Naftin Cream is an allylamine antifungal indicated for the treatment of interdigital tinea pedis, tinea cruris, and tinea corporis caused by the organism Trichophyton rubrum.
Naftin Dosage and Administration
For topical use only. Naftin Cream is not for ophthalmic, oral or intravaginal use. Apply a thin layer of Naftin Cream once-daily to the affected areas plus a ½ inch margin of healthy surrounding skin for 2 weeks.
Warnings and Precautions
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.
During clinical trials, 760 subjects were exposed to naftifine 1% and 2% cream formulations. A total of 421 subjects with interdigital tinea pedis and/or tinea cruris were treated with Naftin Cream.
In two randomized, vehicle-controlled trials (400 patients were treated with Naftin Cream). The population was 12 to 88 years old, primarily male (79%), 48% Caucasian, 36% Black or African American, 40% Hispanic or Latino and had either predominantly interdigital tinea pedis or tinea cruris. Most subjects received doses once-daily, topically, for 2 weeks to cover the affected skin areas plus a ½ inch margin of surrounding healthy skin. In the two vehicle-controlled trials, 17.5% of Naftin Cream treated subjects experienced an adverse reaction compared with 19.3% of vehicle subjects. The most common adverse reaction (≥1%) is pruritus. Most adverse reactions were mild in severity. The incidence of Adverse Reactions in the Naftin Cream treated population were not significantly different than the vehicle treated population.
In an open-label pediatric pharmacokinetics and safety trial, 22 pediatric subjects 13-17 years of age with interdigital tinea pedis and tinea cruris received Naftin Cream. The incidence of adverse reactions in the pediatric population was similar to that observed in the adult population.
The following adverse reactions have been identified during post-approval use of (naftifine hydrochloride): redness/irritation, inflammation, maceration, swelling, burning, blisters, serous drainage, crusting, headache, dizziness, leukopenia, agranulocytosis. 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.
USE IN SPECIFIC POPULATIONS
Pregnancy Category B. There are no adequate and well-controlled studies of Naftin Cream in pregnant women. Because animal reproduction studies are not always predictive of human response, Naftin Cream should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
The animal multiples of human exposure calculations were based on daily dose body surface area comparison (mg/m2) for the reproductive toxicology studies described in this section and in Section 13.1. The Maximum Recommended Human Dose (MRHD) was set at 8 g 2% cream per day (2.67 mg/kg/day for a 60 kg individual).
Systemic embryofetal development studies were conducted in rats and rabbits. Oral doses of 30, 100 and 300 mg/kg/day naftifine hydrochloride were administered during the period of organogenesis (gestational days 6 – 15) to pregnant female rats. No treatment-related effects on embryofetal toxicity or teratogenicity were noted at doses up to 300 mg/kg/day (18.2× MRHD). Subcutaneous doses of 10 and 30 mg/kg/day naftifine hydrochloride were administered during the period of organogenesis (gestational days 6 – 15) to pregnant female rats. No treatment-related effects on embryofetal toxicity or teratogenicity were noted at 30 mg/kg/day (1.8× MRHD). Subcutaneous doses of 3, 10 and 30 mg/kg/day naftifine hydrochloride were administered during the period of organogenesis (gestational days 6 – 18) to pregnant female rabbits. No treatment related effects on embryofetal toxicity or teratogenicity were noted at 30 mg/kg/day (3.6× MRHD).
A peri- and post-natal development study was conducted in rats. Oral doses of 30, 100 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 (18.2× MRHD). No developmental toxicity was noted at 100 mg/kg/day (6.1× MRHD).
It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Naftin Cream is administered to a nursing woman.
The safety and effectiveness of Naftin Cream have been established in the age group 12-17 with interdigital tinea pedis and tinea cruris.
Use of Naftin Cream in this age group is supported by evidence from adequate and well controlled studies 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 Naftin Cream at a dose of approximately 8 g/day [see Clinical Pharmacology (12.3)].
Safety and effectiveness in pediatric patients < 12 years of age have not been established.
Naftin Cream is a white to off-white cream for topical use only. Each gram of (naftifine hydrochloride) Cream contains 20 mg of naftifine hydrochloride, a synthetic allylamine antifungal compound.
