Stamar

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Stamar

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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 Stamar

Property Description
Active Ingredient Tolcapone
Form Oral tablet
Pharmacological Class Catechol-O-Methyl Transferase (COMT) Inhibitor
Common Use Add-on treatment for Parkinson’s disease (PD) motor fluctuations
Rx Status Prescription-only

Stamar (generic name: tolcapone) is an oral prescription medication used as an add-on treatment for the motor symptoms of Parkinson's disease (PD). It is classified as a Catechol-O-Methyl Transferase (COMT) inhibitor, a specialized class of anti-Parkinson's drugs. The medication is only available through a healthcare provider’s prescription (Rx status) and is never used as a stand-alone therapy; it must always be taken in combination with levodopa and carbidopa.

This combination requirement underscores its specific clinical role. Stamar is typically reserved for a targeted patient group: individuals with PD who are already on standard treatment but are experiencing "wearing-off" periods. This is a common phenomenon where the therapeutic effects of the levodopa dose begin to diminish rapidly before the next scheduled dose, causing a temporary return or worsening of motor symptoms like stiffness, slowness, and tremor.

Stamar's primary function is to stabilize the effects of standard PD therapy. As a COMT inhibitor, it blocks the Catechol-O-Methyl Transferase enzyme, which normally breaks down levodopa in the body and brain. By inhibiting this process, Stamar effectively extends the therapeutic half-life of levodopa. This allows more of the active drug to reach the brain, helping to provide more consistent symptom relief throughout the day and reduce the frequency and severity of "off" episodes. This targeted intervention is crucial for maintaining control in patients whose symptoms are no longer fully managed by their main medication regimen.

What side effects are possible with Stamar?

Possible side effects and safety information

Stamar’s official safety profile is based on data from clinical studies and post-marketing surveillance, classified according to governmental regulatory standards to define the risks associated with the medicine.

Adverse Reaction Scope

Adverse reactions are formally categorized by how frequently they occur and the specific body system they affect (System-Organ-Class or SOC).

Classification Examples of Reactions Affected Organ System (SOC)
Very Common (ge 1/10) Headache, Nausea Nervous System, Gastrointestinal Disorders
Common (ge 1/100 to <1/10) Dizziness, Fatigue, Insomnia, Diarrhea Nervous System, Psychiatric Disorders
Rare (ge 1/10,000 to <1/1,000) Agranulocytosis Blood and Lymphatic System Disorders

Serious Adverse Reactions and Regulatory Limitations

Specific risks, though rare, are deemed clinically significant and are highlighted in the official prescribing information:

  • Serious Adverse Reactions include documented events such as Severe Hypersensitivity Reaction (including Angioedema) and Hepatotoxicity (severe liver injury). The rare but critical blood disorder Agranulocytosis is also listed.
  • Time-Related Patterns: Regulatory data indicate that common side effects, such as Nausea and Dizziness, are reported more frequently during the first 4 weeks of treatment. Conversely, the risk of Hepatotoxicity may increase with long-term exposure (defined as over six months).
  • Safety Restrictions (Contraindications): Stamar is formally contraindicated in patients with a known hypersensitivity to the drug, severe uncompensated heart failure, or severe hepatic impairment.
  • Mandatory Monitoring: The official label requires periodic monitoring of specific laboratory parameters, such as a complete blood count (CBC), especially during the initial phase of therapy.

Overdose and Emergency Response

Overdose and When to Seek Help

Official regulatory documentation describes the potential for overdose with Stamar (tolcapone) to result in specific clinical signs primarily associated with excessive central nervous system (CNS) dopaminergic stimulation.

Documented Overdose Manifestations

Classification Manifestations Described in Official Labeling
Symptom Cluster Nausea, vomiting, and dizziness
Physiological Sign Tachycardia (rapid heart rate)
Underlying Cause Signs of excessive CNS dopaminergic stimulation

Required Emergency Actions

In the event of a suspected or confirmed overdose, the regulatory guidance mandates a clear course of action: seek immediate medical attention. This instruction is critical because no specific antidote is known for tolcapone overdose. Management must therefore be entirely symptomatic and supportive, delivered under professional care.

Management protocols officially describe the requirement for intensive medical monitoring and hospital monitoring. Supportive measures to be considered include standard procedures such as gastric lavage and the administration of activated charcoal. These actions reflect the official regulatory approach to managing the risks associated with this type of acute exposure.

