Home Drug Guide Ketoconazole

Drug Guide

Generic Name

Ketoconazole

Brand Names Nizoral, Nizoral Anti-dandruff, Extina, Xolegel, Ketozole

Classification

Therapeutic: Antifungal

Pharmacological: Imidazole antifungal

FDA Approved Indications

  • Fungal infections of the skin and nails
  • Seborrheic dermatitis (dandruff)
  • Candidiasis, systemic (limited use due to toxicity)

Mechanism of Action

Ketoconazole inhibits fungal cytochrome P450 enzymes, impairing ergosterol synthesis which compromises fungal cell membrane integrity.

Dosage and Administration

Adult: Typically, 2% topical cream or shampoo applied as directed; oral formulations vary, but systemic use is limited due to toxicity.

Pediatric: Dosing varies by condition and age; consult specific guidelines.

Geriatric: Adjust doses if necessary; monitor for hepatic function.

Renal Impairment: No specific dose adjustment for topical use; systemic use requires caution.

Hepatic Impairment: Use with caution; systemic administration contraindicated in severe hepatic impairment.

Pharmacokinetics

Absorption: Poorly absorbed from topical preparations; systemic absorption can occur with oral and topical formulations depending on site and integrity of the skin.

Distribution: Extensively distributed in tissues, especially skin and nails.

Metabolism: Hepatic via CYP3A4 enzyme.

Excretion: Feces and urine in small amounts.

Half Life: 2 hours (topical), 20-36 hours (systemic)

Contraindications

  • Hypersensitivity to ketoconazole or azole antifungals.

Precautions

  • Hepatic impairment, use with caution.
  • Potential for drug interactions via CYP3A4.
  • Pregnancy category C; use only if clearly needed.

Adverse Reactions - Common

  • Skin irritation, itching, or redness (Common)

Adverse Reactions - Serious

  • Hepatotoxicity (elevated liver enzymes, hepatitis, liver failure) (Rare)
  • Drug interactions leading to QT prolongation and arrhythmias (Rare)

Drug-Drug Interactions

  • CYP3A4 inhibitors and inducers (e.g., rifampin, ketoconazole, clarithromycin)
  • QT prolonging agents (e.g., certain antiarrhythmics)

Drug-Food Interactions

  • Avoid concomitant use with substances affecting hepatic metabolism.

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor hepatic function and for signs of hepatic toxicity; assess for skin reactions during topical therapy.

Diagnoses:

  • Risk for hepatotoxicity
  • Impaired skin integrity

Implementation: Administer topicals as prescribed; educate regarding proper application.

Evaluation: Monitor liver enzymes; assess for resolution or improvement of fungal infection.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Report signs of liver problems (e.g., jaundice, dark urine).
  • Use topical formulations as directed; avoid contact with eyes.
  • Be aware of potential drug interactions.

Special Considerations

Black Box Warnings:

  • Hepatotoxicity, including rare cases of liver failure.

Genetic Factors: N/A

Lab Test Interference: None significant.

Overdose Management

Signs/Symptoms: Gastrointestinal distress, dizziness, potential hepatotoxicity.

Treatment: Supportive care, monitor liver function, and symptomatic treatment.

Storage and Handling

Storage: Store at room temperature, away from moisture and light.

Stability: Stable for 2-3 years when stored properly.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.