TERBINAFINE HYDROCHLORIDE

Clinical summary

Indications and usage 1 INDICATIONS AND USAGE Terbinafine tablets are an allylamine antifungal indicated for the treatment of onychomycosis of the toenail or fingernail due to dermatophytes (tinea unguium) (1) Terbinafine tablets 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. Dosage and administration 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. Warnings and cautions 5 WARNINGS AND PRECAUTIONS Liver failure, sometimes leading to liver transplant or death, has occurred with the use of oral terbinafine. Obtain pretreatment serum transaminases. Prior to initiating treatment and periodically during therapy, assess liver function tests. Discontinue terbinafine tablets if liver injury develops. ( 5.1 ) Taste disturbance, including taste loss, has been reported with the use of terbinafine tablets. Taste disturbance can be severe, may be prolonged, or may be permanent. Discontinue terbinafine tablets if taste disturbance occurs. ( 5.2 ) Smell disturbance, including loss of smell, has been reported with the use of terbinafine tablets. Smell disturbance may be prolonged, or may be permanent. Discontinue terbinafine tablets if smell disturbance occurs. ( 5.3 ) Depressive symptoms have been reported with terbinafine use. Prescribers should be alert to the development of depressive symptoms. ( 5.4 ) Severe neutropenia has been reported. If the neutrophil count is less than or equal to 1000 cells/mm 3 , terbinafine tablets should be discontinued. ( 5.5 ) Stevens-Johnson syndrome, toxic epidermal necrolysis, erythema multiforme, exfoliative dermatitis, bullous dermatitis, and drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome have been reported with oral terbinafine use. If signs or symptoms of drug reaction occur, treatment with terbinafine tablets should be discontinued. ( 5.6 ) 5.1 Hepatotoxicity Terbinafine tablets are contraindicated for patients with chronic or active liver disease. Before prescribing terbinafine tablets, perform liver function tests because hepatotoxicity may occur in patients with and without preexisting liver disease. Cases of liver failure, some leading to liver transplant or death, have occurred with the use of terbinafine tablets in individuals with and without preexisting liver disease. In the majority of liver cases reported in association with use of terbinafine tablets, the patients had serious underlying systemic conditions. The severity of hepatic events and/or their outcome may be worse in patients with active or chronic liver disease. Periodic monitoring of liver function tests is recommended. Discontinue terbinafine tablets if biochemical or clinical evidence of liver injury develops. Warn patients prescribed terbinafine tablets and/or their caregivers to report immediately to their healthcare providers any symptoms or signs of persistent nausea, anorexia, fatigue, vomiting, right upper abdominal pain or jaundice, dark urine, or pale stools. Advise patients with these symptoms to discontinue taking oral terbinafine, and immediately evaluate the patient's liver function. 5.2 Taste Disturbance Including Loss of Taste Taste disturbance, including taste loss, has 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. Taste disturbance may resolve within several weeks after discontinuation of treatment, but may be prolonged (greater than 1 year), or may be permanent. If symptoms of a taste disturbance occur, terbinafine tablets should be discontinued. 5.3 Smell Disturbance Including Loss of Smell Smell disturbance, including loss of smell, has been reported with the use of terbinafine tablets. Smell disturbance may resolve after discontinuation of treatment, but may be prolonged (greater than 1 year), or may be permanent. If symptoms of a smell disturbance occur, terbinafine tablets should be discontinued. 5.4 Depressive Symptoms Depressive symptoms have occur