Sm-33

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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 Sm-33

What is Sm-33? The Oromucosal Relief Preparation

Sm-33 is a multicomponent stomatological preparation (a medicine for the oral cavity and gums) designed for topical application to the mouth lining.

Property Description
Active ingredients Lidocaine, Levomenthol, Salicylic Acid, Tannic Acid, Thymol
Form Viscous Gel or Solution
Pharmacological class Local Anesthetic, Analgesic, Antiseptic, Astringent
Common purpose Rapid, localized relief from oral discomfort
Origin Combination (Synthetic and Derived)

What Type of Medicine is Sm-33?

Sm-33 is classified as an oral relief product, combining the actions of a local anesthetic, an analgesic, and an antiseptic/astringent agent. This combination of functions means it is designed to manage localized discomfort, soothe irritation, and provide gentle cleansing to the affected oral lining. The medicine is prepared as a viscous gel or solution specifically for oromucosal application. It is clinically recognized for its targeted use in managing surface pain and inflammation in the oral cavity.

Sm-33 Active Ingredients and Combination Formula

The core of Sm-33 is a combination product that blends several therapeutic ingredients rather than relying on a single compound. The primary pain-relieving ingredient is Lidocaine, a well-established amide-type compound used to produce temporary local numbness. The formulation is distinctively blended with Levomenthol (a cooling counter-irritant) and mild astringent/antiseptic agents such as Salicylic Acid, Tannic Acid, and Thymol. Components like Tannic Acid are known for their astringent effect, which helps to protect superficial tissues by forming a protective layer over the affected area. The final preparation utilizes an Alcohol-Glycerol base, blending both synthetic and naturally derived components.

The General Purpose of Sm-33 Relief

The general purpose of Sm-33 is to provide rapid, localized soothing and anesthetic relief to areas of discomfort in the mouth. The formulation delivers an immediate numbing sensation from the Lidocaine, supported by the cooling and calming effect of Menthol. This dual action is crucial for quickly managing acute, localized soreness, such as discomfort associated with minor oral abrasions or gum irritation. The multi-action formula allows the user to experience fast temporary relief from irritation and pain on the oral lining.

What side effects are possible with Sm-33?

Possible Side Effects and Safety Information

Official safety documentation for topical oral anesthetics, such as those that may be contained in products like Sm-33 (including benzocaine), outlines a specific set of adverse reactions and safety restrictions.

Serious and Clinically Significant Adverse Reactions

The most serious systemic risk is methemoglobinemia, a rare but potentially fatal blood disorder that reduces the oxygen-carrying capacity of the blood. Symptoms can include pale, grey, or blue-colored skin, lips, and nail beds, as well as shortness of breath, confusion, and a rapid heart rate. These symptoms may appear within minutes to one or two hours after application and can occur after the first use or subsequent uses.

Other serious effects, particularly associated with elevated systemic absorption, include Central Nervous System (CNS) toxicity, which may manifest as seizures, lightheadedness, or confusion, and cardiovascular effects, such as heart rhythm disturbances.

Safety Restrictions and Vulnerable Populations

Regulatory authorities have issued strong warnings and contraindications against the use of oral topical products containing benzocaine in infants and children younger than 2 years of age, due to the heightened risk of methemoglobinemia in this population.

General safety considerations documented in labeling include:

  • Dose/Exposure Limitations: Risk is increased with the use of large quantities, application over large areas of the body, or application to broken, raw, or blistered skin, all of which increase systemic absorption.
  • Hypersensitivity: The product is generally contraindicated in individuals with known severe allergic reactions to ester-type local anesthetics.
  • High-Risk Patients: Patients with pre-existing breathing problems (e.g., asthma, bronchitis), heart disease, or certain hereditary conditions may be at greater risk for complications related to methemoglobinemia.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdose with this topical preparation occurs following accidental or intentional ingestion of a significant quantity, leading to systemic toxicity primarily from the active ingredients, Salicylic Acid and Lidocaine. The official regulatory classification for this event is high-risk, potentially resulting in severe, life-threatening complications.

Documented Overdose Presentations

System Documented Symptoms / Manifestations
Central Nervous System (CNS) Tinnitus (ringing in ears), Confusion, Lethargy, Seizures, Dizziness, Metallic taste, Paresthesia.
Cardiovascular / Respiratory Arrhythmias, Hypotension, Hyperventilation, Respiratory depression, Cardiac arrest
Metabolic Fever (Hyperthermia), Metabolic acidosis, Methemoglobinemia

When Immediate Medical Help is Required

Official regulatory instructions mandate that you seek immediate medical attention for any suspected overdose or large accidental ingestion, regardless of the presence of severe symptoms. Referral to an Emergency Department is required for symptomatic patients or in cases involving children or high ingestion volumes.

