Naftifine Drug Information

Naftifine hydrochloride gel USP, 2% is indicated for the treatment of interdigital tinea pedis caused by the organisms Trichophyton rubrum, Trichophyton mentagrophytes, and Epidermophyton floccosum. Naftifine Hydrochloride Gel USP, 2% is an allylamine antifungal indicated for the treatment of interdigital tinea pedis caused by the organisms Trichophyton rubrum, Trichophyton mentagrophytes, and Epidermophyton floccosum.

Apply a thin layer of naftifine hydrochloride gel, 2% once daily to the affected areas plus an approximate ½ inch margin of healthy surrounding skin for 2 weeks. For topical use only. Naftifine hydrochloride gel, 2% is not for ophthalmic, oral, or intravaginal use.

Apply a thin layer of naftifine hydrochloride gel, 2% once daily to the affected areas plus an approximate ½ inch margin of healthy surrounding skin for 2 weeks. For topical use only. Naftifine hydrochloride gel, 2% is not for ophthalmic, oral, or intravaginal use.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed 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 clinical practice. In two randomized, vehicle-controlled trials, 1143 subjects were treated with naftifine hydrochloride gel versus 571 subjects treated with the vehicle. The trial subjects were 12 to 92 years old, were primarily male (76%), and were 59% Caucasian, 38% Black or African American, and 23% Hispanic or Latino.

Subjects received doses once daily, topically, for 2 weeks to cover the affected skin areas plus a ½-inch margin of surrounding healthy skin. The most common adverse reactions were application site reactions which occurred at the rate of 2% in naftifine hydrochloride gel arm versus 1% in vehicle arm. Most adverse reactions were mild in severity.

In an open-label pediatric pharmacokinetics and safety trial 22 pediatric subjects 12 to 17 years of age with interdigital tinea pedis received naftifine hydrochloride gel. The incidence of adverse reactions in the pediatric population was similar to that observed in adult population. Cumulative irritancy testing revealed the potential for naftifine hydrochloride gel to cause irritation.

There was no evidence that naftifine hydrochloride gel causes contact sensitization, phototoxicity, or photoallergenicity in healthy skin.

Postmarketing Experience

Because these reactions 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. The following adverse reactions have been identified during post-approval use of naftifine hydrochloride: blisters, burning sensation, crusting, dryness, erythema/redness, inflammation, irritation, maceration, pain, pruritus /itching, rash and swelling.

Pregnancy Risk Summary There are no available data on naftifine hydrochloride gel use in pregnant women to evaluate a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. In animal reproduction studies, no adverse effects on embryofetal development were seen at oral doses administered during the period of organogenesis up to 37 times the maximum recommended human dose (MRHD) in pregnant rats or subcutaneous doses administered during the period of organogenesis up to 4 times the MRHD in pregnant rats or 7 times the MRHD in pregnant rabbits ( see Data ). All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown.

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Data Animal Data Systemic embryofetal development studies were conducted in rats and rabbits. For the comparison of animal to human doses, the MRHD is set at 4 g 2% gel per day (1.33 mg/kg/day for a 60 kg individual). Oral doses of 30 mg/kg/day, 100 mg/kg/day, and 300 mg/kg/day naftifine hydrochloride were administered during the period of organogenesis to pregnant female rats.

No treatment-related effects on embryofetal toxicity were noted at doses up to 300 mg/kg/day (37 times the MRHD based on mg/m 2 comparison). Subcutaneous doses of 10 mg/kg/day and 30 mg/kg/day naftifine hydrochloride were administered during the period of organogenesis to pregnant female rats. No treatment-related effects on embryofetal toxicity were noted at 30 mg/kg/day (4 times the MRHD based on mg/m 2 comparison). Subcutaneous doses of 3 mg/kg/day, 10 mg/kg/day, and 30 mg/kg/day naftifine hydrochloride were administered during the period of organogenesis to pregnant female rabbits. No treatment-related effects on embryofetal toxicity were noted at 30 mg/kg/day (7 times the MRHD based on mg/m 2 comparison). A peri- and post-natal development study was conducted in rats.

Oral doses of 30 mg/kg/day, 100 mg/kg/day, and 300 mg/kg/day naftifine hydrochloride were administered to female rats from gestational day 14 to lactation day 21. Reduced body weight gain of females during gestation and of the offspring during lactation was noted at 300 mg/kg/day (37 times the MRHD based on mg/m 2 comparison). No developmental toxicity was noted at 100 mg/kg/day (12 times the MRHD based on mg/m 2 comparison).

Pediatric Use The safety and effectiveness of naftifine hydrochloride gel have been established in the age group 12 to 18 years of age with interdigital tinea pedis. Use of naftifine hydrochloride gel in this age group is supported by evidence from adequate and well controlled trials in adults with additional safety and PK data from an open label trial, conducted in 22 adolescents ≥12 years of age who were exposed to naftifine hydrochloride gel at a dose of approximately 4 g/day . Safety and effectiveness in pediatric patients <12 years of age have not been established.