Chemically, naftifine HCl is (E)-N-Cinnamyl-N-methyl-1-napthalenemethylamine hydrochloride.
The molecular formula is C21H21N•HCl with a molecular weight of 323.86.
The structural formula of naftifine hydrochloride is:
Naftin Cream contains the following inactive ingredients: benzyl alcohol, cetyl alcohol, cetyl esters wax, isopropyl myristate, polysorbate 60, purified water, sodium hydroxide, sorbitan monostearate, stearyl alcohol, and hydrochloric acid.
Naftin - Clinical Pharmacology
Mechanism of Action
Naftin Cream is a topical antifungal drug [see Clinical Pharmacology(12.4)]
In vitro and in vivo bioavailability studies have demonstrated that naftifine penetrates the stratum corneum in sufficient concentration to inhibit the growth of dermatophytes.
The pharmacokinetics of Naftin Cream was evaluated following once-daily topical application for 2 weeks to twenty one adult subjects, both males and females, with both tinea pedis and tinea cruris. The median total amount of cream applied was 6.4 g (range 5.3-7.5 g) per day. The results showed that the systemic exposure (i.e., maximum concentration (Cmax) and area under the curve (AUC)) to naftifine increased over the 2 week treatment period in all the 21 subjects. Geometric Mean (CV%) AUC0-24 was 117 (41.2) ng*hr/mL on Day 1, and 204 (28.5) ng*hr/mL on Day 14. Geometric Mean (CV %) Cmax was 7 ng/mL (55.6) on Day 1 and 11 ng/mL (29.3) on day 14. Median Tmax was 8.0 hours on Day 1 (range: 4 to 24) and 6.0 hours on Day 14 (range: 0 to 16). Accumulation after 14 days of topical application was less than two fold. Trough concentrations generally increased throughout the 14 day study period. Naftifine continued to be detected in plasma in 13/21 (62%) subjects on day 28, the mean (SD) plasma concentrations were 1.6 ± 0.5 ng/mL (range below limit of quantitation (BLQ) to 3 ng/mL).
In the same pharmacokinetic trial conducted in patients with tinea pedis and tinea cruris, median fraction of the dose excreted in urine during the treatment period was 0.0016% on Day 1 versus 0.0020% on Day 14.
In a second trial, that enrolled 22 subjects the pharmacokinetics of Naftin Cream was evaluated in 20 pediatric subjects 13 – 17 years of age with both tinea pedis and tinea cruris. Subjects were treated with a median dose of 8.1 g (range 6.6-10.1 g) applied to the affected areas once daily for 14 days. The results showed that the systemic exposure increased over the treatment period. Geometric Mean (CV%) AUC0-24 was 138 (50.2) ng*hr/mL on Day 1, and 192 (74.9) ng*hr/mL on Day 14. Geometric Mean (CV %) Cmax was 9.21 ng/mL (48.4) on Day 1 and 12.7 ng/mL (67.2) on day 14. Median fraction of the dose excreted in urine during the treatment period was 0.0030% on Day 1 and 0.0033% on Day 14.
Although the exact mechanism of action against fungi is not known, naftifine hydrochloride appears to interfere with sterol biosynthesis by inhibiting the enzyme squalene 2, 3-epoxidase.This inhibition of enzyme activity results in decreased amounts of sterols, especially ergosterol, and a corresponding accumulation of squalene in the cells.
Mechanism of Resistance
To date, a mechanism of resistance to naftifine has not been identified.
Naftifine has been shown to be active against most isolates of the following fungi, both in vitro and in clinical infections, as described in the INDICATIONS AND USAGE section:
- Trichophyton rubrum
Carcinogenesis, Mutagenesis, Impairment of Fertility
Long-term studies to evaluate the carcinogenic potential of Naftin Cream have not been performed.
Naftifine hydrochloride revealed no evidence of mutagenic or clastogenic potential based on the results of two in vitro genotoxicity tests (Ames assay and Chinese hamster ovary cell chromosome aberration assay) and one in vivo genotoxicity test (mouse bone marrow micronucleus assay).
Oral administration of naftifine hydrochloride to rats, throughout mating, gestation, parturition and lactation, demonstrated no effects on growth, fertility or reproduction, at doses up to 100 mg/kg/day (6.1× MRHD).
