Terbinafine is both an over-the-counter and a prescription medicine used to treat fungal infections. The over-the-counter forms (cream, gel, sprays) are used to treat itching, burning, cracking and scaling caused by athlete's foot, jock itch, and ringworm. The prescription forms (tablets and oral granules) are used to treat fingernail and toenail fungal infections and a fungal infection of the scalp that usually occurs in children. This medication page refers to the prescription form of terbinafine.
Terbinafine belongs to a group of drugs called antifungals. It works by stopping the growth of fungi.
Terbinafine tablets are taken once daily for up to 12 weeks, with or without food. Terbinafine oral granules are sprinkled on food and taken by mouth once daily.
Common side effects of terbinafine include headache.
Terbinafine Genetic Information
CYP2D6 is a protein in your body that is involved in the elimination of terbinafine and other drugs from your body. Some patients have less of this protein in their bodies, affecting how much of the drug gets eliminated. Levels of CYP2D6 can vary greatly between individuals, and those having less of this protein are known as "poor metabolizers."
CYP2D6 testing is done to determine whether you are a poor metabolizer. If you are a poor metabolizer, the levels of terbinafine in your blood can become too high. As a result you may be at an increased risk of having more side effects from terbinafine.
Your doctor may adjust your dose of terbinafine if you are a poor metabolizer.
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Uses of Terbinafine
Terbinafine is a prescription antifungal medicine used to treat fungal infections of the fingernails and toenails. The oral granule form is approved to treat tinea capitis (a fungal infection of the scalp hair follicles) in patients 4 years of age and older.
This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.
Terbinafine Brand Names
Terbinafine Drug Class
Terbinafine is part of the drug class:
Side Effects of Terbinafine
The most common side effects of terbinafine tablets include:
- ithcing and rash
- liver enzyme abnormalities
- taste disturbance
- abdominal pain
- flatulence (gas)
The most common side effects of terbinafine oral granules include:
- upper respiratory tract infection
- abdominal pain
Tell your doctor if you have any side effect that bothers you or that does not go away.
These are not all of the possible side effects of terbinafine. For information, ask your doctor or pharmacist.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Tell your doctor about all the medicines you take, including prescription and nonprescription medicines, vitamins, and herbal supplements. Terbinafine may affect the way other medicines work and other medicines may affect how terbinafine works. Especially tell your doctor if you take:
- a medicine for depression
- a medicine for high blood pressure
- a medicine for heart problems
- desipramine (Norpramin)
- cyclosporine (Gengraf, Neoral, Sandimmune)
- fluconazole (Diflucan)
- rifampin (Rifater, Rifamate, Rimactane, Rifadine)
- cimetidine (Tagamet)
This is not a complete list of terbinafine interactions. Ask your doctor or pharmacist for more information.
Terbinafine may cause serious side effects, including:
- liver problems that can lead to the need for liver transplant, or death. Your doctor should do a blood test to check you for liver problems before you take terbinafine. Tell your doctor right away if you get any of these symptoms of a liver problem:
- upper right stomach (abdominal) pain
- poor appetite
- yellowing of your skin or eyes (jaundice)
- dark (tea-colored) urine
- pale or light colored stools
- change in taste or loss of taste may happen with terbinafine. This usually improves within several weeks after stopping terbinafine, but may last for a long time or may become permanent. Tell your doctor if you have:
- change in taste or loss of taste
- poor appetite
- unwanted weight loss
- change in smell or loss of smell may happen with terbinafine. This may improve after stopping terbinafine, but may last for a long time or may become permanent.
- depressive symptoms. Tell your doctor right away if you have any of these signs or symptoms:
- feel sad or worthless
- change in sleep pattern
- loss of energy or interest in daily activities
- mood changes
- serious skin or allergic reactions. Tell your doctor right away or get emergency help if you get any of these symptoms:
- skin rash
- sores in your mouth, or your skin blisters and peels
- swelling of your face, eyes, lips, tongue or throat, trouble swallowing or breathing
- new or worsening lupus (autoimmune disease). Stop taking terbinafine and tell your doctor if you experience any of the following:
- progressive skin rash that is scaly, red, shows scarring, or loss of pigment
- unusual sensitivity to the sun that can lead to a rash
Do not take terbinafine if you are allergic to terbinafine hydrochloride when taken by mouth.
Terbinafine Food Interactions
Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of terbinafine, there are no specific foods that you must exclude from your diet when receiving terbinafine.
Before you take terbinafine, tell your doctor if you:
- have or had liver problems
- have a weakened immune system (immunocompromised)
- have lupus (an autoimmune disease)
- have kidney problems
- have any other medical conditions
- are pregnant or breastfeeding
Tell your doctor about all the medicines you take, including prescription and nonprescription medicines, vitamins, and herbal supplements.
Terbinafine and Pregnancy
Tell your doctor if you are pregnant or plan to become pregnant.
The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.
Terbinafine falls into category B. There are no good studies that have been done in humans with this Terbinafine. In animal studies, pregnant animals were given this medication, and the babies did not show any medical issues related to this medication.
Terbinafine and Lactation
Tell your doctor if you are breastfeeding or plan to breastfeed. Some terbinafine passes into your milk and may harm your baby. Talk to your doctor about the best way to feed your baby if you take terbinafine.
Take terbinafine exactly as your doctor tells you to take it.
- Terbinafine comes as a tablet that you take by mouth.
- Terbinafine is usually taken:
- 1 time each day for 6 weeks to treat fungal infections of your fingernail, or
- 1 time each day for 12 weeks to treat fungal infections of your toenail
- You can take terbinafine with or without food.
- If you forget to take terbinafine, take your tablets as soon as you remember, unless it is less than 4 hours before your next dose is due. In this case, wait and take your next dose at the usual time.
Terbinafine Oral Granules
Terbinafine comes as oral granules that are sprinkled on food and taken by mouth.
One to two packets should be taken each day with a soft non-acidic food (see instructions below). If two packets are required with each dose, you may either sprinkle the content of both packets on one spoonful of non-acidic food, or sprinkle the contents of both packets on two spoonfuls of non-acidic food as directed below.
- Hold packet with cut line on top.
- Shake packet gently to settle contents.
- Tear packet open along cut line, or use scissors to cut across line.
- Carefully pour entire contents of packet onto a spoonful of a soft food, such as pudding or other soft, non-acidic food such as mashed potatoes (do not use applesauce or a fruit-based food).
- Make sure that no granules remain in the packet.
- Swallow combination of food and granules without chewing.
Take terbinafine exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.
The dose of terbinafine your doctor prescribes will be determined based on the type of fungal infection you have and other medical conditions you have. The dose is also dependent upon weight (when choosing a dose for children) and other medications you are taking.
- Terbinafine Dosage - Fingernail Fungus Infection - 250 mg once daily for six weeks
- Terbinafine Dosage for Toenail Fungus Infection - 250 mg once daily for 12 weeks
- Terbinafine Dosage for Ringworm of the Scalp - Oral Granule dosage based on child's weight. Usually taken for 6 weeks.
If you take too much terbinafine, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.
- Store terbinafine at a temperature.
- Keep terbinafine in a tightly closed container and away from light.
- Keep terbinafine and all medicines out of the reach of children.