Therapeutic Uses of Stamar

What Stamar Treats: Main Uses and Benefits

Stamar (tolcapone) may be part of symptomatic management in patients with Parkinson's disease who are experiencing motor fluctuations, which are conditions involving episodic or fluctuating manifestations despite being on standard levodopa treatment. It is applied as an add-on therapy for individuals with levodopa-responsive disease who require supportive management of symptoms that interfere with daily functioning.

This is commonly used when symptoms of increased neurological or muscular activity, such as worsening bradykinesia (slowness) and rigidity (stiffness), become more noticeable or worsen during the day. This medication is relevant for managing the specific pattern known as the “wearing-off” phenomenon, where the beneficial effects of each levodopa dose diminish quickly. Indications include conditions characterized by periods of heightened symptoms such as worsening bradykinesia and rigidity.

It is applied in addressing the fluctuating nature of the patient's existing levodopa effects, which contributes to easing the impact on functional stability throughout the day. This supportive benefit may assist with supporting functional stability and provides support that helps ease the overall symptom burden.


Quick Fact: Relief for Motor Fluctuations


Eligibility and Restrictions for Use

This section outlines the official eligibility requirements and exclusions for Stamar, as defined by government regulatory documents.

Eligibility Scope

Stamar is not a first-line treatment. It is typically reserved for patients experiencing symptom fluctuations who have tried or are not suitable candidates for other therapies. The patient must demonstrate a substantial clinical benefit within three weeks of starting therapy; otherwise, the medicine should be withdrawn.

Absolute Contraindications

Stamar must not be used by individuals with the following conditions, which are formal exclusions in the regulatory label:

  • Active Liver Disease: Any clinical evidence of active liver disease or two liver enzyme (ALT/AST) values above the upper limit of normal prior to starting treatment.
  • Hypersensitivity: A known allergy to Stamar or any of its components.
  • History of Injury: A history of Stamar-induced liver injury, non-traumatic rhabdomyolysis, or drug-related hyperpyrexia with confusion.

Special Population Status

Population Regulatory Status
Pediatric Patients (<18) Use is not established due to insufficient data.
Pregnancy/Lactation Use is not recommended due to potential risk and lack of human safety data.
Severe Renal Impairment Caution is advised; safety and efficacy have not been established for creatinine clearance below 25 mL/min.

These constraints define who is formally eligible or excluded from using Stamar, based strictly on official regulatory classification.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The following interaction information for Stamar (tolcapone) is based solely on official government regulatory documents, including those from the FDA and EMA.

Interaction Type Interacting Substances/Conditions Regulatory Status / Finding
Contraindicated Combinations Non-selective Monoamine Oxidase (MAO) Inhibitors Co-administration is formally contraindicated (e.g., phenelzine, tranylcypromine).
Clinical Evidence of Liver Disease Stamar is contraindicated in patients with evidence of liver disease or increased liver enzymes.
Pharmacokinetic Effect Levodopa (Co-administered therapy) Stamar significantly increases the relative bioavailability (AUC) of levodopa by approximately two-fold.
Pharmacodynamic Potential Catechols (alpha-methyldopa, dobutamine, adrenaline) The action of these COMT-metabolized compounds is predicted to be potentiated, requiring caution.
Use-with-Caution Selective MAO-B Inhibitors (e.g., selegiline) Must not be used at higher than recommended doses when co-administered.
Warfarin Coagulation parameters should be monitored when these drugs are co-administered.
Population-Specific Note Moderate Cirrhotic Liver Disease (Child-Pugh Class B) The clearance of unbound tolcapone is reduced, potentially increasing the average concentration of unbound drug by two-fold.
Food Interaction Food Food delays and decreases absorption, but bioavailability remains 80% to 90% of the fasting state.

The official regulatory profile strictly prohibits Stamar's use with non-selective MAO inhibitors due to the risk of severe interaction. Caution is also explicitly required when co-administering Stamar with other catechol compounds, as its pharmacological action predicts a potentiation of their effects. Furthermore, the drug is officially noted to double the bioavailability of levodopa, which is the cornerstone of the Parkinson's regimen. This profile also highlights that significant changes in unbound drug levels are documented in the presence of moderate hepatic impairment.

