Terbinafine may be taken with food or on an empty stomach.

To help clear up your infection completely, it is very important that you keep taking this medicine for the full time of treatment , even if your symptoms begin to clear up or you begin to feel better after a few days. Since fungus infections may be very slow to clear up, you may need to take this medicine for several weeks or months. If you stop taking this medicine too soon, your symptoms may return.

This medicine works best when there is a constant amount in the blood. To help keep the amount constant, do not miss any doses . Also, it is best to take the doses at the same times every day. If you need help in planning the best time to take your medicine, check with your health care professional.

Dosing

The dose of terbinafine may be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of terbinafine. Your dose may be different if you have kidney or liver disease. If your dose is different, do not change it unless your doctor tells you to do so.

The number of tablets that you take depends on the strength of the medicine. Also, the length of time you take the medicine depends on the medical problem for which you are taking terbinafine.

• For oral dosage form (tablets):
  • For onychomycosis (fungus infections of the fingernails or toenails):
    • Adults and teenagers 250 milligrams (mg) once a day for six to twelve weeks.
    • Children Use and dose must be determined by the doctor.
  • For tinea corporis (ringworm of the body):
    • Adults and teenagers 250 mg once a day for two to four weeks.
    • Children Use and dose must be determined by the doctor.
  • For tinea cruris (ringworm of the groin; jock itch):
    • Adults and teenagers 250 mg once a day for two to four weeks.
    • Children Use and dose must be determined by the doctor.
  • For tinea pedis (ringworm of the foot; athlete's foot):
    • Adults and teenagers 250 mg once a day for two to six weeks.
    • Children Use and dose must be determined by the doctor.

Missed dose

If you miss a dose of this medicine, take it as soon as possible. This will help to keep a constant amount of medicine in the blood. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store this medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For terbinafine, the following should be considered:

Allergies Tell your doctor if you have ever had any unusual or allergic reaction to terbinafine. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy Terbinafine has not been studied in pregnant women. Before taking any medicine, make sure your doctor knows if you are pregnant or if you may become pregnant.

Breast-feeding Terbinafine passes into breast milk. Mothers who are taking this medicine and wish to breast-feed should discuss this with their doctor.

Children Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of terbinafine in children with use in other age groups.

Older adults Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of terbinafine in the elderly with use in other age groups.

Other medicines Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking terbinafine, it is especially important that your health care professional know if you are taking any of the following:

• Acetaminophen (e.g., Tylenol) (with long-term, high-dose use) or
• Amiodarone (e.g., Cordarone) or
• Anabolic steroids (nandrolone [e.g., Anabolin], oxandrolone [e.g., Anavar], oxymetholone [e.g., Anadrol], stanozolol [e.g., Winstrol]) or
• Androgens (male hormones) or
• Antithyroid agents (medicine for overactive thyroid) or
• Carmustine (e.g., BiCNU) or
• Chloroquine (e.g., Aralen) or
• Dantrolene (e.g., Dantrium) or
• Daunorubicin (e.g., Cerubidine) or
• Estrogens (female hormones) or
• Etretinate (e.g., Tegison) or
• Gold salts (medicine for arthritis) or
• Hydroxychloroquine (e.g., Plaquenil) or
• Mercaptopurine (e.g., Purinethol) or
• Methotrexate (e.g., Mexate) or
• Methyldopa (e.g., Aldomet) or
• Naltrexone (e.g., Trexan) (with long-term, high-dose use) or
• Other anti-infectives by mouth or by injection (medicine for infection) or
• Phenothiazines (acetophenazine [e.g., Tindal], chlorpromazine [e.g., Thorazine], fluphenazine [e.g., Prolixin], mesoridazine [e.g., Serentil], perphenazine [e.g., Trilafon], prochlorperazine [e.g., Compazine], promazine [e.g., Sparine], promethazine [e.g., Phenergan], thioridazine [e.g., Mellaril], trifluoperazine [e.g., Stelazine], triflupromazine [e.g., Vesprin], trimeprazine [e.g., Temaril]) or
• Plicamycin (e.g., Mithracin) Use of these medicines with terbinafine may increase the chance of side effects affecting the liver

• Azole antifungals (fluconazole [e.g., Diflucan], itraconazole [e.g., Sporanox], ketoconazole [e.g., Nizoral]) or
• Chloramphenicol (e.g., Chloromycetin) or
• Cimetidine (e.g., Tagamet) or
• Clarithromycin (e.g., Biaxin) or
• Diltiazem (e.g., Cardizem) or
• Erythromycins (e.g., EES, E-Mycin) or
• Isoniazid (e.g., INH, Nydrazid) or
• Quinine (e.g., Quinamm) or
• Ranitidine (e.g., Zantac) or
• Verapamil (e.g., Calan) Use of these medicines with terbinafine may increase the chance of side effects of terbinafine

• Carbamazepine (e.g., Tegretol) or
• Corticosteroids (cortisone-like medicine) or
• Griseofulvin (e.g., Fulvicin, Grisovin) or
• Phenobarbital (e.g., Luminal) or
• Phenylbutazone (e.g., Butazolidin) or
• Primidone (e.g., Mysoline) or
• Rifampin (e.g., Rifadin) Use of these medicines with terbinafine may prevent terbinafine from working properly

• Disulfiram (e.g., Antabuse) or
• Divalproex (e.g., Depakote) or
• Oral contraceptives (birth control pills) containing estrogen or
• Valproic acid (e.g., Depakene) Use of these medicines with terbinafine may increase the chance of side effects of terbinafine, especially those affecting the liver

• Phenytoin (e.g., Dilantin) Use of this medicine with terbinafine may prevent terbinafine from working properly and may increase the chance of side effects affecting the liver

• Alcohol abuse (or history of) Problems with alcohol may increase the chance of side effects caused by terbinafine
• Kidney disease or
• Liver disease, active or chronic Terbinafine is not recommended for patients with liver or kidney problems