Terbinafine

1 INDICATIONS AND USAGE Terbinafine tablets, USP are indicated for the treatment of onychomycosis of the toenail or fingernail due to dermatophytes (tinea unguium). Prior to initiating treatment, appropriate nail specimens for laboratory testing [potassium hydroxide (KOH) preparation, fungal culture, or nail biopsy] should be obtained to confirm the diagnosis of onychomycosis. Terbinafine tablets are an allylamine antifungal indicated for the treatment of onychomycosis of the toenail or fingernail due to dermatophytes (tinea unguium).

2 DOSAGE AND ADMINISTRATION Prior to administering, evaluate patients for evidence of chronic or active liver disease. ( 2.1 ) Fingernail onychomycosis: One tablet, once daily for 6 weeks. ( 2.2 ) Toenail onychomycosis: One tablet, once daily for 12 weeks. ( 2.2 ) 2.1 Assessment Prior to Initiation Before administering terbinafine tablets, evaluate patients for evidence of chronic or active liver disease [see Contraindications (4) and Warnings and Precautions (5.1) ] . 2.2 Dosage Fingernail onychomycosis: One 250 mg tablet once daily for 6 weeks. Toenail onychomycosis: One 250 mg tablet once daily for 12 weeks. The optimal clinical effect is seen some months after mycological cure and cessation of treatment. This is related to the period required for outgrowth of healthy nail.

4 CONTRAINDICATIONS Terbinafine tablets are contraindicated in patients with: History of allergic reaction to oral terbinafine because of the risk of anaphylaxis [see Adverse Reactions (6.2) ] Chronic or active liver disease [see Warnings and Precautions (5.1) ] Chronic or active liver disease. ( 4 ) History of allergic reaction to oral terbinafine because of the risk of anaphylaxis. ( 4 )

Not available.

6 ADVERSE REACTIONS Common (greater than 2% of patients treated with terbinafine tablets) reported adverse events include headache, diarrhea, rash, dyspepsia, liver enzyme abnormalities, pruritus, taste disturbance, nausea, abdominal pain, and flatulence. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Exelan Pharmaceutical, Inc. at 1-866-604-3268 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The most frequently reported adverse events observed in the three US/Canadian placebo-controlled trials are listed in the Table 1. The adverse events reported encompass gastrointestinal symptoms (including diarrhea, dyspepsia, and abdominal pain), liver test abnormalities, rashes, urticaria, pruritus, and taste disturbances. Changes in the ocular lens and retina have been reported following the use of terbinafine tablets in controlled trials. The clinical significance of these changes is unknown. In general, the adverse events were mild, transient, and did not lead to discontinuation from study participation. Table 1. Most frequently reported adverse events observed in the 3 US/Canadian placebo-controlled trials Adverse Event Discontinuation Terbinafine Tablets Placebo Terbinafine Tablets Placebo (%) (%) (%) (%) n=465 n=137 n=465 n=137 Headache 12.9 9.5 0.2 0.0 Gastrointestinal Symptoms: Diarrhea 5.6 2.9 0.6 0.0 Dyspepsia 4.3 2.9 0.4 0.0 Abdominal Pain 2.4 1.5 0.4 0.0 Nausea 2.6 2.9 0.2 0.0 Flatulence 2.2 2.2 0.0 0.0 Dermatological Symptoms: Rash 5.6 2.2 0.9 0.7 Pruritis 2.8 1.5 0.2 0.0 Urticaria 1.1 0.0 0.0 0.0 Liver Enzyme Abnormalities* 3.3 1.4 0.2 0.0 Taste Disturbance 2.8 0.7 0.2 0.0 Visual Disturbance 1.1 1.5 0.9 0.0 *Liver enzyme abnormalities greater than or equal to 2x the upper limit of normal range. 6.2 Postmarketing Experience The following adverse events have been identified during post-approval use of terbinafine tablets. Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Blood and lymphatic system disorders: Pancytopenia, agranulocytosis, severe neutropenia, thrombocytopenia, anemia, thrombotic microangiopathy (TMA), including thrombotic thrombocytopenic purpura and hemolytic uremic syndrome [see Warnings and Precautions (5.5 , 5.8) ] Immune system disorders: Serious hypersensitivity reactions e.g angioedema and allergic reactions (including anaphylaxis), precipitation and exacerbation of cutaneous and systemic lupus erythematosus [see Warnings and Precautions (5.7) ], serum sickness-like reaction Psychiatric disorders: Anxiety and depressive symptoms independent of taste disturbance have been reported with use of terbinafine tablets. In some cases, depressive symptoms have been reported to subside with discontinuance of therapy and to recur with reinstitution of therapy [see Warnings and Precautions (5.4) ] Nervous system disorders: Cases of taste disturbance, including taste loss, have been reported with the use of terbinafine tablets. It can be severe enough to result in decreased food intake, weight loss, anxiety, and depressive symptoms. Cases of smell disturbance, including smell loss, have been reported with the use of terbinafine tablets [see Warnings and Precautions (5.2 , 5.3) ]. Cases of paresthesia and hypoesthesia have been reported with the use of terbinafine tablets. Eye disorders: Visual field defects, reduced visual acuity Ear and labyrinth disorders: Hearing impairment, vertigo, tinnitus Vascular disorders: Vasculitis Gastrointestinal disorders: Pancreatitis, vomiting Hepatobiliary disorders: Cases of liver failure some leading to liver transplant or death [see Warnings and Precautions (5.1) ], idiosyncratic and symptomatic hepatic injury. Cases of hepatitis, cholestasis, and increased hepatic enzymes [see Warnings and Precautions (5.1) ] have been seen with the use of terbinafine tablets. Skin and subcutaneous tissue disorders: Serious skin reactions [e.g., Stevens-Johnson syndrome, toxic epidermal necrolysis, erythema multiforme, exfoliative dermatitis, bullous dermatitis, and drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome] [see Warnings and Precautions (5.6) ], acute generalized exanthematous pustulosis, psoriasiform eruptions or exacerbation of psoriasis, photosensitivity reactions, hair loss Musculoskeletal and connective tissue disorders: Rhabdomyolysis, arthralgia, myalgia General disorders and administration site conditions: Malaise, fatigue, influenza-like illness, pyrexia Investigations: Altered prothrombin time (prolongation and reduction) in patients concomitantly treated with warfarin and increased blood creatine phosphokinase have been reported.