SIDE EFFECTS: Diarrhea or stomach upset may occur. If either of these effects lasts or gets worse, tell your doctor or pharmacist promptly. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Changes in your sense of taste/smell or loss of taste/smell may occur. These side effects may improve after stopping terbinafine, but can last for a long time or become permanent. Tell your doctor right away if you notice either of these side effects. Tell your doctor right away if you have any serious side effects, including: vision changes, mental/mood changes (such as depression), unexplained bleeding/bruising, unusual tiredness, signs of kidney problems (such as change in the amount of urine). Terbinafine may rarely cause serious (possibly fatal) liver disease. Get medical help right away if you have any symptoms of liver damage, such as: nausea/vomiting that doesn't stop, loss of appetite, severe stomach/abdominal pain, yellowing eyes/skin, dark urine. A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: fever, swollen lymph nodes, rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking terbinafine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. Before using this medication, tell your doctor or pharmacist your medical history, especially of: immune system problems, kidney disease, liver disease, lupus. Limit alcoholic beverages. Daily use of alcohol may increase your chance for serious side effects. This medication may make you more sensitive to the sun. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell your doctor right away if you get sunburned or have skin blisters/redness. During pregnancy, this medication should be used only when clearly needed. Fungal nail infection treatment can usually wait until after you have had your baby. Discuss the risks and benefits with your doctor. This medication passes into breast milk and may have undesirable effects on a nursing infant. Therefore, breast-feeding is not recommended while using this drug. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. Some products that may interact with this drug include: warfarin, drugs affecting liver enzymes that remove terbinafine from your body (such as amiodarone, cimetidine, rifampin, azole antifungals such as fluconazole/ketoconazole), drugs removed from your body by certain liver enzymes (such as tricyclic antidepressants, SSRI antidepressants, beta blockers, dextromethorphan, thioridazine, drugs to treat heart rhythm problems, monoamine oxidase inhibitors type B such as rasagiline).

OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.