Trials (RCTs) and systematic reviews. This research explores the agent's observation in specific adult populations and contributes to the broader evidence landscape for its established uses.


Evidence for Use in Primary Biliary Cholangitis (PBC)

Studies monitored adult patients with PBC across various disease stages. Research examined outcomes related to systemic or functional imbalance, tracking changes in specific liver enzyme biomarkers. Long-term follow-up studies monitored endpoints related to death or liver transplantation in patients receiving the agent compared to those receiving placebo. Research provides context but not individual predictions about patient outcomes.


Evidence for Gallstone Dissolution and Prevention

Stonex was studied for the dissolution of certain gallstones and for prevention in high-risk groups. Trials included adults with cholesterol-rich stones or those undergoing rapid weight loss. Research examined endpoints such as the rate of stone disappearance (measured by imaging) and the incidence of new gallstone formation. Findings describe patterns where the agent coincided with imaging observations related to stone disappearance and differences in the measured rate of new stone detection.

The results apply only to the populations studied, specifically those with cholesterol-rich stones or post-bariatric surgery patients. Long-term outcomes related to gallstone recurrence after dissolution therapy is not fully established.


Research Gaps and Uncertainties

Data for certain groups remain insufficient, and certainty is lower for outcomes not directly related to the regulated indications, such as in pediatric patient groups. Comparative evidence is limited against some alternative agents. Subgroup findings for different levels of disease severity are uncertain.

Frequently Asked Questions (FAQ)

Common questions about Stonex (FAQ)

Q: How quickly does Stonex typically start to work?

A: Studies indicate that for gallstone dissolution, the change in bile composition necessary for the medicine to work reaches its steady-state concentration in the bile acid pool after approximately three weeks of consistent dosing. Achieving the therapeutic goal, such as dissolving gallstones, is a long-term process that can take many months, and the full course of treatment is required.

Q: What happens if I miss a dose of Stonex?

A: Official product information states that if a dose is missed, it should be taken as soon as it is remembered. However, if it is already close to the time for your next scheduled dose, the missed dose should be skipped, and you should continue your regular schedule. The product information clearly instructs against taking a double dose to make up for a missed dose.

Q: Can Stonex cause headaches?

A: Yes, headaches are listed as an officially documented adverse reaction that was observed in clinical trials. Persistent headaches or any unwanted effects should be discussed with a healthcare professional.

Q: Can older adults safely use Stonex?

A: Clinical trials for the approved uses of Stonex were conducted in the adult patient population. Official constraints list contraindications such as decompensated hepatic cirrhosis. These conditions, not age alone, define eligibility, and a physician determines the appropriateness of the treatment.

Q: Is Stonex safe for children?

A: The use of Stonex for the general pediatric population is not established. However, the medicine has specific approval and established dosing for children aged 6 to 18 years who are managing certain hepatobiliary disorders associated with cystic fibrosis.

Q: Is Stonex safe to take if I have kidney problems?

A: Regulatory documents do not list kidney impairment as a major contraindication or require routine renal function monitoring. The primary safety constraints and monitoring are focused on liver function and existing biliary conditions.

Q: Can people with liver issues take Stonex?

A: Stonex is used to treat a specific chronic liver disease, Primary Biliary Cholangitis (PBC). However, it is contraindicated and should not be used by patients with decompensated hepatic cirrhosis, active gastric or duodenal ulcers, or acute gallbladder inflammation.

Q: Does Stonex make you drowsy?

A: Drowsiness (somnolence) is not explicitly listed as a routine side effect in the official product label. However, related effects such as dizziness and fatigue have been officially reported in clinical data. Additionally, insomnia (difficulty sleeping) is also a reported adverse reaction.

Q: Will Stonex affect my ability to drive or operate machinery?

A: The official product information states that no specific effect on the ability to drive or use machines is known. However, if you experience side effects like dizziness or fatigue, it is advisable to exercise caution if these effects are experienced.

Q: How can I tell if a side effect from Stonex is serious?

A: The regulatory documents classify certain events as serious, although they are very rare. These include the decompensation of advanced liver cirrhosis or signs of a severe allergic reaction, such as angioedema. Any reaction that is concerning, severe, or potentially an allergic reaction requires immediate attention from a healthcare provider.

Q: Does Stonex need to be stored in the refrigerator?

A: No, Stonex should be stored at room temperature, typically not exceeding 30 C (86 F). Official instructions also strictly advise that the medicine must be protected from heat and moisture and should never be frozen.

Q: Is it normal to feel a bit dizzy after taking Stonex?

A: Dizziness is listed in the official product information as an adverse reaction that has been reported in clinical trials. Dizziness or any similar nervous system effects are reasons to consult a healthcare professional.