Naftin Cream has been investigated for safety and efficacy in a randomized, double-blind, vehicle-controlled, multi-center study in 146 subjects with symptomatic and dermatophyte culture positive tinea cruris. Subjects were randomized to receive (naftifine hydrochloride) Cream or vehicle. Subjects applied the study agent (naftifine hydrochloride) Cream or vehicle to the affected area plus a ½-inch margin of healthy skin surrounding the affected area once-daily for 2 weeks. Signs and symptoms of tinea cruris (presence or absence of erythema, pruritus, and scaling) were assessed, and KOH examination and dermatophyte culture were performed at the primary efficacy endpoint at week 4.
The mean age of the study population was 47 years and 87% were male and 43% were white. At baseline, subjects were confirmed to have signs and symptoms of tinea cruris, positive KOH exam, and confirmed dermatophyte presence based on culture results from a central mycology laboratory. The analysis of the intent-to-treat population was a comparison of the proportions of subjects with a complete cure at the week 4 visit (see Table 1). Complete cure was defined as both clinical cure (absence of erythema, pruritus, and scaling) and mycological cure (negative KOH and dermatophyte culture).
The percentage of subjects experiencing clinical cure and the percentage of subjects experiencing mycological cure at week 4 are presented individually in Table 1 below.
|Endpoint||Naftin (naftifine hydrochloride) Cream, 2%
|Effective Treatment †||45(60%)||7(10%)|
Interdigital Tinea Pedis
Naftin Cream has been investigated for efficacy in a randomized, double-blind, vehicle-controlled, multi-center study in 217 subjects with symptomatic and dermatophyte culture positive interdigital tinea pedis. Subjects were randomized to receive Naftin Cream or vehicle. Subjects applied the study agent (naftifine hydrochloride) Cream or vehicle to the affected area of the foot plus a ½-inch margin of healthy skin surrounding the affected area once-daily for 2 weeks. Signs and symptoms of interdigital tinea pedis (presence or absence of erythema, pruritus, and scaling) were assessed and KOH examination and dermatophyte culture was performed at the primary efficacy endpoint at week 6.
The mean age of the study population was 42 years and 71% were male and 57% were white. At baseline, subjects were confirmed to have signs and symptoms of interdigital tinea pedis, positive KOH exam, and confirmed dermatophyte culture. The primary efficacy endpoint was the proportions of subjects with a complete cure at the week 6 visit (see Table 2). Complete cure was defined as both a clinical cure (absence of erythema, pruritus, and scaling) and mycological cure (negative KOH and dermatophyte culture).
The efficacy results at week 6, four weeks following the end of treatment, are presented in Table 2 below. Naftin Cream demonstrated complete cure in subjects with interdigital tinea pedis, but complete cure in subjects with only moccasin type tinea pedis was not demonstrated.
|Endpoint||Naftin (naftifine hydrochloride) Cream, 2%
How Supplied/Storage and Handling
Naftin Cream is a white to off-white cream supplied in collapsible tubes in the following sizes:
30g – NDC 0259-1102-30
45g – NDC 0259-1102-45
60g – NDC 0259-1102-60
Store Naftin Cream at 25°C (77°F); excursions permitted to 15-30°C (59-86°F) [see USP Controlled Room Temperature].
Patient Counseling Information
- Inform patients that Naftin Cream is for topical use only. Naftin Cream is not intended for oral, intravaginal or ophthalmic use.
- If irritation or sensitivity develops with the use of Naftin Cream treatment should be discontinued and appropriate therapy instituted. Patients should be directed to contact their physician if these conditions develop following use of Naftin Cream.
Naftin (naftifine hydrochloride) Cream, 2% is manufactured for Merz Pharmaceuticals, LLC, Greensboro, NC 27410
Naftin (naftifine hydrochloride) Cream, 2% is a registered trademark of Merz Pharmaceuticals, LLC
PRINCIPAL DISPLAY PANEL - 45 g Tube Carton
(Naftifine Hydrochloride) Cream, 2%
For Topical Use Only
Not for Ophthalmic Use, Oral or Intravaginal Use
naftifine hydrochloride cream
|Labeler - Merz Pharmaceuticals, LLC (126209282)|