Severe or Life-Threatening Outcomes: Documented severe outcomes include seizures, respiratory failure, metabolic acidosis, and cardiovascular collapse. Delay in seeking help for these conditions may lead to death.

Overdose Management: Hospital management protocols, as described in official documents, often include supportive measures such as the administration of activated charcoal, monitoring of serum salicylate levels and blood gases, and interventions like urine alkalinization or hemodialysis for severe toxicity. No specific antidote is known for general salicylate poisoning, but treatments like Intravenous Lipid Emulsion are cited for severe Lidocaine toxicity.

Therapeutic Uses of Sm-33

What Sm-33 Treats: Main Uses and Benefits

The primary role of Sm-33 is to provide supportive symptomatic relief across a range of minor, localized oral irritations and lesions. It is commonly used when short-term symptomatic assistance is needed to ease discomfort that interferes with daily functioning.


This preparation is generally applied across domains where additional symptomatic support is needed in situations where symptoms cluster into patterns of localized irritation and soreness. It is used across conditions presenting with acute episodes, including transient mouth ulcers, minor oral abrasions, localized gingivitis, and pain from dental appliances such as new dentures or braces.

The medication helps address symptom clusters that may become intense or disruptive. It is applied in contexts marked by increased discomfort or tension, and provides symptomatic relief that helps patients cope more steadily with these difficult episodes. This therapeutic support contributes to easing the overall symptom load, contributes to improved comfort during periods of heightened symptoms.

Quick Fact: Symptom Management for Oral Discomfort

Sm-33 is commonly used when symptoms become more noticeable due to mechanical factors (like friction from dental devices) or localized inflammatory states, providing supportive relief when symptoms interfere with routine activities.

Eligibility and Restrictions for Use

Who Can and Cannot Use Sm-33?

The official eligibility profile for Sm-33, a topical oral preparation, is strictly defined by regulatory authorities based on age and underlying conditions related to its active components (Salicylic Acid and Lidocaine).


Contraindicated Populations

Use of this medicine is absolutely contraindicated in the following groups:

  • Children and Adolescents Younger than 16 years of age (due to the salicylate content and the theoretical risk of Reye's syndrome).
  • Individuals with known hypersensitivity or allergy to any active ingredient (Lidocaine, Salicylic Acid, etc.).
  • Patients with a known allergy to Acetylsalicylic Acid (Aspirin) or other NSAIDs.
  • Pregnant patients in the third trimester.

Eligible Population and Restrictions

Population Group Regulatory Status
Eligible Age Group Adults and Adolescents aged 16 years and older.
Pregnancy Contraindicated in the third trimester; conditional use in the first two trimesters requires consultation.
Breastfeeding Generally acceptable for short-term topical use.
Underlying Conditions Use requires caution in patients with severe hepatic (liver) impairment or active peptic ulceration (formally contraindicated in similar products).

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory information for Sm-33 focuses on potential systemic interactions arising from the Lidocaine and Salicylic Acid components, should absorption exceed minimal levels. These interactions are classified into pharmacokinetic and pharmacodynamic categories based on government drug labels.

Interaction Scope

Category Documented Interaction Statement
Metabolic Interactions Co-administration with strong inhibitors of CYP1A2 and CYP3A4 (e.g., Cimetidine, Fluconazole) may reduce the clearance of Lidocaine, potentially leading to increased plasma concentrations.
Pharmacodynamic Interactions Use with other amide-type local anesthetics or Class III antiarrhythmics (e.g., Amiodarone) may cause additive systemic effects on the heart or central nervous system.
Additive Exposure Risk The Salicylic Acid component may contribute to the total body load when co-administered with other salicylate-containing analgesic products.

Interaction-Related Restrictions

Regulatory documents include a procedural restriction for topical anesthetics. To avoid the risk of impaired swallowing or biting trauma due to temporary numbness, a separation of 60 minutes between product application and the ingestion of food or chewing gum is required. The risk of systemic interaction is also officially noted as heightened in patients with severe hepatic dysfunction due to reduced clearance of Lidocaine.

Mechanism of Action

Peripheral Nerve Impulse Blockade

This core mechanism involves the active ingredient Lidocaine, which directly engages and blocks voltage-gated sodium channels (Nav) on sensory neurons. By halting the flow of sodium ions, the signal transmission pathway is interrupted at the application site, resulting in the establishment of a state of local nerve conduction block in the targeted area.


