Silomat

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Silomat

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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 Silomat

Defining Silomat: Classification and Composition

Silomat is a medication with the active ingredient Clobutinol hydrochloride. It is classified as a synthetic non-opioid antitussive agent, a category of medicine used to suppress the involuntary cough reflex. This compound functions as a cough suppressant, meaning its primary purpose is to reduce the frequency and intensity of coughing through its action on the nervous system.

The compound, Clobutinol, is chemically defined as a piperidine derivative, which characterizes its nature as a synthetically developed compound. This classification distinguishes its action on the cough reflex as occurring through non-narcotic pathways, separating it structurally from opioid-based antitussives. Silomat is typically presented as a single active ingredient product, formulated with a base vehicle such as an aqueous or non-alcoholic syrup or a fatty base for suppositories.


Physical Forms and General Therapeutic Purpose

Clobutinol is prepared in various dosage forms, including oral syrup, drops, and coated tablets, as well as suppositories. These allow for delivery via the oral and rectal routes of administration. This variety in form provides options for different patient needs, such as those who have difficulty swallowing tablets or require alternative absorption profiles.

Its general purpose is to provide symptomatic relief from a dry, unproductive cough, which is the type of cough often associated with irritation during acute respiratory tract infections. Clobutinol’s mechanism involves a central action on the brain's cough center, which raises the threshold at which the involuntary reflex occurs. This action addresses the neurological urge to cough, providing relief in situations where a persistent cough may be interrupting rest.

What side effects are possible with Silomat?

Possible Side Effects and Safety Information for Silomat (Butamirate Citrate)

This information describes the documented adverse reactions and safety restrictions for Silomat, based on official governmental regulatory labeling. It does not contain dosage instructions or advice.

Adverse Reaction Classification

Side effects are officially classified by the frequency of their occurrence:

Frequency Examples of Documented Side Effects
Rare (1 in 1,000 to 1 in 10,000 users) Drowsiness, Nausea, Diarrhoea, Urticaria (hives)
Very Rare (Fewer than 1 in 10,000 users) Hypersensitivity reactions (e.g., Angioedema)

These effects are typically categorized by the body system affected:

  • Nervous System Disorders: Includes drowsiness and dizziness.
  • Gastrointestinal Disorders: Includes nausea and diarrhoea.
  • Immune System and Skin Disorders: Includes rare occurrences of hypersensitivity and rashes.

Serious Adverse Reactions

While rare, the regulatory profile includes reports of severe hypersensitivity, such as Angioedema (sudden swelling). It is noted that certain products previously marketed under the Silomat brand name (containing clobutinol) were withdrawn in some countries due to cardiac safety concerns (QT interval prolongation), a critical regulatory safety history associated with the trade name.

Population-Specific Safety Statements

Official labels detail restrictions for certain groups:

  • Pregnancy and Lactation: Use is generally contraindicated during the first three months (first trimester) of pregnancy. Use in the second and third trimesters, or while breastfeeding, requires strict medical assessment due to unknown risks.
  • Operating Vehicles or Machinery: Due to the rare potential for drowsiness, patients are cautioned about performing activities requiring full alertness after taking the medicine.

Treatment is typically intended for short-term use only, and the label specifies contraindications for patients with known hypersensitivity to butamirate citrate or its inactive ingredients.

Overdose and Emergency Response

Overdose and When to Seek Help

The official regulatory profile for Silomat (clobutinol hydrochloride) overdose is defined by the severe, dose-dependent risks identified during its authoritative assessment.


Overdose Scope and Manifestation

Excessive exposure to clobutinol is formally documented to result in QT/QTc interval prolongation, a clinical manifestation of cardiovascular toxicity. This effect is considered clearly dose-dependent, meaning the risk increases with higher levels of intake. This alteration to the heart's electrical activity carries the potential for a potentially life-threatening Torsades de Pointes arrhythmia, which is a serious, rapid heart rhythm disorder. Regulatory documentation indicates that no specific antidote is described for this particular form of cardiac toxicity.


