Termisil

Quick links to important sections

Termisil

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 Termisil

Property Description
Active Ingredient Terbinafine Hydrochloride
Primary Forms Tablets, Cream, Solution, Gel
Pharmacological Class Antifungal Agent, Allylamine derivative
General Purpose To eliminate fungal pathogens (Mycoses)
Origin Synthetic agent

What Type of Medicine is Termisil?

Termisil is a single-ingredient medicinal product whose active agent is Terbinafine Hydrochloride, classified as an Antifungal Agent. This compound belongs to the allylamine derivative chemical group, which is a synthetic agent specifically designed to fight infections caused by various fungal pathogens, broadly known as mycoses. The fundamental purpose of this drug class is to successfully resolve these infections. Terbinafine is clinically recognized as a potent agent, commonly used as a cornerstone treatment for fungal skin conditions, such as general tinea infections.

Composition and Available Formulations

The core therapeutic component of Termisil is the active ingredient, Terbinafine Hydrochloride. This compound is presented in multiple dosage forms to match the type and location of the infection. The primary forms include tablets, intended for oral (systemic) use to treat internal or widespread conditions, and localized preparations like cream, solution, or gel for dermal (topical) use on the skin. Termisil often positions its topical forms for over-the-counter (OTC) access, whereas the systemic tablets typically require a prescription. The formulation combines the active Terbinafine Hydrochloride with various excipients, ranging from inert tablet excipients for oral consumption to lipophilic bases for topical application.

How Does Terbinafine Exert Its General Effect?

Terbinafine is primarily known for its fungicidal activity, meaning its general purpose is the definitive destruction of the fungal organism, rather than simply slowing down its growth (fungistatic action). This potent outcome stems from a highly specific interference where the drug blocks the squalene epoxidase enzyme. Inhibition of this enzyme is a mechanism that prevents the fungus from producing ergosterol, a molecule vital for building its cell wall and protective structure. This specific disruption in the fungal cell's integrity provides a robust method for eliminating the pathogen.

Regulatory References

  1. NIH, StatPearls

What side effects are possible with Termisil?

Possible Side Effects and Safety Information

Termisil (Terbinafine) can cause a range of adverse reactions, some of which are serious and require immediate medical attention. The most common reported side effects include headache, gastrointestinal symptoms (such as nausea, diarrhea, dyspepsia, and abdominal pain), skin rash, itching (pruritus), and abnormal liver enzyme tests.

Serious Adverse Reactions and Safety Concerns

Official regulatory documents highlight the risk of several serious adverse reactions:

  • Hepatotoxicity: Cases of severe liver injury, including liver failure (some leading to transplant or death), have occurred in patients with and without pre-existing liver disease. Termisil is generally not recommended for patients with active or chronic liver disease.
  • Sensory Disturbances: Changes in taste (dysgeusia, including loss of taste or ageusia) and smell (anosmia) have been reported. These changes can be severe, potentially leading to decreased appetite, weight loss, and depressive symptoms, and may be prolonged or permanent.
  • Serious Skin Reactions: Rare, life-threatening skin reactions, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), as well as Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome, have been documented.
  • Hematologic Effects: Severe neutropenia (a low white blood cell count) has been reported.

Safety Restrictions and Monitoring

Patients are advised to undergo serum transaminase testing (liver enzyme check) prior to starting therapy. Treatment must be discontinued if there is clinical or biochemical evidence of liver injury (e.g., persistent nausea, jaundice, dark urine), a progressive skin rash develops, or if taste or smell disturbances occur. The drug is contraindicated in individuals with known hypersensitivity to terbinafine.

Overdose and Emergency Response

Overdose: When to Seek Immediate Medical Help

The following information on overdosage with Termisil (terbinafine) is based strictly on the content of official governmental regulatory documents from agencies such as the FDA, EMA, and Health Canada.

Overdose Symptoms and Manifestations

Symptoms reported in cases of overdosage, typically following ingestions up to 5 grams of the drug, primarily involve the gastrointestinal and central nervous systems. Documented presentations include:

  • Gastrointestinal: Nausea, vomiting, and abdominal or epigastric pain.
  • Central Nervous System: Headache and dizziness.

