Ketoconazole

Provider Level

RN/Paramedic

Class

Azole Antifungal

Mechanism of Action

Inhibits the synthesis of ergosterol, a vital component of fungal cell membranes, altering cellular permeability and resulting in fungal cell death or fungistatic activity.

Indications

Treatment of susceptible systemic and superficial fungal infections, such as candidiasis, dermatophytosis, and tinea infections. Note: rarely utilized in the acute prehospital setting.

Contraindications

Known hypersensitivity, concurrent use of medications that prolong the QT interval and are metabolized by CYP3A4, and acute or chronic liver disease.

Routes

PO, Dermal

Onset / Duration

Onset: Variable (hours to days depending on infection). Duration: Varies with half-life and administration schedule.

Adverse Effects

Nausea, vomiting, abdominal pain, severe hepatotoxicity, QT interval prolongation, rash, pruritus, and endocrine dysfunction (e.g., gynecomastia).

Precautions & Interactions

Carries a black box warning for severe hepatotoxicity and QT prolongation leading to Torsades de Pointes. Highly interactive with numerous medications due to strong CYP3A4 inhibition.

Special Considerations

Not a standard EMS or prehospital emergency medication. Providers (RN/Paramedic) should primarily be aware of it when reviewing a patient's home medication list to identify potential severe drug-drug interactions or causes of acute hepatic or cardiac events.