TINASIL

What it is

Tinasil contains terbinafine hydrochloride, a white to off-white, finely crystalline powder. Each tablet contains terbinafine hydrochloride equal to either 125 mg or 250 mg terbinafine base.

Approved indications

— Treatment in adults of ringworm (tinea corporis, tinea cruris and tinea pedis) due to infection caused by dermatophytes such as Trichophyton, Microsporum canis and Epidermophyton floccosum, where oral therapy is considered appropriate owing to the site, severity or extent of the infection, and the infection is not responsive to topical therapy. — Onychomycosis in adults (fungal infection of the nail) caused by dermatophyte fungi.

Dosing overview

For both skin infections and onychomycosis, the recommended adult dose is 250 mg once a day. For tinea pedis (interdigital, plantar/moccasin type), treatment duration is likely 2 to 6 weeks, and for tinea corporis and cruris, 2 to 4 weeks. For onychomycosis, the duration for successful treatment is usually between six weeks and three months, with infections of finger and toenails other than the big toe typically responding to shorter treatment, particularly in younger patients with normal nail outgrowth; in patients with slow nail growth, treatment for up to three months is usually adequate, but infections in the big toe or if nail growth is very poor may require treatment for up to 6 months.

Key safety warnings

Patients taking Tinasil are at risk of developing agranulocytosis, thrombocytopenia, pancytopenia and neutropenia, which are very rarely associated with terbinafine; the problem usually resolves within a few days to a week of withdrawal of Tinasil, and patients should be advised to report symptoms of infections. Cases of thrombotic thrombocytopenic purpura (TTP), some fatal, have been reported with terbinafine; Tinasil should be discontinued if clinical symptoms and laboratory findings consistent with TTP occur, and unexplained thrombocytopenia and anaemia should prompt further evaluation and consideration of the diagnosis of TTP. Serious skin reactions such as Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug rash with eosinophilia and systemic symptoms have been very rarely reported in patients taking Tinasil, and treatment should be discontinued if progressive skin rash occurs. Terbinafine should be used with caution in patients with pre-existing psoriasis or lupus erythematosus as precipitation and exacerbation of these conditions have been reported. Very rare cases of liver failure (some leading to liver transplant or death) have been reported with Tinasil use, with the majority of hepatic failure cases occurring in patients with underlying systemic conditions; patients should be warned to report immediately any symptoms of persistent nausea, anorexia, fatigue, vomiting, right upper abdominal pain or jaundice, dark urine or pale stools, and should discontinue taking Tinasil with immediate evaluation of hepatic function.

Contraindications

Tinasil is contraindicated in patients with hypersensitivity to terbinafine or to any of the excipients in the formulation. Tinasil is contraindicated in patients with severe, chronic, or active hepatic disease.

PBS listing

Tinasil 250 mg tablets are listed on the PBS with one item, restriction type authority required, at an ex-manufacturer price of A$11.88.

Regulatory history

Tinasil 250 mg tablets were first listed on the ARTG on 23 July 2004 under licence category RE (Restricted Eligibility).