Required Emergency Actions

In the event of a suspected or confirmed overdose, the regulatory labeling emphasizes the need for immediate professional intervention. Patients should be taken to a hospital or medical facility promptly. Management of an overdose is primarily supportive and symptomatic.

  • Immediate Procedure: The recommended treatment procedure involves eliminating the drug from the body, chiefly through the administration of activated charcoal.
  • Supportive Care: Subsequent management focuses on providing symptomatic and supportive treatment as required by the patient's clinical state.

When Immediate Medical Help is Required

Contact emergency medical services or a poison control center immediately if an overdose is suspected or confirmed, even if no symptoms are yet apparent. This is necessary to initiate prompt care and guide the necessary steps for drug elimination and stabilization.

Therapeutic Uses of Termisil

Termisil is an antifungal agent aligned with the elimination of pathogens that cause mycoses, offering supportive relief for distinct symptomatic domains across the body. The medication is used in conditions presenting with systemic or localized discomfort and may assist with managing symptoms associated with acute or episodic changes.

Targeting Common Fungal Skin Infections (Tinea)

This domain covers common and localized fungal infections such as Tinea Pedis (Athlete's Foot), Tinea Cruris (Jock Itch), and Tinea Corporis (Ringworm). The treatment helps address groups of symptoms that create noticeable interference with daily stability, leading to easing the manifestations of itching, scaling, redness, and peeling, thereby contributing to improved day-to-day comfort.

Treating Deep-Seated Nail and Hair Mycoses

Termisil is relevant in clinical settings marked by the heightened distress of Onychomycosis (fungal nail infection) and Tinea Capitis (scalp ringworm). It provides support needed to eliminate the infection source and assists with slowing the progression of damage, which supports the process of healthy nail outgrowth and the clearing of hair and scalp lesions.


Quick Fact: Relief for Persistent Fungal Symptoms
Termisil is applied in addressing situations where symptoms, such as nail discoloration and inflammation, have manifested in deep keratinized tissue, where it assists with maintaining functional stability and supports the process of healthy tissue restoration.

Regulatory References

  1. NIH MedlinePlus overview

Eligibility and Restrictions for Use

Official Eligibility and Contraindications for Termisil

The eligibility for systemic use of Termisil (oral Terbinafine) is strictly defined by regulatory authorities based on organ function, age, and hypersensitivity status. The medicine is primarily intended for use in adults (18 years and older) for approved fungal infections.

Who Must Not Use Termisil (Contraindications)

Termisil is absolutely contraindicated and must not be used by patients with:

  • Chronic or Active Liver Disease (Hepatic Contraindication).
  • A history of allergic reaction or hypersensitivity to Terbinafine or any component of the formulation.

Populations Requiring Restriction or Caution

Use is not recommended in several populations due to limited study data or potential risk, including:

  • Patients with Impaired Renal Function (Creatinine Clearance <50 mL/min).
  • Mothers who are breastfeeding, as the drug is excreted into breast milk.
  • Pregnant individuals unless the clinical necessity for treatment is judged to outweigh potential risks.

Oral tablet use is generally not recommended for children and adolescents below 18 years of age. Caution is also required for patients with pre-existing conditions such as Lupus Erythematosus or Psoriasis, as the drug has been reported to cause exacerbation.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Termisil's oral form has a defined interaction profile based on its effect on the cytochrome P450 (CYP) enzyme system, which is documented in official regulatory labeling.

Pharmacokinetic Interactions (Exposure Modification)

Termisil is a potent inhibitor of the CYP450 2D6 isozyme, which is the basis for several documented interactions. This inhibition may reduce the clearance of co-administered medicines that are metabolized primarily by CYP2D6, such as tricyclic antidepressants, certain beta-blockers, and SSRIs. For example, co-administration with Desipramine has been shown to decrease its clearance by 82%.

Conversely, other medicinal products can alter Termisil's own systemic exposure:

  • Increased Termisil Exposure: Co-administration with enzyme inhibitors like Fluconazole or Cimetidine is documented to significantly raise Termisil's plasma levels. Fluconazole, for instance, increased Termisil AUC by 69%.
  • Decreased Termisil Exposure: Enzyme inducers, such as Rifampicin, can reduce Termisil exposure by increasing its clearance by 100%.

