5.1 Local Adverse Reactions

If irritation develops, discontinue treatment and institute appropriate therapy.

Physicians should exercise caution when prescribing ERTACZO cream, 2%, to patients known to be sensitive to azole antifungals since cross-reactivity may occur.

6.1 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 practice.

In clinical trials, cutaneous adverse events occurred in 7 of 297 (2%) subjects (2 of them severe) receiving ERTACZO cream, 2%, and in 7 of 291 (2%) subjects (2 of them severe) receiving vehicle. These reported cutaneous adverse events included contact dermatitis, dry skin, burning skin, and application site skin tenderness.

In a dermal sensitization trial, 8 of 202 evaluable subjects tested with ERTACZO cream, 2%, and 4 of 202 evaluable subjects tested with vehicle exhibited a erythematous reaction in the challenge phase. There was no evidence of cumulative irritation or contact sensitization in a repeated insult patch test involving 202 healthy volunteers.

6.2 Postmarketing Experience

The following adverse reactions have been identified during post-approval use of ERTACZO cream, 2%. 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.

Cutaneous adverse events:erythema, pruritus, vesiculation, desquamation, and hyperpigmentation.

8.1 Pregnancy

Risk Summary

There are no available data on ERTACZO cream, 2% use in pregnant women to evaluate for a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. In animal reproduction studies, there were no adverse developmental effects observed with oral administration of sertaconazole nitrate to pregnant rats and rabbits during organogenesis at doses 40 and 80 times, respectively, the maximum recommended human dose (MRHD) based on body surface area (BSA) comparison. In rats, when maternal dosing was continued until weaning, a reduction in live birth indices and an increase in the number of still-born pups was observed at doses 20 and 40 times the MRHD based on BSA comparison ( see Data).

The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of major birth defects, loss and other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.

Data

Animal Data

Animal embryofetal development studies have not been conducted with ERTACZO cream, 2%. Embryofetal development studies performed in pregnant rats and rabbits administered oral doses of sertaconzaole nitrate up to 160 mg/kg/day (40 times [rats] and 80 times [rabbits] the MRHD based on a BSA comparison) during the period of organogenesis revealed no malformations or embryofetal developmental toxicity. In a pre- and postnatal development study, pregnant rats were administered oral doses of sertaconazole nitrate from pregnancy day 6 to lactation day 20. A reduction in live birth indices and an increase in the number of still-born pups were seen at doses 20 and 40 times the MRHD based on BSA comparison.

8.2 Lactation

Risk Summary

There are no data available on the presence of sertaconazole in human or animal milk, its effects on the breastfed infant, or its effects on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for ERTACZO cream, 2% and any potential adverse effects on the breastfed infant from ERTACZO cream, 2% or from the underlying maternal condition.

8.4 Pediatric Use

The safety and effectiveness of ERTACZO cream, 2%, have not been established in pediatric patients younger than 12 years of age.

8.5 Geriatric Use

Clinical trials of ERTACZO cream, 2%, did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.

12.1 Mechanism of Action

Sertaconazole nitrate is an azole antifungal [see Clinical Pharmacology (12.4)] .

12.2 Pharmacokinetics

In a multiple-dose pharmacokinetic trial that included 5 male subjects with interdigital tinea pedis (range of diseased area, 42 - 140 cm 2; mean, 93 cm 2), ERTACZO cream, 2%, was topically applied every 12 hours for a total of 13 doses to the diseased skin (0.5 g sertaconazole nitrate per 100 cm 2). Sertaconazole concentrations in plasma measured by serial blood sampling for 72 hours after the thirteenth dose were below the limit of quantitation (2.5 ng/mL) of the analytical method used.

12.3 Microbiology

Mechanism of Action

Sertaconazole, an azole antifungal agent, inhibits fungal cytochrome P-450-mediated 14 alpha-lanosterol demethylase enzyme. This enzyme functions to convert lanosterol to ergosterol. Ergosterol is a key component of fungal cell membranes and lack of this component leads to fungal cell injury by leakage of key constituents in the cytoplasm from the cell.

Activity In Vitro and in Clinical Infections

Sertaconazole nitrate has been shown to be active against isolates of the following microorganisms in clinical infections [see Indications and Usage (1)] :

• Trichophyton rubrum
• Trichophyton mentagrophytes
• Epidermophyton floccosum

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

In a 2-year rat dermal carcinogenicity study, topical administration of sertaconazole nitrate cream did not increase the number of neoplastic lesions compared to control animals, at sertaconazole nitrate doses of up to 800 mg/kg/day (200 times the MRHD based on a BSA comparison).

No clastogenic potential was observed in a mouse micronucleus test. Sertaconazole nitrate was nonclastogenic in the in vivo mouse sister chromatid exchange assay. There was no evidence that sertaconazole nitrate induced unscheduled DNA synthesis in primary rat hepatocyte cultures.

Rats treated orally with up to 160 mg/kg/day of sertaconazole nitrate (40 times the MRHD based on a BSA comparison), exhibited no toxicity or adverse effects on reproductive performance or fertility in male or female rats.