Indications of Terbinafine, Mechanism, Drug Interactions

Last updated: February 7, 2026Reviewed date: February 7, 2026Reading time: 8 min read
Patient Tools

Read, save, and share this guide

Use these quick tools to make this medical article easier to read, print, save, or share with a family member.

Patient Mode

Understand this article easily

Switch between simple English and easy Bangla patient notes. This is for education and does not replace a doctor consultation.

Indications of Terbinafine/Terbinafine is a synthetic allylamine derivative with antifungal activity. Terbinafine exerts its effect through inhibition of squalene epoxidase, thereby blocking the biosynthesis of ergosterol, an important component of fungal cell membranes. As a result, this agent disrupts fungal cell membrane synthesis and inhibits fungal growth. Terbinafine is an...

For severe symptoms, danger signs, pregnancy, child illness, or sudden worsening, seek urgent medical care.

বাংলা রোগী নোট এখনো যোগ করা হয়নি। পোস্ট এডিটরে “RX Bangla Patient Mode” বক্স থেকে সহজ বাংলা সারাংশ যোগ করুন।

এই তথ্য শিক্ষা ও সচেতনতার জন্য। এটি ডাক্তারি পরীক্ষা, রোগ নির্ণয় বা প্রেসক্রিপশনের বিকল্প নয়।

Article Summary

Indications of Terbinafine/Terbinafine is a synthetic allylamine derivative with antifungal activity. Terbinafine exerts its effect through inhibition of squalene epoxidase, thereby blocking the biosynthesis of ergosterol, an important component of fungal cell membranes. As a result, this agent disrupts fungal cell membrane synthesis and inhibits fungal growth. Terbinafine is an Allylamine Antifungal. The chemical classification of terbinafine is Allylamine. Terbinafine is an orally and topically active allylamine fungicidal agent which is used to treat...

Key Takeaways

  • This article explains Mechanism of Action of Terbinafine in simple medical language.
  • This article explains Indications of Terbinafine in simple medical language.
  • This article explains Contraindication of Terbinafine in simple medical language.
  • This article explains Dosage of Terbinafine in simple medical language.
Educational health guideWritten for patient understanding and clinical awareness.
Reviewed content workflowUse writer and reviewer profiles for stronger trust.
Emergency safety firstUrgent warning signs are highlighted below.

Seek urgent medical care if you notice

These warning signs are general safety guidance. Local emergency numbers and clinical judgment should always come first.

  • Severe symptoms, breathing difficulty, fainting, confusion, or rapidly worsening illness.
  • New weakness, severe pain, high fever, or symptoms after a serious injury.
  • Any symptom that feels urgent, unusual, or unsafe for the patient.
1

Emergency now

Use emergency care for severe, sudden, rapidly worsening, or life-threatening symptoms.

2

See a doctor

Book a professional medical evaluation if symptoms persist, worsen, recur often, affect daily activities, or occur in a high-risk patient.

3

Learn safely

Use this article to understand possible causes, tests, treatment options, prevention, and questions to ask your clinician.

Indications of Terbinafine/Terbinafine is a synthetic allylamine derivative with antifungal activity. Terbinafine exerts its effect through inhibition of squalene epoxidase, thereby blocking the biosynthesis of ergosterol, an important component of fungal cell membranes. As a result, this agent disrupts fungal cell membrane synthesis and inhibits fungal growth. Terbinafine is an Allylamine Antifungal. The chemical classification of terbinafine is Allylamine.

Terbinafine is an orally and topically active allylamine fungicidal agent which is used to treat superficial fungal infections of the skin and nails. Terbinafine has been clearly linked to rare instances of acute liver injury that can be severe and sometimes fatal.

Mechanism of Action of Terbinafine

Terbinafine is hypothesized to act by inhibiting squalene monooxygenase, thus blocking the biosynthesis of ergosterol, an essential component of fungal cell membranes. This inhibition also results in an accumulation of squalene, which is a substrate catalyzed to 2,3-oxy do squalene by squalene monooxygenase. The resultant high concentration of squalene and decreased amount of ergosterol are both thought to contribute to terbinafine’s antifungal activity.