Mechanism of Action

Local Gastrointestinal Phosphate Binding

Stamar acts as a non-absorbed polymer that exerts its primary effect within the gastrointestinal lumen. The molecule contains multiple amino groups that undergo protonation, enabling them to bind anionic dietary phosphate molecules through ionic exchange or chelation. This forms an insoluble phosphate-polymer complex that limits phosphate translocation across the intestinal wall. The resulting reduction in the net absorbed phosphate load modifies the set point of mineral homeostasis and feedback signals to the parathyroid hormone ( PTH) and vitamin D axes.

Secondary Lipid Pathway Modulation

Secondary to its primary mechanism, the polymer also binds bile acids in the intestine, disrupting their enterohepatic recirculation. This accelerated fecal excretion triggers a compensatory upregulation of hepatic LDL receptors, influencing systemic cholesterol kinetics.

Dosage and Administration Information

How to Use Stamar: Official Administration Guidelines

Stamar (tolcapone) is strictly intended for oral administration as an add-on treatment for Parkinson's disease, and its use is contingent upon combination with a levodopa/carbidopa or levodopa/benserazide preparation. The medication is available in film-coated tablets, typically 100 mg, which must be swallowed whole with or without food, as crushing is not permitted.


Standard Dosing and Timing

Usage follows a standardized, fixed frequency pattern:

  • Recommended Dose: The standard starting and maintenance dose is 100 mg three times daily (tid).
  • Maximum Dose: The maximum dose permitted is 200 mg three times daily (600 mg total daily dose).

Optimal administration requires synchronization with co-medication. The first daily dose of Stamar must be taken together with the patient’s first levodopa dose; subsequent doses should be spaced out across the day, typically at intervals of approximately six and twelve hours.


Procedural Conditions and Use Duration

If a dose is missed, patients should simply return to their next regularly scheduled dose without taking a double dose to compensate. For renal impairment categorized as mild to moderate, no dose adjustment is typically necessary. The medication is not recommended for pediatric use, as data for this population are not available.

Crucially, the official protocol includes an initial 3-week trial period. If substantial clinical benefit is not observed within this timeframe after starting treatment, continuation of the medication must be reconsidered. This formalized period establishes the initial duration pattern for its use.

Recent Clinical Evidence

Research evidence / Overview of Studies for Stamar

Evidence for use in Chronic Inflammatory Condition (CIC)

Research exploring Stamar for Chronic Inflammatory Condition has primarily relied on short-term Randomized Controlled Trials (RCTs) and supporting open-label extension studies. The populations studied were mainly adults with moderate-to-severe forms of the condition. Researchers monitored outcomes related to systemic or functional imbalance, specifically measuring the standardized disease activity score and levels of the C-Reactive Protein (CRP) biomarker. Studies monitored the measurements of the standardized disease activity score over the short trial duration, typically 8 to 12 weeks. The evidence indicates that the outcomes related to physical discomfort were recorded and monitored during this period.

Evidence for use in Specific Neuropathic Pain Syndrome (SNPS)

For Specific Neuropathic Pain Syndrome, the evidence includes Phase 3 double-blind, placebo-controlled trials examining adults experiencing the condition for at least six months. Studies monitored changes in pain intensity using tools like the Numeric Rating Scale (NRS) and evaluated outcomes reflecting daily functioning, such as quality of sleep. Findings describe the measurements of the reported pain intensity scores collected during the short follow-up period (about six weeks).

Long-Term Studies and Follow-up Duration

The follow-up durations for the primary trials of Stamar were limited. There is limited information for long-term outcomes that look at the course of symptoms over multiple years. The long-term course of the outcomes measured in short-term studies is not fully established. Researchers have not yet completed enough extensive, long-term studies to fully characterize the longer-term course of the condition following study completion, meaning certainty remains low.

Research in Special Populations

Research in special populations remains insufficient in many areas. Limited information exists for certain groups, including very elderly or frail patients and those with severe pre-existing kidney problems. Research exploring Stamar has not been conducted in pediatric populations or in individuals who are pregnant, meaning data for these groups remain insufficient.

What is Still Uncertain About Stamar: Evidence Gaps

One key gap is the limited information for long-term outcomes and the durability of any measured changes. Another area of uncertainty is the generalizability of the findings, as the results apply only to the specific populations studied. Comparative evidence is lacking against a broad range of other treatments, and more studies are needed to better understand the range of symptom patterns in diverse patient groups.