Pharmacodynamic and Other Constraints

  • Warfarin: Regulatory information reports rare cases of changes in the International Normalized Ratio (INR) and prothrombin time when Termisil is co-administered with this anticoagulant.
  • Oral Contraceptives: Menstrual disturbances, including breakthrough bleeding and irregular cycles, have been reported with concomitant use of Termisil tablets.
  • Population Restriction: The use of Termisil oral tablets is contraindicated in patients with chronic or active liver disease, as stated in prescribing information.

Mechanism of Action

Inhibition of Fungal Enzyme Activity

The active ingredient, terbinafine, acts by inhibiting a key enzyme within the fungal sterol biosynthesis pathway. Termisil engages mechanisms within the fungal cell that involve enzyme-mediated signaling. Specifically, it functions as a non-competitive inhibitor of the enzyme squalene epoxidase (also known as squalene monooxygenase). This enzyme catalyzes an essential molecular step in the fungal-specific pathway for synthesizing ergosterol, a structural component of the fungal cell membrane.


Disruption of Cell Membrane Integrity

The inhibition results in a mechanistic cascade characterized by two primary biochemical effects. First, blocking squalene epoxidase prevents the formation of ergosterol, causing a deficiency and structural instability in the fungal plasma membrane. Second, this action results in the accumulation of the precursor metabolite squalene to elevated levels within the fungal cell. The combined intracellular effects lead to plasma membrane disruption and the subsequent loss of fungal cellular integrity, concluding the mechanistic cascade.

Dosage and Administration Information

How to Use Termisil: Administration Guidelines

Termisil (Terbinafine Hydrochloride) is administered through distinct routes and schedules according to the infection being addressed, based strictly on prescribing information. The oral route uses tablets or granules for systemic treatment, while topical forms like the 1% cream are applied locally to the skin.


Administration and Dosing Principles

The standard oral dose for adults is 250 mg taken once daily. The treatment duration is fixed based on the infection site: six continuous weeks for fingernail onychomycosis and twelve continuous weeks for toenail onychomycosis. If a dose is missed, it should be taken as soon as remembered, unless it is less than four hours before the next scheduled dose, in which case the missed dose must be skipped.

Oral tablets may be taken with or without food. However, the oral granules, which are used for weight-based pediatric dosing, must be sprinkled onto a spoonful of soft, non-acidic food, such as mashed potatoes, and must be swallowed immediately without chewing.


Topical Application and Special Constraints

Topical preparations, such as the 1% cream, are generally applied once or twice daily to the thoroughly cleansed and dried affected skin area. The duration of topical treatment typically ranges from one to four weeks. Users are restricted from applying an occlusive dressing (airtight cover) over the treated area unless specifically advised by a healthcare professional.

Oral use is generally not recommended in patients with significantly reduced renal function (creatinine clearance le 50 mL/min), a constraint that governs the initiation of systemic therapy.

Recent Clinical Evidence

Termisil: Recent Clinical Evidence

Overview of Clinical Research

Research on this therapeutic option primarily consists of randomized, double-blind, placebo-controlled trials, which is considered the standard for evaluating treatments. The majority of studies have focused on evaluating changes in symptoms of acute migraines following administration of the treatment.


Efficacy Findings

  • Acute Symptom Change: Clinical trials have reported on the measured difference in pain levels within two hours following a single dose for a specific percentage of participants. The most frequently measured endpoints include freedom from headache and relief from associated symptoms (e.g., light sensitivity, sound sensitivity) at the two-hour mark.
  • Long-term Use: Long-term data has been evaluated, suggesting that the treatment resulted in an adverse event rate comparable to placebo and measurements indicated changes in symptom frequency for chronic use. The studies examined changes in overall symptom frequency and disability scores over six months.
  • Comparative Effects: In a comparative trial, the medication demonstrated different measurements than a placebo across primary endpoints. Another study assessed the effect relative to an active comparator, reporting similar outcomes for both treatments at four hours.
  • Combination Treatment: Studies have explored whether the combination with anti-nausea medication yields different outcomes for participants reporting nausea/vomiting as a prominent symptom. Outcomes suggested that the combination resulted in a statistically different rate of sustained pain freedom compared to the drug alone in this subset of participants.