Terbinafine hydrochloride (Lamisil) is a synthetic allylamine antifungal. It is highly lipophilic in nature and tends to accumulate in the skin, nails, and fatty tissues. Like other allylamines, terbinafine inhibits ergosterol synthesis by inhibiting the fungal squalene monooxygenase (squalene 2, 3-epoxidase), an enzyme that is part of the fungal cell wall synthesis pathway.

Indications of Terbinafine

  • For the treatment of dermatophyte infections of the toenail or fingernail caused by susceptible fungi. Also for the treatment of tinea capitis (scalp ringworm) and tinea corporis (body ringworm) or tinea cruris (jock itch).
  • Treatment of onychomycosis
  • Terbinafine hydrochloride is indicated to treat fungal skin and nail infections caused by Trichophyton species, Microsporum canis, Epidermophyton floccosum,[rx] and Tinea species.[rx] Terbinafine hydrochloride also treats yeast infections of the skin caused by Candida species and Malassezia furfur.12
  • Onychomycosis, Toenail
  • Tinea Capitis
  • Cutaneous Candidiasis
  • Onychomycosis, Fingernail
  • Tinea Corporis
  • Tinea Cruris
  • Tinea Pedis

Associated Conditions

  • Candidiasis, Cutaneous
  • Onychomycosis
  • Pityriasis Versicolor
  • Sporotrichosis
  • Tinea Capitis
  • Tinea Corporis
  • Tinea Cruris
  • Tinea Pedis
  • Severe Tinea Corporis
  • Severe Tinea Cruris
  • Severe Tinea Pedis

Contraindication of Terbinafine

  • Depression
  • Liver problems
  • Systemic lupus erythematosus
  • An autoimmune disease
  • Abnormal liver function tests
  • A significant drop in a certain type of white blood cell called a bacterial infection. সহজ বাংলা: ব্যাকটেরিয়ার বিরুদ্ধে লড়াই করা শ্বেত রক্তকণিকা।" data-rx-term="neutrophil" data-rx-definition="Neutrophil is a white blood cell important for fighting bacterial infection. সহজ বাংলা: ব্যাকটেরিয়ার বিরুদ্ধে লড়াই করা শ্বেত রক্তকণিকা।">neutrophil
  • Allergies to Terbinafine Terbinafine/Butenafine

Dosage of Terbinafine

Strengths: 250 mg; 125 mg; 187.5 mg

Onychomycosis – Fingernail

  • Tablets: 250 mg orally once a day

Duration of therapy

  • Fingernail onychomycosis: 6 weeks
  • Toenail onychomycosis: 12 weeks

Onychomycosis – Toenail

  • Tablets: 250 mg orally once a day

Duration of therapy

  • Fingernail onychomycosis: 6 weeks
  • Toenail onychomycosis: 12 weeks

Tinea Capitis

  • Oral granules: 250 mg orally once a day for 6 weeks

Tinea Corporis

  • Tablets: 250 mg orally once a day for 2 to 4 weeks

Tinea Cruris

  • Some experts recommend: Tablets: 250 mg orally once a day for 2 to 4 weeks

Tinea Pedis

  • Some experts recommend: Tablets: 250 mg orally once a day for 2 to 6 weeks

Pediatric Dose for Tinea Capitis

4 years or older: Oral granules:

  • Less than 25 kg: 125 mg orally once a day
  • 25 to 35 kg: 187.5 mg orally once a day
  • Greater than 35 kg: 250 mg orally once a day
  • Duration of therapy: 6 weeks

For Children, Some Experts Recommend:

  • Tablets: 5 mg/kg/day orally

Based on weight

  • 10 to 20 kg: 62.5 mg orally once a day
  • 21 to 40 kg: 125 mg orally once a day
  • 41 kg or more: 250 mg orally once a day

Duration of therapy

  • Trichophyton tonsurans infection: 2 to 4 weeks
  • Microsporum can is infection: Longer duration needed.S

