MENTAX
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MENTAX (MENTAX).
Inhibits fungal squalene epoxidase, thereby blocking ergosterol biosynthesis and causing accumulation of squalene, leading to fungal cell death.
| Metabolism | Minimal systemic absorption; metabolized primarily via hepatic pathways (CYP450 enzymes) if absorbed, but extensive first-pass metabolism. |
| Excretion | Primarily fecal (biliary) as unchanged drug and metabolites; renal excretion of metabolites accounts for less than 1% of the dose. |
| Half-life | Terminal elimination half-life is approximately 5-6 hours; clinical significance: supports twice-daily dosing for topical antifungal therapy. |
| Protein binding | Greater than 99% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Systemic Vd not clinically relevant due to minimal absorption; in animal studies, Vd is approximately 0.5 L/kg. |
| Bioavailability | Topical: negligible systemic absorption (less than 5% of applied dose). |
| Onset of Action | Topical: clinical improvement observed within 1-2 weeks of regular application. |
| Duration of Action | Topical: residual antifungal activity persists for 24-48 hours after application; treatment typically continues for 4-6 weeks. |
| Molecular Weight | 317.47 |
Butenafine hydrochloride 1% cream: apply to affected area once daily for 2 weeks for tinea pedis; for tinea corporis and tinea cruris, apply once daily for 1 week.
| Dosage form | CREAM |
| Renal impairment | No dosage adjustment required for renal impairment. Butenafine is minimally absorbed systemically and undergoes negligible renal excretion. |
| Liver impairment | No dosage adjustment required for hepatic impairment. Systemic absorption is minimal; no studies in Child-Pugh classes; expected to be safe. |
| Pediatric use | Children 2 years and older: apply butenafine 1% cream once daily for 2 weeks for tinea pedis; for tinea corporis/cruris, apply once daily for 1 week. Safety and efficacy in children under 2 years not established. |
| Geriatric use | No specific dosage adjustment needed; use standard adult dosing. Apply to affected area once daily as directed. |
| 1st trimester | Limited data; use only if clearly needed. Topical application has minimal systemic absorption. |
| 2nd trimester | No known risks from topical use; systemic absorption is negligible. |
| 3rd trimester | No known risks from topical use; systemic absorption is negligible. |
Clinical note
Comprehensive clinical and safety monograph for MENTAX (MENTAX).
| Placental transfer | No data available; however, topical butenafine has negligible systemic absorption, making significant placental transfer unlikely. |
| Breastfeeding | Minimal systemic absorption with topical use; unlikely to be excreted into breast milk in clinically significant amounts. Caution if applied to breast area to avoid infant ingestion. |
| Lactation Rating |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to butenafine or any component of the formulation
| Precautions | For external use only, Avoid contact with eyes, nose, mouth, or other mucous membranes, Discontinue if irritation or sensitivity develops, Not for ophthalmic, oral, or intravaginal use |
| Food/Dietary | No known food interactions. No dietary restrictions required. Avoid alcohol if concurrent systemic antifungal therapy, but not specific to MENTAX. |
| Clinical Pearls | MENTAX (butenafine hydrochloride) is a benzylamine antifungal. It is fungicidal against dermatophytes and effective in tinea pedis, tinea cruris, and tinea corporis. It has higher lipophilicity than allylamines, allowing once-daily dosing. Reserve for uncomplicated cases; not for nail or scalp infections. Avoid in patients with hypersensitivity to benzylamines. |
Loading safety data…
| L3 (Moderately Safe) |
| Teratogenic Risk | Teratogenic risk cannot be excluded based on animal studies; no adequate human data. First trimester: use only if benefit outweighs risk. Second and third trimesters: limited data, avoid if possible. |
| Fetal Monitoring | Monitor for signs of hypersensitivity, injection site reactions; no specific fetal monitoring required. |
| Fertility Effects | No known effects on fertility in animal studies; no human data. |
| Patient Advice | Apply to clean, dry affected area and surrounding skin once daily for 2 to 4 weeks. · Wash hands before and after application. · Do not cover with occlusive dressings unless directed by your doctor. · Avoid contact with eyes, nose, mouth, or open wounds. · Complete full course even if symptoms improve to prevent recurrence. · Notify your doctor if irritation or no improvement after 4 weeks. |