Sensory Channel Modulation

The component Levomenthol modulates the somatosensory system by acting as an agonist for the TRPM8 channel, a specialized cold receptor. Activation of this pathway generates a competing cold-sensory signal that modulates the perception of the existing somatosensory input, contributing to the physiological effect of sensory distraction.


Superficial Tissue & Pathway Modulation

The formula engages structural and biochemical pathways. Tannic Acid causes protein coagulation on the mucosal surface, physically stabilizing the tissue surface structure through the formation of a superficial protein layer. Concurrently, Salicylic Acid provides mild, localized attenuation of inflammatory responses through the inhibition of COX enzymes, which promotes the structural modulation of the tissue surface and attenuates the chemical sensitization of peripheral nociceptors.

Dosage and Administration Information

Official Administration Guidelines

Sm-33 is officially designated for topical, oromucosal administration, meaning the product must be applied directly and locally to the lining of the mouth. It is supplied as both a viscous gel and a liquid/paint formulation, with the underlying usage principles being consistent across both forms.

The official instructions define a qualitative dosing approach. Users are directed to apply the product only to the affected area of the oral mucosa, rather than measuring a specific volumetric amount. For the liquid form, a clean applicator must be used to ensure the preparation is applied thoroughly to the localized site.

Frequency and Duration

The standard schedule requires that application be administered at fixed intervals of every three hours (q3h) as needed for localized relief. This frequency establishes the primary, time-based control mechanism for managing total application.

The instructions define usage as being for temporary relief only. Users must avoid prolonged treatment and are directed to discontinue use and seek further action if the condition persists despite adherence to the application schedule.

Procedural and Population Rules

Application is made directly from the container; no dilution or prior mixing is required. While noted for use in the general population, the gel formulation is also officially noted for use in children and teenagers.

After each use, the container's cap must be replaced and sealed tightly as a required handling procedure. This entire official protocol establishes a localized, short-term usage pattern controlled strictly by the fixed three-hour interval and the mandatory instruction to cease use if symptoms continue beyond the temporary period.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Sm-33


Evidence for Temporary Relief of Localized Oral Pain

Research concerning the use of Sm-33, or similar multi-component preparations, has primarily utilized Randomized Controlled Trials (RCTs) and systematic reviews to examine whether temporary symptomatic change occurs over time related to discomfort in the oral lining. The studies were relevant in research contexts involving localized oral lesions. Researchers in these contexts monitored outcomes related to physical discomfort, tracking measurements on scales such as the Visual Analog Scale. These investigations also explored assessments related to oral fluid intake in observed populations that included adults and older children.

Studies reported measurements where patterns of symptomatic evolution were observed during the immediate period following application, often within the first hour. Research highlights changes measured during the study period, which included instances of temporary symptomatic evolution in some reports. However, the evidence quality varies across studies, and some regulatory analyses noted that the data often involved varied formulations. The research suggests that the follow-up durations were limited, focusing strictly on short-term or episodic symptom patterns.


Research on Discomfort from Dental Appliances

Research examining the use of this preparation for managing discomfort associated with dental appliances, such as new braces or dentures, mostly was observed in observational settings and recorded through Post-Marketing Data. Research explored patient-reported outcomes describing perceived discomfort, focusing on comfort levels and the subjective ease of use. The certainty remains low for this indication when compared to formal, large-scale RCTs, as the evidence is predominantly non-randomized. The findings are based on modest sample sizes, and comparative evidence is lacking.


Documented Research Gaps and Uncertainties

The evidence highlights what is known—and what is still uncertain—about this preparation. Key limitations include the fact that the sample sizes were modest in many older or observational reports, and the evidence quality varies across studies depending on the indication. The overall research is dominated by a focus on short-term relief, and limited information exists for long-term outcomes, meaning that the full picture of long-term effects are not fully established.

Key Studies & References

  1. Clinical Efficacy of a Topical Gel for the Treatment of Minor Oral Ulcers: A Triple-Blind Randomized Controlled Trial
  2. Astringency Sensitivity to Tannic Acid: Effect of Ageing and Saliva
  3. Oral lidocaine containing products and risks of toxicity in younger children and infants - Medicines Adverse Reactions Committee (Regulatory Review)

Frequently Asked Questions (FAQ)

Common questions about Sm-33 (FAQ)


Q: What types of medications or supplements are known to interact with Sm-33?

Official regulatory information focuses on documented drug-drug interactions. These potential interactions include medicines that are amide-type local anesthetics, certain heart rhythm medicines (Class III antiarrhythmics), and other salicylate-containing pain products. Regulatory documents mention the potential for interaction between the Lidocaine component and strong inhibitors of liver enzymes (like CYP1A2 and CYP3A4) which affect how the body processes the medicine.