Side  Effects of Terbinafine

The Most Common

  • signs of anemia (low red blood cells; e.g., dizziness,  pale skin, unusual tiredness or weakness, shortness of breath)
  • signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
  • signs of muscle breakdown (e.g., discolored urine, unexpected muscle pain, aches)
  • skin rash or itching
  • symptoms of blood disorders (such as sore throat, fever, chills, mouth sores, or unusual bleeding or bruising)
  • symptoms of liver problems (such as unusual fatigue, yellow eyes or skin, abdominal pain, dark urine, pale stools, itching, or loss of appetite)
  • vision changes
  • weight loss
  • signs of pancreatitis (e.g., abdominal pain on the upper left side, back pain, nausea, fever, chills, rapid heartbeat, swollen abdomen)
  • symptoms of a serious allergic reaction (such as hives, difficulty breathing, or swelling of the face or throat)
  • symptoms of a serious skin rash (such as redness, blistering, peeling, or loosening of skin)
  • bloating or feeling of fullness in the stomach
  • diarrhea
  • pain in the head or upper neck. সহজ বাংলা: মাথাব্যথা।" data-rx-term="headache" data-rx-definition="Headache means pain in the head or upper neck. সহজ বাংলা: মাথাব্যথা।">headache
  • heartburn
  • increased sensitivity to the sun
  • loss of appetite
  • nausea
  • stomach pain (mild)


Common

  • indigestion
  • inflammation of the joints
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • light-colored stools
  • lower back or side pain
  • muscle aches
  • painful or difficult urination
  • pains in the stomach, side, or abdomen, possibly radiating to the back
  • persistent loss of appetite
  • pinpoint red spots on the skin
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • red, scaling, or crusted skin
  • sores, ulcers, or white spots on the lips or in the mouth
  • sores, welting, or blisters
  • stomach pain, continuing
  • swollen glands
  • swollen lymph glands
  • tightness in the chest
  • troubled breathing with exertion
  • ulcers, sores, or white spots in the mouth
  • unexplained bleeding or bruising

Rare

  • burning
  • dryness
  • flaking or peeling skin
  • itching
  • other signs of skin irritation not present before use of this medication
  • peeling
  • rash
  • redness
  • scabs
  • skin discoloration
  • skin lesions
  • stinging
  • tingling
  • Body aches or pain
  • diarrhea
  • difficulty with breathing
  • ear congestion
  • a general feeling of discomfort or illness
  • headache
  • joint pain
  • loss of appetite
  • loss of voice
  • nasal congestion
  • nausea
  • runny nose
  • shivering
  • skin rash or itching
  • sneezing
  • sore throat
  • sweating
  • trouble with sleeping
  • Drug

Drug Interactions of Terbinafine

There may be an interaction between terbinafine and any of the following:

  • amiodarone
  • antipsychotic medications (e.g., chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
  • atomoxetine
  • azole antifungals (e.g., fluconazole, itraconazole, ketoconazole)
  • beta-adrenergic blockers (e.g., atenolol, propranolol, sotalol)
  • birth control pills
  • caffeine and products that contain caffeine
  • captopril
  • carbamazepine
  • carvedilol
  • chloroquine
  • chlorpheniramine
  • cimetidine
  • codeine
  • cyclosporine
  • dextromethorphan
  • doxepin
  • doxorubicin
  • fesoterodine
  • flecainide
  • MAO inhibitors type B (e.g., maprotiline, selegiline)
  • mercaptopurine
  • methamphetamine
  • mexiletine
  • mirtazapine
  • nefazodone
  • oxycodone
  • phenobarbital
  • phenytoin
  • pimozide
  • primaquine
  • primidone
  • procainamide
  • propafenone
  • rifabutin
  • rifampin
  • Saccharomyces boulardii
  • selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline)
  • tamoxifen
  • tamsulosin
  • tetrabenazine
  • theophylline
  • tolbutamide
  • tolterodine
  • tramadol
  • triazolam
  • tricyclic antidepressants (e.g., amitriptyline, desipramine)
  • venlafaxine
  • warfarin

Pregnancy Category of Terbinafine

FDA Pregnancy Category B

Pregnancy

This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding

This medication passes into breast milk. If you are a breast-feeding mother and are taking terbinafine, it may affect your baby. Women taking terbinafine tablets should not breast-feed. If you are using the cream or spray, talk to your doctor about whether you should continue breast-feeding. The safety and effectiveness of using this medication have not been established for children.