Required Emergency Response

When overdose is suspected, or if any symptoms consistent with severe cardiac changes occur, immediate medical attention must be sought. Due to the high-risk nature associated with the dose-dependent cardiotoxicity, regulatory bodies require actions that emphasize urgency. Management is focused on symptomatic and supportive care. Continuous Electrocardiogram (ECG) monitoring is necessary for observation, allowing medical professionals to detect and manage changes in the QTc interval and potential proarrhythmic events.


Connection to the Official Profile

The official overdose structure is constrained entirely by the severity of the dose-dependent QT interval prolongation. This specific effect establishes the risk level, classifying the potential outcome as a life-threatening ventricular arrhythmia. This classification dictates the need for immediate medical intervention and specialized continuous cardiac monitoring as the only mandated emergency actions detailed by regulatory authorities.

Therapeutic Uses of Silomat

What Silomat Treats: Main Uses and Benefits

Silomat (clobutinol hydrochloride) is commonly used to help with the symptomatic relief of cough. The core therapeutic focus is applied across domains where additional symptomatic support is needed to address specific manifestations of the cough reflex.

Targeted Symptoms and Indications

The medication is commonly used for managing conditions characterized by periods of heightened symptoms, such as acute respiratory tract infections. It is primarily relevant for easing the dry, unproductive, and persistent cough, which are symptoms that create noticeable physiological strain. It may be part of symptomatic management to address pronounced manifestations of cough, particularly those that lead to disruptive nocturnal episodes. The medication's use is within therapeutic areas involving heightened responses and helps address symptoms related to irritative states.

Practical Benefit and Clinical Context

Silomat may be part of symptomatic management in acute clinical settings where pronounced symptoms create temporary functional strain. It is applied in scenarios where short-term symptomatic assistance is needed to help with easing difficult, episodic symptoms, such as the non-productive cough following a common cold, for adult and older adult patients. This supports patients during difficult episodes by easing distress and assists with maintaining functional stability.


Quick Fact: Relief for Dry, Irritating Cough

Eligibility and Restrictions for Use

Who Can and Cannot Use Silomat?

The population eligibility for Silomat (clobutinol hydrochloride) is strictly defined by the regulatory status of the medication. Official health authorities, including the European Medicines Agency (EMA), have determined that the risks of the medicine outweigh the benefits, leading to a recommendation for the withdrawal of marketing authorizations globally.


Absolute Contraindications

Use of Silomat is absolutely prohibited in patients with established or suspected risk factors for severe cardiac events, as documented in regulatory findings. This includes populations with:

  • Known or suspected prolongation of the QT interval (a measure of the heart's electrical cycle).
  • A predisposition to developing the serious heart rhythm disturbance known as Torsades de pointes.
  • Specific cardiac conduction disorders, such as congenital Long QT Syndrome.

Age-Group Eligibility and Limitations

No age group is explicitly approved for the use of Silomat under current regulatory standards due to the global withdrawal action.

  • Children and Adolescents: Use is not recommended. The critical safety concern leading to regulatory action was first identified in the pediatric population.
  • Adults and Older Adults: Use is not permitted, as the core cardiac safety risk applies across all ages, resulting in the prohibition from the market.

Official Eligibility Status

The regulatory severity classification for this medicine is characterized by an Absolute Contraindication for specific cardiac risk populations and a global Recommended Revocation of Marketing Authorisation for the general population. Specific eligibility rules regarding pregnancy or lactation are not detailed in final regulatory withdrawal notices.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The regulatory interaction profile for clobutinol hydrochloride (Silomat) is strictly defined by its established pharmacodynamic risk of delaying ventricular repolarization, which led to restrictions and market withdrawal decisions by government health authorities.

