Active Ingredient Details

Nizoral contains the active ingredient ketoconazole, which is classified as an antifungal medication. It works by disrupting the cell membrane of fungi, inhibiting their growth and proliferation. Ketoconazole is a broad-spectrum antifungal, effective against various yeast and dermatophyte infections.

Formulations and Strengths

Nizoral is available in several formulations, including cream, shampoo, and oral tablets. The cream is typically available in a 2% concentration, designed for topical application. The shampoo, also at a 2% concentration, is intended for use on the scalp. Oral tablets are usually provided in a 200 mg strength, and their use should be guided by a healthcare professional.

Therapeutic Indications

Nizoral is indicated for the treatment and management of fungal infections caused by various dermatophytes and yeasts. These include conditions such as tinea corporis (ringworm), tinea cruris (jock itch), tinea pedis (athlete’s foot), and seborrheic dermatitis. It is also used for systemic fungal infections in its oral form, such as candidiasis and blastomycosis.

Dosage and Administration

The dosage of Nizoral varies depending on the formulation and condition being treated. For the cream, it is generally applied directly to the affected area once or twice a day. The shampoo is used by massaging into wet hair and leaving it for several minutes before rinsing, typically twice a week. Oral tablets are usually prescribed at a dose of 200 mg once daily, though higher doses may be necessary for severe systemic infections.

Mechanism of Action

Ketoconazole, the active component of Nizoral, operates by inhibiting the synthesis of ergosterol, an essential component of the fungal cell membrane. By impairing ergosterol production, Nizoral increases cell membrane permeability and ultimately leads to cell death, thereby reducing fungal infection.

Pharmacokinetic Properties

Nizoral tablets are absorbed inconsistently in the gastrointestinal tract, and bioavailability may be affected by gastric pH. The oral absorption of ketoconazole is increased in acidic environments. Topical formulations are minimally absorbed into the systemic circulation, focusing their action on the external site of application. The drug is metabolized primarily in the liver and excreted in bile and urine.

Potential Drug Interactions

Ketoconazole can interact with a range of medications, potentially altering drug efficacy or increasing adverse effects. It is known to inhibit cytochrome P450 enzymes, especially CYP3A4, which may increase the serum concentrations of certain drugs like statins, benzodiazepines, and anticoagulants. Interaction with antacids or medications that alter stomach pH may reduce ketoconazole absorption.

Side Effects Overview

Common side effects associated with Nizoral include gastrointestinal disturbances such as nausea and vomiting, especially with oral tablets. Cutaneous and topical applications may cause local irritation or itching. Less commonly, serious liver function impairment has been reported with systemic use, necessitating regular monitoring of liver enzymes during extended treatment courses.

Use in Specific Populations

Nizoral should be used with caution in specific populations. In patients with liver disease, alternative treatments should be considered due to the risk of hepatotoxicity. Pregnant or breastfeeding women should use the drug under healthcare supervision, as ketoconazole may affect fetal development or be excreted in breast milk.

Storage and Handling Recommendations

Nizoral should be stored at room temperature, away from direct sunlight and moisture. The shampoo formulation should be shaken well before use. Tablets must be kept in their original packaging to protect from moisture. Topical formulations should not be frozen and must be kept tightly closed when not in use to ensure efficacy and prevent contamination.

Contraindications and Precautions

Nizoral is contraindicated in individuals with a known hypersensitivity to ketoconazole or any other component of the formulation. Use is not recommended in patients with active liver disease. Precautions must be taken when prescribing to individuals on other medications due to the numerous potential drug-drug interactions.

Clinical Monitoring Requirements

For patients on prolonged oral Nizoral therapy, periodic liver function tests are recommended due to the risk of hepatotoxicity. Monitoring of therapeutic response is necessary to evaluate treatment efficacy and adjust dosages accordingly. Observation for adverse reactions should be continuous, especially in pediatric and geriatric populations.