References

Doctor visit helper

Prepare before seeing a doctor

A simple rural-patient checklist to help you explain symptoms clearly, ask better questions, and avoid unsafe self-treatment.

Safety note: This is not a prescription or diagnosis. For severe symptoms, pregnancy danger signs, children with serious illness, chest pain, breathing difficulty, stroke-like weakness, or major injury, seek urgent care.

Which doctor may help?

Orthopedic doctor, rheumatologist, or physiotherapist depending on cause.

What to tell the doctor

  • Write which joints hurt, swelling, morning stiffness duration, fever, injury, and walking difficulty.
  • Bring X-ray, uric acid, ESR/CRP, rheumatoid factor, or previous reports if available.

Questions to ask

  • Is this injury, osteoarthritis, rheumatoid arthritis, gout, infection, or another cause?
  • Which exercises, supports, or lifestyle changes are safe?
  • Do I need blood tests or X-ray?

Tests to discuss

  • Joint examination and range of motion
  • X-ray when chronic arthritis or injury is suspected
  • ESR/CRP, uric acid, rheumatoid tests when inflammatory arthritis is suspected

Avoid these mistakes

  • Do not ignore hot swollen joint with fever.
  • Avoid repeated steroid injections/tablets without a clear diagnosis and follow-up.

Medicine safety and first-aid guide

This section is for patient education only. It does not replace a doctor, pharmacist, or emergency care.

Safe first steps

  • Avoid heavy lifting, sudden bending, and prolonged bed rest.
  • Use comfortable posture and gentle movement as tolerated.
  • Discuss physiotherapy, X-ray, or MRI only when clinically needed.

OTC medicine safety

  • For mild back pain, pain-relief medicine may be discussed with a doctor or pharmacist.
  • Avoid repeated painkiller use if you have kidney disease, stomach ulcer, uncontrolled blood pressure, or are taking blood thinners.

Avoid these mistakes

  • Do not start antibiotics without a proper medical decision.
  • Do not use steroid tablets or injections casually for quick relief.
  • Do not delay emergency care because of home remedies.

Get urgent help if

  • Back pain with leg weakness, numbness around private area, loss of urine/stool control, fever, cancer history, or major injury needs urgent care.
Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Orthopedic / spine specialist, physical medicine doctor, or qualified clinician
Tests to discuss with doctor
  • Neurological examination for leg power, sensation, reflexes, and straight leg raise
  • X-ray only if injury, deformity, long-lasting pain, or doctor suspects bone problem
  • MRI discussion if severe nerve symptoms, weakness, bladder/bowel problem, or persistent symptoms
Questions to ask
  • What is the most likely cause of my symptoms?
  • Which warning signs mean I should go to emergency care?
  • Which tests are really needed now?
  • Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?
  • Is physiotherapy, posture correction, or activity modification needed?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

Safe pathway to proper treatment

Care roadmap for: Indications of Terbinafine, Mechanism, Drug Interactions

Use this simple roadmap to understand the next safe steps. It is educational and does not replace examination by a doctor.

Go to emergency care if you notice:
  • Severe or rapidly worsening symptoms
  • Breathing difficulty, chest pain, fainting, confusion, severe weakness, major injury, or severe dehydration
Doctor / service to discuss: Qualified healthcare provider; specialist depends on symptoms and examination.
  1. Step 1

    Check danger signs first

    If danger signs are present, seek emergency care and do not wait for online information.

  2. Step 2

    Record the symptom story

    Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.

  3. Step 3

    Visit a qualified clinician

    A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.

  4. Step 4

    Do only useful tests

    Do tests after clinical assessment. Avoid unnecessary tests, random antibiotics, or repeated medicines without diagnosis.