Interaction Scope and Constraints

The most significant interaction is the additive effect on the QTc interval when clobutinol is co-administered with other medicinal products that share this property. The official regulatory structure restricts co-administration with substances categorized as QTc-prolonging medicinal products (e.g., certain Antiarrhythmics, Macrolide antibiotics, and Antipsychotics), classifying this combination as a prohibited or contraindicated combination.

Interaction Type Official Regulatory Statement
Pharmacodynamic Additive QTc prolongation and heightened risk of ventricular arrhythmia.
Pharmacokinetic Exposure may increase due to metabolic inhibition, which exacerbates QTc risk.

Regulatory documentation also notes that the severity of the central pharmacodynamic interaction can be increased in certain patient populations. The official profile identifies patients with conditions such as Hypokalaemia, Hypomagnesaemia, or Structural Heart Disease as having a heightened susceptibility to the interaction, requiring strict adherence to the avoidance constraint.

Timing-based administration rules are not documented; the systemic nature of the risk requires avoidance of combination rather than temporal separation.

Mechanism of Action

Dual-Action Modulation of the Central Cough Center

Silomat's primary mechanism involves activating the Sigma-1 (sigma1) receptor located in the brainstem's cough center, which directly modulates the activity of the central cough reflex. This central action elevates the cough threshold and interferes with the afferent signaling within the neural circuit .


Peripheral Modulation and Sensory Signal Reduction

In addition to its central effect, the drug exerts peripheral actions by inhibiting Voltage-gated Sodium ( Na^+) channels and acting as an antagonist at Muscarinic Acetylcholine Receptors. These activities result in a reduced excitability of peripheral sensory nerve endings and decreased glandular secretions, modulating afferent signal strength.


Elevation of the Cough Threshold through Mechanistic Synergy

The drug’s overall physiological consequence arises from the convergence of these two distinct mechanistic domains: the central modulation and the peripheral signal modulation. The simultaneous action of reducing peripheral excitability and decreasing central response results in an overall elevation of the cough threshold, which is the core physiological adjustment produced by the mechanism.

Dosage and Administration Information

The information below reflects the former authorized parameters for clobutinol (Silomat) usage prior to the recommendation for the suspension and revocation of marketing authorizations in major global regions. This summary outlines the administration principles formerly defined for the medication.


Instruction Map: How to use Silomat — Official Administration Guidelines

Administration Scope

Entity Description (Based on Former Parameters)
Route of administration Formerly authorized for oral intake (as drops, syrup, or coated tablets) and, in some contexts, for intramuscular or intravenous administration via injection solutions.
Dosing schedule The standard maximum approved daily dose was 240 mg of clobutinol, based on a single dose not exceeding 80 mg.
Age-group rules Regional labeling previously stipulated that use was not recommended in children under two years of age.
Special conditions The authorized administration was intended only for short-term symptomatic use corresponding to acute episodes.

Instruction Classifications (High-Level)

Classification Description (Based on Former Parameters)
Administration method Oral and Parenteral (IM/IV).
Frequency pattern The maximum authorized dose was typically administered on a three times a day (t.i.d.) schedule.
Regulatory basis The current status is defined by the recommendation for revocation of Marketing Authorisations.
Use-context constraints Use was restricted to a limited, acute duration.

Resulting Procedural Structure (Former Use Pattern)

Official step sequence (Former Use Pattern):

  • Administration involved selecting one of the authorized dosage forms for oral or injection routes.
  • Dosing followed a set schedule of up to 80 mg per intake, taken three times daily.
  • The overall protocol restricted administration to a short-term duration suitable for acute symptoms.

Connection to the overall use protocol:

The official use protocol defined administration by specifying the available oral and injectable routes alongside a clear maximum dose and a t.i.d. frequency. This structure framed the former administration as a dose-limited, acute intervention, with specific rules previously applied to restrict use in certain pediatric populations.

