Ketoconazole dosage, side effects

Ketoconazole dosage, side effects:

Ketoconazole is an antifungal medication used to treat a variety of fungal infections. It belongs to the imidazole class of antifungals and works by inhibiting the synthesis of ergosterol, a critical component of fungal cell membranes, leading to cell death.

Brand Names

Ketoconazole is sold under various brand names worldwide, including:

1. Nizoral (most common brand name)
2. Ketodan
3. Ketozole
4. Extina (foam for topical use)
5. Xolegel (gel for topical use)
6. Kuric (cream for topical use)
7. Ketofungol
8. Fungarest
9. Ketomed

Forms and Uses

Ketoconazole is available in several formulations, depending on the type and location of the fungal infection:

1. Topical Forms:
   • Cream
   • Shampoo
   • Foam
   • Gel
   • Used for fungal skin infections, dandruff, seborrheic dermatitis, and pityriasis versicolor.
2. Oral Tablets:
   • Used for systemic fungal infections (e.g., blastomycosis, histoplasmosis, candidiasis).
   • Rarely used today due to the risk of severe side effects, including liver toxicity.
3. Vaginal Cream:
   • Used for vaginal yeast infections.

Mechanism of Action

Ketoconazole inhibits the enzyme lanosterol 14-α-demethylase, which is essential for converting lanosterol to ergosterol. Without ergosterol, the fungal cell membrane becomes leaky and dysfunctional, leading to cell death.

Indications

• Fungal skin infections (e.g., ringworm, athlete’s foot, jock itch)
• Seborrheic dermatitis
• Dandruff
• Pityriasis versicolor
• Systemic fungal infections (oral form, rarely used now)
• Vaginal yeast infections

Side Effects

1. Topical Use:
   • Mild irritation, burning, or itching at the application site.
2. Oral Use (more severe side effects):
   • Nausea, vomiting, abdominal pain
   • Liver toxicity (hepatitis, liver failure)
   • Hormonal imbalances (e.g., reduced cortisol, testosterone)
   • Adrenal insufficiency
   • Allergic reactions (rash, itching, swelling)

Contraindications

• Liver disease
• Hypersensitivity to ketoconazole or other azole antifungals
• Concurrent use with certain medications (e.g., statins, terfenadine, cisapride) due to risk of severe drug interactions.

Drug Interactions

Ketoconazole is a potent inhibitor of the CYP3A4 enzyme, which metabolizes many drugs. It can increase the levels of:

• Statins (risk of rhabdomyolysis)
• Calcium channel blockers
• Benzodiazepines
• Warfarin
• Immunosuppressants (e.g., cyclosporine, tacrolimus)

Precautions

• Liver function tests should be monitored during oral therapy.
• Avoid alcohol to reduce the risk of liver damage.
• Use with caution in patients with adrenal or pituitary gland disorders.

Current Status

• Oral ketoconazole is rarely used for systemic fungal infections due to its side effects and the availability of safer alternatives (e.g., fluconazole, itraconazole).
• Topical forms remain widely used for skin and scalp conditions.

If you have specific questions or need further details, feel free to ask!