Butenafine (Monograph)

Brand names: Lotrimin Ultra, Mentax
Drug class: Benzylamines
ATC class: D01AE23
VA class: DE102
Chemical name: N- (4-(1,1-dimethylethyl)phenyl)methyl)-N-methyl-1-naphthalenemethanamine hydrochloride
Molecular formula: C₂₃H₂₇N•ClH
CAS number: 101827-46-7

Introduction

Antifungal; benzylamine.

Uses for Butenafine

Dermatophytoses

Treatment of tinea corporis (body ringworm) and tinea cruris (jock itch) caused by Epidermophyton floccosum, Trichophyton mentagrophytes, T. rubrum, or T. tonsurans.

Treatment of tinea pedis (athlete’s foot) caused by E. floccosum, T. mentagrophytes, T. rubrum, or T. tonsurans.

Available for self-medication (OTC use) for treatment of tinea corporis, tinea cruris, and tinea pedis.

Do not use for scalp or nail infections.

Has not been evaluated in immunocompromised patients.

Topical antifungals usually effective for treatment of uncomplicated tinea corporis or tinea cruris. An oral antifungal may be necessary when tinea corporis or tinea cruris is extensive, dermatophyte folliculitis is present, infection is chronic or does not respond to topical therapy, or patient is immunocompromised because of coexisting disease or concomitant therapy.

Topical antifungals usually effective for treatment of uncomplicated tinea pedis. An oral antifungal may be necessary for treatment of hyperkeratotic areas on palms and soles, for chronic moccasin-type tinea pedis, and for tinea unguium (fingernail or toenail dermatophyte infections, onychomycosis).

Pityriasis (Tinea) Versicolor

Treatment of pityriasis (tinea) versicolor caused by Malassezia furfur (Pityrosporum orbiculare or P. ovale).

Has not been evaluated in immunocompromised patients.

Topical antifungals generally effective; an oral antifungal (with or without a topical antifungal) may be necessary in patients who have extensive or severe infections or have failed to respond to or have frequent relapses with topical therapy.

Related/similar drugs

clotrimazole topical, ketoconazole topical, terbinafine, miconazole topical, Lamisil

Butenafine Dosage and Administration

Administration

Topical Administration

Apply topically to the skin as a 1% cream.

Avoid contact with eyes, nose, mouth, and other mucous membranes.

Clean affected areas with soap and water; dry thoroughly prior to applying cream. May be applied after bathing.

Massage cream gently into affected areas. Wash hands after application process.

Do not use occlusive dressings or wrappings.

When treating tinea pedis, pay special attention to spaces between toes. Also, wear well-fitting, ventilated shoes and change shoes and socks at least once daily.

Dosage

Pediatric Patients

Dermatophytoses

Tinea Corporis or Tinea Cruris

Topical

Children ≥12 years of age: Apply to affected area and immediately surrounding skin once daily for 2 weeks.

If clinical improvement does not occur after treatment, diagnosis and therapy should be reevaluated.

Tinea Pedis

Topical

Children ≥12 years of age: Apply to affected area and immediately surrounding skin twice daily (morning and night) for 7 days or once daily for 4 weeks.

Some data indicate the 7-day regimen is less effective than the 4-week regimen; this should be considered when selecting dosage regimen for patients at risk for developing bacterial cellulitis of lower extremities associated with interdigital cracking/fissuring.

If clinical improvement does not occur after treatment, diagnosis and therapy should be reevaluated.

Pityriasis (Tinea) Versicolor

Topical

Children ≥12 years of age: Apply to affected area and immediately surrounding skin once daily for 2 weeks.

If clinical improvement does not occur after treatment, diagnosis and therapy should be reevaluated.

Adults

Dermatophytoses

Tinea Corporis or Tinea Cruris

Topical

Apply to affected area and immediately surrounding skin once daily for 2 weeks.

If clinical improvement does not occur after treatment, diagnosis and therapy should be reevaluated.

Tinea Pedis

Topical

Apply to affected area and immediately surrounding skin twice daily (morning and night) for 7 days or once daily for 4 weeks.

Some data indicate the 7-day regimen is less effective than the 4-week regimen; this should be considered when selecting dosage regimen for patients at risk for developing bacterial cellulitis of lower extremities associated with interdigital cracking/fissuring.

