Generic Name: Terbinafine Brand Name(s): Generics only. No brands available.


What is terbinafine used for?

Terbinafine is commonly used for treating certain fungal infections of the fingernails or toenails. It may also be used for other conditions as determined by your doctor.

Terbinafine is an antifungal agent. It works by killing sensitive fungi.

How should I take terbinafine?

Use terbinafine as directed by your doctor. Check the label on the medicine for exact dosing instructions.

To use the tablets: Take by mouth with or without food. The tablets are taken for different amounts of time depending on your condition. The full benefit may not be seen for several months after stopping treatment. This includes the time period necessary for healthy nails to grow.

To use the nail lacquer: Use at bedtime, unless your doctor tells you otherwise. Wash and dry the affected nails, then apply a thin coat of medicine.

Do not apply the nail lacquer to a wound, or to broke or damaged skin.

Use the nail lacquer until a new, healthy nail has grown, unless your doctor tells you otherwise. This usually takes 6 to 12 months, depending on your condition.

To clear up your infection completely, take terbinafine for the full course of treatment. Keep taking it even if you begin to see improvement before the end of your therapy.

How do I store terbinafine?

Terbinafine is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store terbinafine in the bathroom or the freezer. There may be different brands of terbinafine that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush terbinafine down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using terbinafine?

Before using this drug, tell your doctor if:

  • You are pregnant or breastfeeding. This is because, while you are expecting or feeding a baby, you should only take medicines on the recommendation of a doctor.
  • You are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • You have allergy with any of active or inactive ingredients of terbinafine or other medications.
  • You have any other illnesses, disorders, or medical conditions.
  • You have a history of kidney or liver problems, lupus, depression, psoriasis, alcohol abuse or dependence, or blood problems (e.g., anemia).
  • You have a weakened immune system or low white blood cell counts.
  • You experience dizziness while taking terbinafine, use caution. Do not drive or perform other possibly unsafe tasks.
  • You take a medicine that contains caffeine or if you consume large amounts of food or drink that contain caffeine (e.g., coffee, tea, cocoa, cola, chocolate).

Terbinafine only works against fungal infections; it does not treat bacterial or viral infections (e.g., the common cold).

Do not take more than the recommended dose or use for longer than prescribed without checking with your doctor.

Be sure to use terbinafine for the full course of treatment. If you do not, the medicine may not clear up your infection completely. The fungus could also become less sensitive to this or other medicines. This could make the infection harder to treat in the future.

Very bad skin reactions (e.g., Stevens-Johnson syndrome/toxic epidermal necrolysis) that include skin rash with or without liver, lung, kidney, and/or heart problems have occurred in patients taking terbinafine. These reactions can cause very bad health problems that may not go away and sometimes death. Get medical help right away if you have red, swollen, blistered, or peeling skin; fever; red or irritated eyes; sores in your mouth, throat, nose, or eyes; or swollen lymph glands (with or without other unusual side effects).

Terbinafine may lower the ability of your body to fight infection. Tell your doctor if you notice signs of infection like fever, sore throat, rash, or chills.

Tell your doctor or dentist that you take terbinafine before you receive any medical or dental care, emergency care, or surgery.

Taste changes (e.g., taste loss) or changes in smell (e.g., loss of smell) have been reported in patients taking terbinafine. These effects may resolve after you stop taking terbinafine, but may last for a long time (e.g., more than 1 year), or may become permanent. Tell your doctor right away if you experience changes in smell, taste changes, poor appetite, unwanted weight loss, anxiety, or mood changes (e.g., symptoms of depression).

Terbinafine may cause you to become sunburned more easily. Avoid the sun, sunlamps, or tanning booths until you know how you react to terbinafine. Use a sunscreen or wear protective clothing if you must be outside for more than a short time.

Rarely, terbinafine may cause severe or even fatal liver problems. If liver problems occur, they may be more severe in patients who have other active liver problems or a history of long-term liver problems. Discuss any questions or concerns with your doctor.

The nail lacquer is for external use only. Do not get it in your eyes, nose, or mouth. If you get it in any of these areas, rinse right away with cool water.