Q: Are there any long-term side effects associated with Stonex use?

A: Since Stonex is often used for chronic, long-term conditions, adverse reactions are monitored over time. The regulatory information requires periodic checks of liver function during long-term therapy, especially in the initial months, to help ensure patient safety.

Q: Are there any vitamins or supplements I should avoid while on Stonex?

A: The regulatory label primarily warns against certain drug classes, such as bile-acid-binding substances and estrogens. It is always recommended to inform a doctor or pharmacist about all vitamins, nutritional supplements, and herbal products being used, as potential interactions may need to be considered.

Q: Does Stonex help with pain relief?

A: Stonex is a bile acid preparation primarily indicated for specific liver conditions and the dissolution of certain gallstones. Its established uses and approved indications do not include general pain relief or use as a dedicated analgesic medication.

Q: Is there a generic version of Stonex available?

A: Yes, the active ingredient in Stonex, which is Ursodeoxycholic Acid (often called Ursodiol), is widely available as a generic product in various dosage forms.

Q: Where can I find research studies or clinical trials on Stonex?

A: Official clinical trials for Stonex can be found by using public, government-run resources, such as the ClinicalTrials.gov website. Further scientific reviews and data are often available through the National Institutes of Health (NIH).

Q: Are there any dietary restrictions while taking Stonex?

A: Official administration requirements state that the medicine should be taken with food to ensure proper absorption. Additionally, alcohol use is advised against as it may interfere with the medicine's liver-supporting action.

Q: Does Stonex have any effect on sleep?

A: Yes, according to official adverse reaction data, insomnia (difficulty sleeping) is a reported side effect of Stonex in clinical trials.

Q: Is it true that Stonex can affect birth control pills?

A: The regulatory label advises women of child-bearing potential to use effective non-hormonal contraception. This is because oral contraceptives and other estrogen-containing agents may counteract the intended efficacy of Stonex.

Q: Can Stonex affect my blood pressure?

A: Changes in blood pressure are not listed as a common or routine side effect in the official product labeling. Any concerns regarding blood pressure while on this medication should be directed to a healthcare provider.

Q: Can I stop taking Stonex as soon as I feel better?

A: Treatment should not be stopped without guidance. Therapy for conditions like gallstone dissolution is typically long-term, often lasting many months, and is often continued for a period even after symptoms or signs of improvement appear. Stopping treatment early without medical guidance may increase the risk of the condition returning.

Q: Does Stonex have a sedative effect?

A: Stonex is not classified as a sedative medication. However, official data reports side effects such as fatigue and dizziness. Excessive sedation or fatigue are symptoms that require guidance from a healthcare professional.

Q: Does Stonex interact with herbal teas?

A: Specific herbal teas are not listed in the regulatory documents for interactions. However, it is recommended to inform your doctor or pharmacist about all herbal products you are using to check for potential interactions.

Q: Does Stonex affect the results of any lab tests?

A: Yes, the medication can affect liver function markers. For patient safety, the regulatory label requires that liver function tests (such as ALT, AST, and bilirubin) be monitored monthly during the first three months of therapy and periodically thereafter.

Q: What is the molecular formula of the active ingredient in Stonex?

A: The active ingredient in Stonex is Ursodeoxycholic Acid. Its molecular formula is C24 H40 O4, which confirms its identity as a secondary bile acid.

Q: How long does Stonex stay in your system after the last dose?

A: When treatment is stopped, the concentration of the active ingredient in the bile acid pool decreases over time. It typically declines to about 5% to 10% of its therapeutic level in approximately one week after the last dose.

How should Stonex be stored and disposed of?

Official Storage and Disposal Requirements for Stonex (Ursodeoxycholic Acid)

The storage and disposal instructions for Stonex (Ursodeoxycholic Acid/Ursodiol) are strictly defined by regulatory documents to maintain product integrity and safety.

Classification Official Regulatory Wording
Storage Condition Type Room temperature, Protect from heat and moisture, Do not freeze.
Temperature Requirements Store at a temperature not exceeding 30 C [FDA Verification Portal].
Container/Packaging Rules Keep in the original container/package and ensure the container is tightly closed.
Child Protection Keep out of the reach and sight of children; always lock safety caps on containers.
Disposal Guidelines Dispose of medicine through a drug take-back program or by mixing with an unappealing substance in a sealed bag for trash. Do not flush down the toilet.

Storage mandates keeping the product in its original, tightly closed container at room temperature, while explicitly prohibiting freezing or excessive heat and moisture. Disposal requires adherence to guidelines, prioritizing official take-back options, and universally enforcing child-protection measures by storing the medication out of reach.

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

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