Q: Does Sm-33 contain any ingredients that might trigger a common allergy?

According to the official product information, Sm-33 is contraindicated (should not be used) if you have a known hypersensitivity or allergy to any of its active components. This includes known allergies to Aspirin (Acetylsalicylic Acid) or other non-steroidal anti-inflammatory drugs (NSAIDs). Patient information typically includes a complete list of ingredients for individual review if known allergies are a concern.


Q: Is it normal if I feel drowsy or dizzy after using Sm-33?

Feeling lightheaded or confused is not described as a normal effect of use. Official warnings indicate that signs of Central Nervous System (CNS) toxicity, which can include confusion or lightheadedness, are a possible serious effect. The documentation links this serious risk to circumstances that increase systemic absorption, such as applying excessive product or covering large areas.


Q: Can older adults use Sm-33 without any special precautions?

According to official guidelines, use requires caution in patients with certain pre-existing conditions. Specifically, the risk is heightened for patients with severe hepatic (liver) impairment because this can reduce the body's ability to clear the Lidocaine component. If an older adult has existing liver impairment, regulatory information suggests the condition warrants review by a health professional.


Q: What is the definition of 'contraindication' as it relates to Sm-33?

In official medical documents, a contraindication is a specific condition or circumstance that makes the use of a medicine potentially harmful, and therefore its use is absolutely prohibited. For Sm-33, conditions like pregnancy in the third trimester or having an allergy to Aspirin are examples of conditions that regulatory bodies deem contraindications.


Q: Does Sm-33 interact with common pain relievers like ibuprofen or acetaminophen?

Official warnings note that the Salicylic Acid component may create an additive exposure risk if used alongside other salicylate-containing analgesic products. Furthermore, official information indicates that a known allergy to other non-steroidal anti-inflammatory drugs (NSAIDs), a group that includes ibuprofen, may be a contraindication for Sm-33.


Q: Can I use Sm-33 if I have an existing kidney or liver condition?

Regulatory documents state that use requires caution in patients with severe hepatic (liver) impairment, as this can affect how the body breaks down the Lidocaine component. Kidney conditions are not listed as a primary contraindication. For patients with an existing organ condition, regulatory documents imply that a review of their full medical history by a health professional is relevant prior to use.


Q: If Sm-33 is stored incorrectly, does it lose its effectiveness?

Sm-33 has specific official storage requirements, such as storing it Below 30°C and ensuring the cap is replaced and sealed tightly after each use. These rules are put in place to maintain the product's integrity and stability throughout its shelf life. Incorrect storage is noted as having the potential to compromise the product's integrity and stability.


Q: What is the maximum duration of treatment with Sm-33 as described in official guidelines?

The official guidelines emphasize that Sm-33 is intended for temporary relief of localized discomfort. There is no specific number of days listed as a maximum duration, but users are directed to avoid prolonged treatment. The official instructions indicate that if the condition continues or persists after use, the user is directed to discontinue the product and seek further medical action.


Q: Is Sm-33 available over-the-counter or do I need a prescription?

Regulatory status varies by region, but in some areas, Sm-33 is classified as a Pharmacy Medicine. This means the product can be purchased without a prescription, but the sale often requires it to be obtained directly from a pharmacy after consultation with a pharmacist.


Q: Are there any warnings about driving or operating machinery while using Sm-33?

Regulatory warnings are issued due to the documented potential for Central Nervous System (CNS) toxicity when systemic absorption is elevated. Because this can include side effects such as confusion or lightheadedness, warnings for similar CNS-affecting drugs often advise caution when engaging in tasks like driving or operating machinery after use.


Q: What should I do if the side effects of Sm-33 get worse?

The official instructions provide clear guidance: if your symptoms or condition should persist or worsen, the required course of action is to discontinue the product. The official instructions state that the next required step is to seek medical advice from a healthcare professional for further evaluation.

How should Sm-33 be stored and disposed of?

Official Storage and Disposal Requirements

Storage of SM-33 Gel must strictly comply with regulatory labeling to ensure product integrity and stability. The required storage conditions are defined by both temperature control and container integrity rules.

Condition Regulatory Requirement
Temperature Store Below 30°C (86°F).
Container Sealing The cap must be replaced and sealed tightly after each use.
Initial Integrity Do not use if foil cap seal is broken.
Shelf Life Stability is maintained for 3 years under the required storage conditions.

For disposal, official instructions require that unused or expired product be discarded according to local regulations for pharmaceutical waste. This ensures responsible and safe handling of the product upon its removal.

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

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