You may apply nail polish on top of the nail lacquer.

Unless you are washing your hands, use gloves while using water or chemical substances to avoid accidentally washing the nail lacquer off. Wearing cotton under the gloves is preferred.

The nail lacquer is flammable. Do not store or use near an open flame or while smoking.

Lab tests, including liver function and complete blood cell counts, may be performed while you use terbinafine. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.

Terbinafine should be used with extreme caution in CHILDREN; safety and effectiveness in children have not been confirmed.

Is it safe during pregnancy or breastfeeding?

There are no adequate studies in women for determining risk when using terbinafine during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking terbinafine. Terbinafine is pregnancy risk category B, according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk
  • B=No risk in some studies
  • C=There may be some risk
  • D=Positive evidence of risk
  • X=Contraindicated
  • N=Unknown

Side effects

What side effects can occur from terbinafine?

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most common side effects persist or become bothersome:

  • Diarrhea
  • Gas
  • Headache
  • Indigestion
  • Mild stomach pain
  • Nausea

Seek medical attention right away if any of these severe side effects occur:

  • Severe allergic reactions (rash; hives; itching; difficulty breathing or swallowing; tightness in the chest; swelling of the mouth, face, lips, throat, or tongue; unusual hoarseness)
  • Burning, numbness, or tingling
  • Mental or mood changes (e.g., depression, restlessness, sadness, worthlessness)
  • New or worsening symptoms of lupus (e.g., butterfly-shaped rash on the face, joint pain, seizures, skin color changes, unusual sensitivity to the sun)
  • Pale skin or nail beds
  • Severe muscle or joint pain or tenderness
  • Severe or persistent stomach pain (with or without nausea or vomiting)
  • Sleep problems
  • Symptoms of liver problems (e.g., dark urine; loss of appetite; pale stools; unexplained, persistent nausea; vomiting; yellowing of the skin or eyes)
  • Unusual bruising or bleeding
  • Unusual tiredness or weakness
  • Vision or hearing changes

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.


What drugs may interact with terbinafine?

Terbinafine may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Products that may interact with this drug are:

  • Amiodarone, cimetidine, fluconazole, or ketoconazole because they may increase the risk of terbinafine’s side effects.
  • Rifampin because it may decrease terbinafine’s effectiveness.
  • Antiarrhythmics (e.g., flecainide, propafenone), beta-blockers (e.g., metoprolol), dextromethorphan, monoamine oxidase type B (MAO-B) inhibitors (e.g., selegiline), selective serotonin reuptake inhibitors (SSRIs) (e.g., fluoxetine), or tricyclic antidepressants (e.g., amitriptyline, desipramine) because the risk of their side effects may be increased by terbinafine.
  • Anticoagulants (e.g., warfarin) because their effectiveness may be decreased or the risk of their side effects may be increased by terbinafine.
  • Cyclosporine or tamoxifen because their effectiveness may be decreased by terbinafine.

Does food or alcohol interact with terbinafine?

Terbinafine may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with terbinafine?

Terbinafine may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.


The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using terbinafine.

What is the dose of terbinafine for an adult?

Usual Adult Dose for Onychomycosis – Fingernail

Tablets: 250 mg orally once a day

Duration of therapy:

Fingernail onychomycosis: 6 weeks

Toenail onychomycosis: 12 weeks

Usual Adult Dose for Onychomycosis – Toenail

Tablets: 250 mg orally once a day

Duration of therapy:

Fingernail onychomycosis: 6 weeks

Toenail onychomycosis: 12 weeks

Usual Adult Dose for Tinea Capitis

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

Usual Adult Dose for Tinea Corporis

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

Usual Adult Dose for Tinea Cruris

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

Usual Adult Dose for Tinea Pedis

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

What is the dose of terbinafine for a child?

Usual 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

How is terbinafine available?

Terbinafine is available in the following dosage forms and strengths:

  • Tablet

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of terbinafine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.


Review Date: August 8, 2017 | Last Modified: August 14, 2017

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