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. |
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 | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for SPECTAZOLE (SPECTAZOLE).
| Breastfeeding | Unknown if econazole nitrate is excreted in human milk following topical application. Systemic absorption is minimal. Caution should be exercised when administered to a nursing woman. M/P ratio: not available. |
| 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. |
■ FDA Black Box Warning
None
| Serious Effects |
["Hypersensitivity to econazole 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"] |
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| 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. |