Ketoconazole

Generic Name: Ketoconazole
Common Brand Names: Nizoral, Extina, Xolegel

Introduction

Ketoconazole is an antifungal medication used to treat a variety of fungal infections, including those of the skin, nails, and systemic infections. It works by inhibiting the synthesis of ergosterol, a vital component of fungal cell membranes.

Conditions of Use (Indications)

  1. Fungal Infections: Treatment of dermatophyte infections, candidiasis, and systemic fungal infections.
  2. Seborrheic Dermatitis: Used topically for managing seborrheic dermatitis and dandruff.
  3. Cushing’s Syndrome: Off-label use in managing endogenous Cushing’s syndrome by inhibiting cortisol synthesis.

Mechanism of Action

Ketoconazole inhibits the enzyme 14α-demethylase, which is involved in the synthesis of ergosterol, a critical component of the fungal cell membrane. By disrupting cell membrane integrity, ketoconazole prevents fungal cell growth and replication.

Side Effects

1. Common:

  • Skin irritation, particularly when used topically.
  • Nausea and abdominal discomfort.
  • Headache and dizziness.

2. Serious:

  • Hepatotoxicity (liver damage), which can be severe.
  • QT interval prolongation and arrhythmias.
  • Adrenal insufficiency (due to inhibition of cortisol synthesis).

Harmful Interactions

  1. CYP3A4 Inhibitors: Ketoconazole can interact with other drugs metabolized by CYP3A4, increasing their concentrations (e.g., statins, cyclosporine).
  2. Anticoagulants: Increases the effects of warfarin, leading to an increased risk of bleeding.
  3. Rifampin: Rifampin induces liver enzymes and can reduce ketoconazole’s effectiveness.

Contraindications

  1. Known hypersensitivity to ketoconazole or any of its components.
  2. Liver disease or elevated liver enzymes.
  3. Concomitant use with drugs that prolong the QT interval (e.g., quinidine, cisapride).

Latest References

  1. Paul, M., et al. (2023). “Ketoconazole in Fungal Infections: A Review of Current Therapeutic Options.” Journal of Antimicrobial Chemotherapy, DOI: 10.1093/jac/dkz347.
  2. PubMed Central. (2022). “Ketoconazole and its Role in the Management of Cushing’s Syndrome.” Endocrine Reviews.