What it's for (Indications)
- Ketoconazole topical is indicated for the treatment of tinea infections (e.
- g.
- , tinea corporis, tinea cruris, tinea pedis, tinea versicolor), cutaneous candidiasis (fungal infection caused by Candida), seborrhoeic dermatitis (inflammation of the skin), candida vulvitis (inflammation of the vulva), and seborrhea (red, itchy and white scales).
Dosage Information
| Type | Guideline |
|---|---|
| Standard | Dosage information provided pertains to *oral* ketoconazole tablets, not topical formulations. For systemic infections, the usual duration of therapy for oral ketoconazole is 6 months, continued until active fungal infection has subsided. The recommended starting dose for adults is a single daily administration of 200 mg. If clinical responsiveness is insufficient, the dose may be increased to 400 mg once daily. For children over 2 years of age, a single daily dose of 3.3 to 6.6 mg/kg has been used, though ketoconazole tablets have not been studied in children under 2 years of age. For topical ketoconazole, dosage and administration typically involve applying the cream or shampoo to the affected area once or twice daily, as directed by a healthcare professional; specific instructions vary by product and concentration, and are not provided in the merged data. |
Safety & Warnings
Common Side Effects
- Common local side effects associated with topical ketoconazole may include stinging, swelling, irritation, or redness of the treated skin.
- Systemic adverse reactions such as anaphylactoid reaction, gynecomastia, alcohol intolerance, anorexia, hyperlipidemia, increased appetite, insomnia, nervousness, headache, dizziness, paresthesia, somnolence, photophobia, orthostatic hypotension, epistaxis, vomiting, diarrhea, nausea, constipation, abdominal pain, dry mouth, dyspepsia, flatulence, tongue discoloration, hepatitis, and jaundice have been reported with *oral* ketoconazole and are generally not expected with topical application due to minimal systemic absorption.
Serious Warnings
- Black Box Warning: WARNING: Because *oral* ketoconazole tablets have been associated with serious adverse reactions, including severe hepatotoxicity (with cases of fatal outcome) and drug interactions, ketoconazole tablets are not indicated for treatment of onychomycosis, cutaneous dermatophyte infections, or Candida infections unless other effective antifungal therapy is not available or tolerated and the potential benefits are considered to outweigh the potential risks. This boxed warning specifically applies to the *oral* formulation of ketoconazole.
- Caution should be exercised in patients with known allergies to azole antifungals.
- For pregnancy, no definitive data regarding topical ketoconazole is available; therefore, caution is advised, and a healthcare provider should be consulted for a risk/benefit assessment.
- The effects of topical ketoconazole are undetermined in nursing females; consultation with a healthcare provider is recommended for further details.
- It is critical to note that *oral* ketoconazole has been associated with serious adverse reactions, including significant hepatotoxicity (potentially fatal) and should only be used when other effective antifungal therapy is not available or tolerated, and potential benefits outweigh potential risks.
- These severe warnings predominantly apply to the oral formulation due to systemic absorption and are generally not applicable to topical ketoconazole under normal use, although systemic absorption is possible, especially with extensive use on compromised skin.
How it Works (Mechanism of Action)
Ketoconazole blocks the synthesis of ergosterol, a key component of the fungal cell membrane, through the inhibition of cytochrome P-450 dependent enzyme lanosterol 14α-demethylase. This enzyme is responsible for the conversion of lanosterol to ergosterol in the fungal cell membrane. The inhibition leads to an accumulation of methylated sterol precursors and a depletion of ergosterol within the cell membrane, thereby weakening the structure and function of the fungal cell membrane, which is essential for fungal growth and survival.