Terbinafine Dosage

Usual Adult Dose for Onychomycosis - Fingernail

Tablets: 250 mg orally once a day for 6 weeks

The optimal clinical effect is observed some months after mycological cure and completion of treatment. This is related to the time required for outgrowth of healthy nail.

Usual Adult Dose for Onychomycosis - Toenail

Tablets: 250 mg orally once a day for 12 weeks

The optimal clinical effect is observed some months after mycological cure and completion of treatment. This is related to the time required for outgrowth of healthy nail.

Usual Adult Dose for Tinea Capitis

Oral granules: 250 mg orally once a day for 6 weeks

Some evidence suggests that a longer duration of therapy (e.g., 6 to 8 weeks) or higher dosage may be necessary when tinea capitis is caused by Microsporum canis.

Usual Adult Dose for Cutaneous Candidiasis

Tablets: 250 mg orally once a day for 2 to 4 weeks

Usual Adult Dose for Tinea Corporis

Tablets: 250 mg orally once a day for 2 to 4 weeks

Usual Adult Dose for Tinea Cruris

Tablets: 250 mg orally once a day for 2 to 4 weeks

Usual Adult Dose for Tinea Pedis

Tablets: 250 mg orally once a day for 2 to 6 weeks

Usual Pediatric Dose for Tinea Capitis

Oral granules:
4 years or older:
Less than 25 kg: 125 mg orally once a day
25 to 35 kg: 187.5 mg orally once a day
Greater than 35 kg: 250 mg orally once a day

Duration: 6 weeks

Some evidence suggests that a longer duration of therapy (e.g., 6 to 8 weeks) or higher dosage may be necessary when tinea capitis is caused by Microsporum canis.

Renal Dose Adjustments

CrCl 50 mL/min or less: Not recommended.

Liver Dose Adjustments

Chronic or active liver disease: Not recommended.

Precautions

Cases of liver failure have occurred during postmarketing experience with oral terbinafine in patients with and without preexisting liver disease. Some of the cases progressed to death or liver transplantation. In most of the reported liver cases, patients had serious underlying systemic conditions. The severity of hepatic events and/or the outcome of such events may be worse in patients with active or chronic liver disease. Terbinafine is not recommended in patients with chronic or active liver disease and should be discontinued if biochemical or clinical evidence of liver injury develops. The manufacturer recommends that pretreatment liver function tests (ALT and AST) be obtained for all patients. Patients should be counseled to report any symptoms indicative of liver dysfunction (e.g., persistent nausea, anorexia, fatigue, vomiting, right upper abdominal pain, jaundice, dark urine, or pale stools). Patients with these symptoms should stop terbinafine and their liver function should be assessed at once.

In patients with either preexisting liver disease or renal impairment (CrCl 50 mL/min or less), the use of terbinafine has not been adequately studied, and therefore, is not recommended.

Taste disturbance (including taste loss) and smell disturbance (including loss of smell) have been reported with terbinafine. Taste disturbance may be severe enough to cause decreased food intake, weight loss, and depressive symptoms. Taste disturbance and smell disturbance may resolve following treatment discontinuation, but may be prolonged (greater than one year), or may be permanent. If symptoms of a taste and/or a smell disturbance develop, terbinafine should be discontinued.

Serious skin reactions, such as Stevens-Johnson syndrome and toxic epidermal necrolysis, have been reported during postmarketing experience. Terbinafine therapy should be stopped if progressive skin rash occurs.

Transient decreases in absolute lymphocyte counts and severe neutropenia (reversible upon drug discontinuation) have been reported with oral terbinafine. Monitoring of complete blood counts may be appropriate in immunocompromised patients receiving terbinafine for greater than 6 weeks. A complete blood count is recommended if clinical signs and symptoms suggestive of secondary infection develop. Terbinafine should be discontinued and supportive care should be initiated if the neutrophil count is 1000 cells/mm3 or less.

Precipitation and exacerbation of cutaneous and systemic lupus erythematosus have been reported during postmarketing experience. Terbinafine should be discontinued in patients with clinical signs and symptoms suggestive of lupus erythematosus.

Safety and efficacy of terbinafine tablets have not been established in pediatric patients (less than 18 years of age). Safety and efficacy of terbinafine oral granules have not been established in pediatric patients less than 4 years of age.

Dialysis

Data not available

Other Comments

Clinical resolution may not be observed until several weeks after mycological cure.

The oral granules should be taken with food. The contents of each packet should be sprinkled on a spoonful of pudding or other soft, nonacidic food (e.g., mashed potatoes) and the entire spoonful should be swallowed without chewing. Applesauce or fruit-based foods should not be used.

See also...