If clinical improvement does not occur after treatment, diagnosis and therapy should be reevaluated.

Pityriasis (Tinea) Versicolor

Topical

Apply to affected area and immediately surrounding skin once daily for 2 weeks.

If clinical improvement does not occur, diagnosis and therapy should be reevaluated.

Special Populations

No special population dosage recommendations at this time.

Cautions for Butenafine

Contraindications

• Known hypersensitivity to butenafine or any ingredient in the formulation.

Warnings/Precautions

Warnings

Administration Precautions

For external use only. Use only for topical application to the skin; not for ophthalmic or intravaginal use.

Avoid contact with eyes, nose, mouth, and other mucous membranes.

If contact with the eye(s) occurs, wash with large amounts of water; consult a clinician if ocular irritation persists.

Do not use for scalp or nail infections.

Sensitivity Reactions

If irritation or sensitivity occurs, discontinue drug and initiate appropriate therapy.

Contact dermatitis has been reported rarely.

Use with caution in patients hypersensitive to allylamine antifungals (e.g., naftifine, terbinafine) since cross-sensitivity may occur.

General Precautions

Selection and Use of Antifungals

Prior to use, confirm diagnosis by direct microscopic examination of scrapings from infected tissue mounted in potassium hydroxide (KOH) or by culture.

Specific Populations

Pregnancy

Category B.

Lactation

Not known whether distributed into milk following topical application. Use with caution and avoid applying to the breast of nursing women.

Pediatric Use

Safety and efficacy not established in children <12 years of age.

Common Adverse Effects

Burning/stinging, itching, worsening of condition.

Drug Interactions

No formal drug interaction studies to date.

Butenafine Pharmacokinetics

Absorption

Percutaneous absorption occurs following topical application of 1% cream. Total amount of dose absorbed into systemic circulation following topical application has not been quantified.

Distribution

Not known whether distributed into milk following topical application.

Elimination

Metabolism

Systemically absorbed drug is metabolized; principal metabolite in urine is formed through hydroxylation at the terminal t-butyl side-chain.

Half-life

After absorption through skin, a biphasic decline occurs with estimated half-lives of 35 and >150 hours, respectively.

Stability

Storage

Topical

Cream

5–30°C.

Actions and Spectrum

• Benzylamine antifungal structurally and pharmacologically related to allylamine antifungals (e.g., naftifine, terbinafine).

• May be fungicidal in certain concentrations or against susceptible organisms (e.g., dermatophytes).

• Presumably exerts its antifungal activity by altering cellular membranes, resulting in increased membrane permeability, and growth inhibition.

• Appears to interfere with sterol biosynthesis by inhibiting the enzyme squalene monooxygenase (squalene 2,3-epoxidase), which results in decreased amounts of sterols, especially ergosterol, and a corresponding accumulation of squalene (the usual substrate of the enzyme) in the cells.

• Dermatophytes: Active in vitro against Epidermophyton floccosum, Microsporum canis, Trichophyton mentagrophytes, T. rubrum, and T. tonsurans.

• Other fungi: Active in vitro against Malassezia furfur. Also active in vitro against Candida albicans and C. parapsilosis.

Advice to Patients

• Importance of completing full course of treatment, even if symptoms improve.

• Importance of contacting clinician if improvement does not occur by end of prescribed treatment period.

• Importance of notifying clinician if condition worsens or treated area shows signs of increased irritation, redness, itching, burning, blistering, swelling, or oozing.

• Importance of applying to affected areas as directed and avoiding contact with eyes, nose, mouth, or other mucous membranes.

• Advise patients to wash their hands after touching the affected areas so that the infection is not spread to other areas of the body or to other individuals.

• For patients with tinea pedis (athlete’s foot), importance of wearing well-fitting, ventilated shoes and changing socks at least once daily.

• Importance of not using occlusive dressings, unless otherwise directed by clinician.

• Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs.

• Importance of women informing their clinician if they are or plan to become pregnant or plan to breast-feed.

• Importance of informing patients of other important precautionary information. (See Cautions.)

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

Reload page with references included

Medical Disclaimer