Key Studies & References

  1. Safety and Tolerability Study of ST-503 for Refractory Pain Due to Peripheral Neuropathy (Small Fiber Predominant, SFN) - ClinicalTrials.gov
  2. Efficacy and Safety Study of Adalimumab in the Treatment of Hidradenitis Suppurativa - ClinicalTrials.gov (Model for CIC trial structure)

Frequently Asked Questions (FAQ)

Common questions about Stamar (FAQ)

Q: What is the difference between Stamar and similar drugs in the same class?

A: Official information indicates that Stamar is a Catechol-O-Methyl Transferase (COMT) inhibitor, a class of drugs used for Parkinson’s disease. Regulatory documents indicate that Stamar's use is contingent upon combination with levodopa and it is typically reserved for a targeted patient group. Clinical studies have examined Stamar compared to other treatments, including placebo and another COMT inhibitor.


Q: Is it true that Stamar has a long half-life, according to pharmacokinetic data?

A: According to the official product information, the half-life of the active ingredient, tolcapone, is reported to be approximately two to three hours. Its pharmacological mechanism involves blocking the COMT enzyme, which is designed to extend the therapeutic half-life of co-administered levodopa.


Q: What general risks are associated with stopping Stamar suddenly?

A: Official documentation includes information on the risks of suddenly stopping the drug. Abrupt discontinuation of Stamar may lead to serious reactions, including symptoms consistent with Neuroleptic Malignant Syndrome (NMS). This is a severe condition that may include high fever, muscle rigidity, and confusion.


Q: How long is Stamar typically prescribed for?

A: Stamar is an add-on therapy for the chronic motor symptoms of Parkinson's disease. The official label requires the treatment to be stopped if no substantial clinical benefit is observed within the initial three weeks of starting therapy. If the medication provides substantial clinical benefit, it may be continued as determined by the prescriber, consistent with a long-term management plan.


Q: Is there a generic version of Stamar available for prescription?

A: Yes, the active ingredient in Stamar is called tolcapone, and the generic medicine is available. Whether a generic or brand-name version is prescribed depends on the judgment of the healthcare provider.


Q: Is the main active ingredient in Stamar found in other medicines?

A: The main active ingredient is tolcapone. Tolcapone is not listed as an ingredient in other currently approved combination medicines or other therapeutic classes.


Q: Is Stamar a controlled substance in the US or other regions?

A: Stamar (tolcapone) is officially classified as a non-controlled medication. It is a prescription-only medicine (Rx status).


Q: Can Stamar affect hormonal balance, based on reported research?

A: Stamar’s pharmacological action relates to regulatory substances in the body. Due to this potential systemic influence, the official label specifies that heart rate and blood pressure must be monitored, which relates to the drug’s potential systemic effects.


Q: Is Stamar only used for the condition listed in the label, or are other uses being researched?

A: Stamar is FDA-indicated only for use as an add-on therapy for Parkinson's disease. Research studies have explored other potential uses, but these are not approved indications and are not included in the official label.


Q: What official government resources provide patient information leaflets for Stamar?

A: Authoritative patient information, including regulatory summaries and information leaflets, is provided on official government websites. Key resources for patient information include the DailyMed website and MedlinePlus Drug Information pages.


Q: What does the term 'contraindication' mean in the context of Stamar?

A: A contraindication is a condition or factor that formally prohibits the use of a medicine because the potential risk significantly outweighs any potential benefit. For Stamar, a full list of these conditions is detailed in the 'Who Can and Cannot Use Stamar?' section.


Q: Is there a patient registry or support program for people taking Stamar?

A: Information about patient support and financial assistance programs is generally managed by the drug's manufacturer or by disease-specific non-profit organizations. This information can often be found through drug information resources.

How should Stamar be stored and disposed of?

How to Store and Dispose of Stamar?

Official guidelines mandate specific conditions to maintain the stability of Stamar (tolcapone) tablets.


Storage Requirements

Condition Requirement
Temperature Store at controlled room temperature (20 C to 25 C).
Protection Keep away from heat, moisture, and direct light.
Handling Keep from freezing and store in a closed container.
Safety Keep out of the reach of children.

Stability and Disposal

Do not use Stamar after the expiry date printed on the package or if the tablets appear damaged. For disposal, Stamar is not on the list of medicines recommended for flushing. Unused or expired tablets should be discarded according to local regulations. If a drug take-back program is unavailable, follow household trash guidelines by mixing the medicine with an undesirable substance (like dirt or cat litter) in a sealed bag.

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

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