  5. Step 5

    Follow up and return early if worse

    If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

Rural patient practical tips
  • Take a written symptom diary and all previous prescriptions/test reports.
  • Do not hide medicines already taken, even herbal or over-the-counter medicines.
  • Ask which warning signs mean urgent referral to hospital.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.

RX Patient Help

Ask a health question safely

Write your symptom story. A health professional or site editor can review it before any answer is prepared. This box is not for emergency care.

Emergency first: Severe chest pain, breathing trouble, unconsciousness, stroke signs, severe injury, heavy bleeding, or rapidly worsening symptoms need urgent local medical care now.

Frequently Asked Questions

Is this article a replacement for a doctor?

No. It is educational content only. Patients should consult a qualified clinician for diagnosis and treatment.

When should I seek urgent care?

Seek urgent care for severe symptoms, rapidly worsening condition, breathing difficulty, severe pain, neurological changes, or any emergency warning sign.

References

Add references, clinical guidelines, textbooks, journal articles, or trusted medical sources here. You can edit this area from the RX Article Professional Blocks panel.

More from this topic
  1. Positive Affirmations

    Repeating positive affirmations can help you push away negative feelings and feel better about yourself and your life. You can shift your mindset by replacing negative...

    February 25, 2024 • Rx Entrepreneurs, Leadership, Motivational Quotes, and Speech
  2. Benefits of Dating an Aquarius

    Dating an Aquarius will keep you on your toes because they constantly seek new adventures. As one of the most spontaneous, unpredictable zodiac signs, Aquarius views...

    February 25, 2024 • Rx Entrepreneurs, Leadership, Motivational Quotes, and Speech
  3. Libra’s Love for Balance and Harmony

    If you’re dating a Libra, you may have fallen in love with their kindness, generosity, and creative personality. Born between September 23 and October 22, Libras...

    February 25, 2024 • Rx Entrepreneurs, Leadership, Motivational Quotes, and Speech
  4. Numerology – How to Calculate Your Lucky Number

    A lucky number refers to specific numbers that play an essential role in your life, such as your birth date, life path number, or personality number....

    February 25, 2024 • Rx Entrepreneurs, Leadership, Motivational Quotes, and Speech
  5. Past Life Regression

    Have you ever wondered if there’s more to your story than meets the eye? What if the person you are today builds upon lifetimes of experiences,...

    February 25, 2024 • Rx Entrepreneurs, Leadership, Motivational Quotes, and Speech
  6. Positive Messages When You Need Encouragement

    We all face moments of doubt, fear, and uncertainty in life’s journey. During these times, we need a beacon of hope, a message of encouragement to...

    February 25, 2024 • Rx Entrepreneurs, Leadership, Motivational Quotes, and Speech
  7. Top 30 Seafood Spots in Iran

    Iran, with its diverse coastline along the Caspian Sea and the Persian Gulf, offers a treasure trove of seafood delights. From succulent fish and shrimp to...

    July 18, 2023 • Rx Entrepreneurs, Leadership, Motivational Quotes, and Speech
  8. Top 30 Shooting Spots in Malaysia Locations

    Malaysia is a haven for photography enthusiasts and filmmakers, boasting breathtaking landscapes, vibrant cities, and diverse cultural heritage. If you’re seeking the perfect shooting spots in...

    July 1, 2023 • Rx Entrepreneurs, Leadership, Motivational Quotes, and Speech
  9. Top 30 Horse Racing Destinations in Malaysia

    Horse racing is a popular sport in Malaysia, attracting enthusiasts and bettors from all walks of life. Whether you’re an avid fan of the sport or...

    July 1, 2023 • Rx Entrepreneurs, Leadership, Motivational Quotes, and Speech
  10. Top 30 Online Fantasy Sports in Malaysia

    Online fantasy sports have gained immense popularity in Malaysia, captivating sports enthusiasts and providing a unique platform to showcase their skills and knowledge. With numerous options...

    June 28, 2023 • Rx Entrepreneurs, Leadership, Motivational Quotes, and Speech