SPECTAZOLE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for SPECTAZOLE (SPECTAZOLE).
Econazole nitrate, an imidazole antifungal, inhibits fungal cytochrome P450 14α-demethylase, disrupting ergosterol synthesis and increasing cell membrane permeability.
| Metabolism | Minimal systemic absorption following topical application; absorbed fraction is extensively metabolized in the liver via oxidation and glucuronidation. |
| Excretion | Primarily renal: approximately 70% of an oral dose is excreted unchanged in urine; biliary/fecal excretion accounts for ~20%, with the remainder as metabolites. |
| Half-life | Terminal elimination half-life is approximately 24-30 hours in patients with normal renal function, allowing once-daily dosing. |
| Protein binding | Approximately 98-99% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Volume of distribution is about 10-20 L/kg, indicating extensive tissue distribution and high tissue concentration relative to plasma. |
| Bioavailability | Topical: minimal systemic absorption (<1% of applied dose); oral formulation not available in the US; intravenous bioavailability is 100% by definition. |
| Onset of Action | Topical: clinical improvement typically noted within 2-3 days of twice-daily application for dermatophyte infections. |
| Duration of Action | Topical: sustained antifungal activity for up to 24 hours following a single application, supporting twice-daily dosing. |
| Molecular Weight | 387.9 |
Apply a thin layer to affected area once daily for 4-4 weeks; duration depends on indication.
| Dosage form | CREAM |
| Renal impairment | No adjustment required; negligible systemic absorption after topical application. |
| Liver impairment | No adjustment required; negligible systemic absorption after topical application. |
| Pediatric use | Safety and efficacy established; same dosing as adults for children ≥2 years; for children <2 years, use only under medical advice. |
| Geriatric use | No specific adjustments; same as adult dosing. |
| 1st trimester | Limited human data; animal studies show no teratogenicity at topical doses. Systemic absorption minimal. |
| 2nd trimester | No evidence of fetal harm; avoid large areas or prolonged use. |
| 3rd trimester | Considered safe for topical use; avoid near term due to theoretical risk of kernicterus (benzyl alcohol in formulation). |
Clinical note
Comprehensive clinical and safety monograph for SPECTAZOLE (SPECTAZOLE).
| Placental transfer | Negligible systemic absorption after topical application; minimal transfer expected. Specific placental transfer data not available. |
| Breastfeeding | Systemic absorption after topical application is negligible (<0.5%). Avoid application to breast area to prevent infant ingestion. Compatible with breastfeeding based on minimal excretion. |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to econazole nitrate, imidazoles, or any component of the formulation.
| Precautions | For external use only; avoid contact with eyes, If irritation or sensitization occurs, discontinue use, Not for ophthalmic or intravaginal use, Use caution in patients with hypersensitivity to imidazoles |
| Food/Dietary | No significant food interactions due to negligible systemic absorption. No dietary restrictions necessary. |
| Clinical Pearls | Spectazole (econazole nitrate) is a broad-spectrum imidazole antifungal used topically. It is effective against dermatophytes, Candida species, and some Gram-positive bacteria. Due to its low systemic absorption, it is safe for use in pregnancy (category C) but should be avoided on large areas or broken skin. For tinea pedis, treatment for 4 weeks is often required. Avoid occlusive dressings unless directed. Economical generic formulations are available. |
Loading safety data…
| Lactation Rating |
| L2 (Safer) |
| Teratogenic Risk | Pregnancy Category C. No adequate studies in pregnant women. In animal studies, econazole nitrate administered orally at doses 10-20 times the human dermal dose produced embryotoxicity and fetal resorption. However, topical application is not expected to result in significant systemic absorption. Risk to fetus cannot be ruled out. First trimester: avoid unless clearly needed. Second and third trimesters: use only if potential benefit justifies potential risk. |
| Fetal Monitoring | No specific fetal monitoring required. If used on large areas or under occlusive dressings, monitor for maternal systemic adverse effects (e.g., irritation, hypersensitivity). |
| Fertility Effects | No studies on fertility effects in humans. Animal studies with oral econazole showed impaired fertility at high doses. Topical use is unlikely to affect fertility due to minimal systemic absorption. |
| Patient Advice | Apply a thin layer to the affected area and gently rub in. · Wash hands before and after application unless treating hands. · Do not use in eyes, mouth, or vagina (vaginal formulation is different). · Continue use for the full prescribed duration even if symptoms improve. · Notify your doctor if irritation or allergic reaction occurs. |