Why is this medication prescribed?

Terbinafine is used to treat fungal infections of the toenail and fingernail. Terbinafine is in a class of medications called antifungals. It works by stopping the growth of fungi.

How should this medicine be used?

Terbinafine comes as a tablet to take by mouth. It is usually taken once a day for 6 weeks for fingernail fungus and once a day for 12 weeks for toenail fungus. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take terbinafine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Your fungus may not be completely cured until a few months after you finish taking terbinafine. This is because it takes time for a healthy nail to grow in.

Other uses for this medicine

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What special precautions should I follow?

Before taking terbinafine,

• tell your doctor and pharmacist if you are allergic to terbinafine or any other medications.

• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking. Be sure to mention any of the following: anticoagulants (blood thinners) such as warfarin (Coumadin); antidepressants such as amitriptyline (Elavil), amoxapine (Asendin), clomipramine (Anafranil), desipramine (Norpramin), doxepin (Adapin, Sinequan), imipramine (Tofranil), nortriptyline (Aventyl, Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil); beta-blockers such as atenolol (Tenormin), labetalol (Normodyne), metoprolol (Lopressor, Toprol XL), nadolol (Corgard), and propranolol (Inderal); cimetidine (Tagamet); medications that suppress the immune system such as azathioprine (Imuran), cyclosporine (Neoral, Sandimmune), methotrexate (Rheumatrex), sirolimus (Rapamune), and tacrolimus (Prograf); rifampin (Rifadin, Rimactane); and selegiline (Eldepryl). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.

• tell your doctor if you have or have ever had kidney or liver disease, human immunodeficiency virus (HIV), or acquired immunodeficiency syndrome (AIDS).

• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking terbinafine, call your doctor. You should not take terbinafine while breast-feeding.

What special dietary instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can this medication cause?

Terbinafine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• diarrhea

• upset stomach

• stomach pain

• rash

• itching

• hives

• changes in taste or loss of taste

Some side effects can be serious. The following symptoms are uncommon, but if you experience any of them, call your doctor immediately:

• upset stomach that does not go away

• loss of appetite

• extreme tiredness

• vomiting

• pain in the right upper part of the stomach

• dark urine

• pale stools

• severe skin rash that keeps getting worse

• fever, sore throat, and other signs of infection

Terbinafine may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].

What storage conditions are needed for this medicine?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

What other information should I know?

Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your body's response to terbinafine.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.