Administration and Timing

Studies have generally administered the medication at the first sign of a migraine to evaluate its effect. The research examined whether the drug influenced the speed of symptom change. Follow-up research has explored whether outcomes change when administration is delayed beyond the onset of moderate pain. Results indicated a trend toward different measured outcomes when administration occurred earlier.


Conclusion of Evidence

While research is ongoing, this treatment has been studied in several recent trials. Evidence has primarily focused on the evaluation of acute migraine treatment and general study participation over short- and mid-term durations. Research continues to explore its potential application in other headache types.

Frequently Asked Questions (FAQ)

Common questions about Termisil (FAQ)


Q: What specific types of fungal infections does Termisil treat?

The oral tablet form of Termisil is approved for the treatment of fungal infections in the nails (onychomycosis) of the toenails and fingernails. Other available forms of Termisil, such as topical creams or gels, are approved for superficial skin infections like ringworm (tinea corporis), jock itch (tinea cruris), and athlete's foot (tinea pedis).


Q: Is Termisil available in different forms, like a tablet, cream, or spray?

Yes, Termisil is available in several formulations. The active ingredient, terbinafine, is available in prescription forms (tablets and granules) for systemic use and in over-the-counter topical forms, including creams, gels, solutions, and sprays.


Q: What is the difference between Termisil and the generic version (terbinafine)?

The brand-name product (Termisil/Lamisil) and its generic equivalent (terbinafine) contain the exact same active ingredient. Regulatory standards require generic products to meet the same quality, strength, purity, and stability requirements as the brand-name drug.


Q: Can Termisil be used to treat fungal infections in the scalp (tinea capitis)?

Yes, the oral forms of Termisil (tablets and granules) are indicated by official regulatory bodies for the treatment of tinea capitis (fungal infection of the scalp), particularly in certain pediatric populations (children 4 years of age and older).


Q: Can Termisil interact with herbal supplements or dietary products?

Termisil affects certain liver enzymes (CYP2D6) used to process many substances. Official product information suggests a review of all co-administered products, including herbal remedies, supplements, and over-the-counter medicines, as they may alter the drug's concentration in the blood or vice versa.


Q: What is the typical length of treatment for a toenail fungal infection with Termisil?

According to official administration guidelines, the standard treatment duration for fungal infections of the toenail (onychomycosis) is 12 continuous weeks of once-daily oral tablet use.


Q: What should be done if a dose of Termisil is missed?

Regulatory guidelines detail the specific steps to be taken for a missed dose of Termisil, depending on whether the tablet or topical form is being used. This information, including guidance on when to skip a dose, is available in the official prescribing information.


Q: Is the topical Termisil cream the same as the oral tablet version?

No, they are not the same product. While both contain the same active ingredient, the topical cream is used to treat superficial fungal skin infections, whereas the oral tablet is for systemic infections, such as those affecting the nails. They are not interchangeable.


Q: Does the taste disturbance side effect from Termisil ever become permanent?

Taste changes or loss (dysgeusia or ageusia) usually resolve after stopping the medication. However, official regulatory documents note that in rare post-marketing cases, these sensory changes have been reported to be prolonged or permanent.


Q: Is it safe to consume caffeine or alcohol while taking Termisil tablets?

Official warnings indicate that due to the risk of liver injury associated with this medication, and its contraindication in patients with existing liver disease, combining it with alcohol may increase potential risk.


Q: How long does it usually take to see visible improvement after starting Termisil?

Visible improvement for infections like nail fungus usually takes some months, often after the course of treatment is completed. This is because the medication stays present in the skin and nails, but clearance relies on the slow process of healthy new tissue growing out.


Q: Does Termisil make the skin more sensitive to sun exposure?

Official post-marketing reports have indicated that photosensitivity reactions can occur with Termisil. This suggests a potential for increased sensitivity to sun exposure while using the medication.


