Nystatin

Brand Names: Mycostatin

Drug Class: Polyene antifungal

Overview

Nystatin is a polyene antifungal medication used primarily to treat oral candidiasis (thrush). It works by binding to ergosterol in fungal cell membranes, creating pores that lead to cell death. It has minimal systemic absorption when administered orally, making it well-tolerated for localized infections.

Mechanism of Action

Nystatin binds to ergosterol, a sterol component of fungal cell membranes. This binding creates pores in the membrane, disrupting membrane integrity and causing leakage of intracellular components, ultimately leading to fungal cell death.

Indications

  • Treatment of oral candidiasis (thrush)

Common Doses

  • 100,000 units/mL oral suspension

Dosage

For oral candidiasis: Typically 4-6 mL (400,000-600,000 units) four times daily, swished in the mouth and swallowed. Treatment usually continues for at least 48 hours after symptoms resolve.

Contraindications

  • Hypersensitivity to nystatin or any component of the formulation

Side Effects

  • Oral irritation
  • Nausea
  • Vomiting
  • Diarrhea
  • Gastrointestinal upset
  • Rash/urticaria
  • Stevens-Johnson syndrome (very rare)
  • Tachycardia
  • Bronchospasm
  • Facial swelling
  • Myalgia

Interactions

  • No significant drug-drug interactions documented due to minimal systemic absorption

Counseling Points

  • Swish suspension in mouth for several minutes before swallowing
  • Continue treatment for full prescribed duration even if symptoms improve
  • Avoid eating or drinking for 15-30 minutes after administration
  • Shake well before use
  • Store at room temperature