Recent Clinical Evidence

Silomat: Recent Clinical Evidence / Overview of Studies

Efficacy Evaluation

Research explores the use of Silomat, which contains the active substance pentoxyverine (or oxeladin in some formulations), for managing a non-productive, or dry, cough. Studies primarily focus on its mechanism of affecting the central cough center in the brain. Unlike opioid-based cough suppressants, research suggests pentoxyverine works through a different pathway, potentially involving antagonism at muscarinic receptors ( M1) and agonism at sigma (sigma 1) receptors.

Clinical trials have evaluated the investigational treatment against placebo controls and sometimes other antitussive agents. Outcomes assessed in these trials include the frequency and severity of coughing over short durations, typically five days. Both pentoxyverine and other antitussive agents were associated with statistically significant improvements in cough parameters in randomized comparative studies.

Safety and Tolerability Profile

The safety and tolerability of pentoxyverine have been assessed across various formulations, including syrups and drops. Common adverse events reported in trials generally include mild, temporary effects such as nausea, vomiting, diarrhea, dry mouth, and headache.

Research protocols for clinical assessment may include specific exclusion criteria, such as a history of bronchial asthma, severe respiratory insufficiency, or certain types of glaucoma. Caution is generally advised regarding the concomitant use of central nervous system depressants, as this combination may be associated with increased sedation.

Key Studies & References

  1. Randomized, placebo-controlled clinical trial assessing the efficacy of pentoxyverine in patients with acute dry cough

Frequently Asked Questions (FAQ)

Common questions about Silomat (FAQ)

Q: What is Silomat and what is it used for?

A: Silomat is a medication containing clobutinol, which belongs to a class of medicines called cough suppressants (antitussives). It works centrally in the brain to reduce the cough reflex.

It is used for the symptomatic treatment of dry, unproductive cough in adults and children.


Q: How should I take Silomat?

A: Silomat is typically available as oral drops or capsules, and the specific instructions depend on the formulation and the user's age.

  • Oral drops: The drops are usually taken several times a day.
  • Capsules: Capsules are typically taken 3 times a day.

It should be taken exactly as prescribed by your doctor or as indicated in the patient leaflet. Do not exceed the recommended dose.


Q: What should I do if I miss a dose?

A: If you miss a dose of Silomat, take it as soon as you remember, unless it is almost time for your next scheduled dose. In that case, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one.


Q: What are the common side effects of Silomat?

A: Common side effects of Silomat may include:

  • Drowsiness or fatigue
  • Mild gastrointestinal issues (e.g., nausea, stomach discomfort)
  • Dizziness

If these effects are persistent or severe, you should consult your doctor or pharmacist. A full list of possible side effects is provided in the patient information leaflet.


Q: Can Silomat be used with other medications?

A: It is important to inform your doctor or pharmacist about all other medications you are taking, including over-the-counter medicines, herbal remedies, and supplements.

Combining Silomat with other central nervous system depressants (like alcohol or sedatives) may increase the risk of drowsiness. Your healthcare provider will determine if it is safe to take Silomat with your current medications.

How should Silomat be stored and disposed of?

The official requirements for storing and disposing of Silomat (Clobutinol hydrochloride) are standardized to maintain stability and ensure safety, as mandated by regulatory authorities.


Storage Conditions and Handling

  • Temperature: Store the medication at Controlled Room Temperature, typically 20 C to 25 C (68 F to 77 F).
  • Protection: The product must be protected from light and excessive moisture. Liquid forms (syrups/drops) must not be frozen as this compromises the formulation.
  • Container: Keep the container tightly sealed and observe the expiration date printed on the packaging.
  • Child Safety: All products must be stored out of the sight and reach of children.

Disposal Instructions

Expired or unused Silomat should be disposed of through an authorized drug take-back program or permanent collection site. To prevent environmental contamination, the medicine must not be flushed down the toilet or poured into a drain unless specifically instructed by a regulatory authority.

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

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