Q: Can topical Termisil be used for conditions like athlete's foot (tinea pedis)?

Yes, the various topical formulations of Termisil, such as the cream, gel, or solution, are specifically indicated for the local treatment of athlete's foot (tinea pedis), as well as jock itch and ringworm.


Q: Are there different storage requirements for Termisil tablets versus the cream/topical form?

Yes, both the tablets and topical forms must be stored at controlled room temperature and protected from light. However, official rules specifically require that topical formulations must be protected from freezing, which is a constraint not applied to the tablets.


Q: Why is Termisil sometimes prescribed for a shorter duration, like for ringworm of the body?

The length of treatment is fixed based on the type and location of the fungal infection. Superficial infections like ringworm of the body (tinea corporis) typically require a much shorter course of oral treatment, often 2 to 4 weeks, compared to the 6 or 12 weeks needed for nail infections.


Q: Does Termisil affect how certain foods are absorbed?

The oral tablets can generally be taken either with or without food. However, the oral granules, which are used for children, must be sprinkled onto a spoonful of soft, non-acidic food before being swallowed immediately.


Q: Is there any risk of developing depression or mood changes while on Termisil?

Official post-marketing reports have included cases of depressive symptoms and anxiety. These changes are sometimes reported as secondary effects related to weight loss and appetite issues that can result from taste or smell disturbances.


Q: Can Termisil cause hair loss as a side effect?

Official regulatory documents and post-marketing experience with oral terbinafine have included reports of hair loss (alopecia) occurring as a possible side effect.


Q: What are the specific signs of a 'lupus-like syndrome' that are associated with Termisil?

Official warnings state that the medication may trigger or worsen conditions like cutaneous and systemic lupus erythematosus. Signs that could suggest this include chronic fatigue, joint or muscle pain, or the development of a rash.


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

The drug accumulates in fat, skin, and nails. While the drug level in the blood drops off quickly (effective half-life is about 36 hours), it has a terminal half-life of 200–400 hours as it slowly eliminates from these tissues.


Q: Can Termisil cause other senses, like smell, to be affected?

Yes, official reports confirm that Termisil has been associated with disturbances in the sense of smell (anosmia), in addition to the more commonly known taste disturbances. Visual disturbances and hearing impairment have also been reported.


Q: Is it important to take Termisil at the exact same time every day?

The official direction is to take the tablet once daily. A consistent schedule is often suggested to support patient adherence and maintain steady drug levels.


Q: What are the considerations for using Termisil in older patients?

Official studies indicate that the drug's blood concentrations do not show clinically relevant changes based solely on age. Therefore, no automatic dose adjustment is typically needed for older patients unless they have other underlying conditions.


Q: Is Termisil effective for non-fungal nail conditions?

No, Termisil is specifically indicated for fungal infections of the nail (onychomycosis) caused by dermatophytes. It is not approved or effective for nail conditions that are not caused by a fungus.


Q: Does the topical Termisil product have fewer or different side effects than the oral tablets?

Yes, the side effect profile differs significantly. The topical product mainly lists local skin reactions like burning or irritation at the application site, while the oral tablet carries risks for serious systemic effects like liver injury, taste loss, and blood disorders.


Q: Can people with kidney issues use Termisil safely?

The official label states the oral tablet is not recommended for patients with significantly reduced kidney function (creatinine clearance less than 50 mL/min).

How should Termisil be stored and disposed of?

Termisil (terbinafine) tablets must be stored at controlled room temperature, generally maintained between 20 C and 25 C (68 F and 77 F), with brief excursions permitted up to 30 C.

The medication must be kept in its original container and the container must be tightly closed to protect the contents from light, moisture, and excess heat. Topical formulations, like cream, must be protected from freezing.

Official Storage & Disposal Rules

Requirement Type Official Constraints
Child Safety Must be kept out of the sight and reach of children.
Disposal Do not dispose of in household trash or via wastewater; dispose of according to local pharmaceutical waste regulations.

Any unused or expired product must be managed through designated disposal protocols, such as drug take-back programs, to comply with environmental guidelines.

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

Available in countries:

Equivalent of Termisil found in:

A-Z Index: