Nilstat (Nystatin)

Nilstat (nystatin) is used to treat fungal infections of the gastrointestinal tract and related mucosal surfaces.

• Oral candidiasis (thrush): Reduces fungal load and alleviates symptoms such as white plaques and discomfort in the mouth.
• Esophageal candidiasis: Eradicates Candida species from the esophageal lining, improving swallowing and reducing pain.
• Intestinal candidiasis: Controls overgrowth of Candida in the gut, helping to resolve diarrhea and abdominal discomfort.

• Nystatin exerts its antifungal activity by binding selectively to ergosterol, a key sterol component of fungal cell membranes. This interaction creates pores that increase membrane permeability, leading to leakage of intracellular electrolytes and macromolecules, ultimately causing cell death. Because human cells contain cholesterol instead of ergosterol, nystatin’s action is largely confined to fungal organisms, especially those residing in the oral and gastrointestinal mucosa.

Nystatin may cause a range of adverse reactions, most of which are mild and limited to the gastrointestinal tract.

Common Side Effects

• Nausea: Mild stomach upset.
• Diarrhea: Loose stools, usually self‑limiting.
• Abdominal pain or cramps: Discomfort in the stomach area.
• Oral irritation: Burning or soreness in the mouth.

Serious or Rare Side Effects

• Severe allergic reaction (including anaphylaxis): Hives, swelling, or breathing difficulty.
• Hepatotoxicity: Uncommon liver enzyme elevation.
• Persistent vomiting leading to dehydration.

Before prescribing Nilstat, clinicians should consider several precautionary measures to ensure safe and effective use.

• Confirm diagnosis: Verify Candida infection through clinical assessment or laboratory testing.
• Assess hypersensitivity: Avoid use in patients with known allergy to nystatin or other polyene antifungals.
• Monitor renal function: Adjust therapy in severe renal impairment as systemic absorption may increase.
• Avoid concomitant oral antifungals without guidance: Potential for reduced efficacy or increased toxicity.
• Educate patient on proper administration: Instruct to retain the suspension in the mouth for several minutes before swallowing when treating oral thrush.
• Store at below 25°C: Keep in the original container, protect from moisture and direct sunlight.

Nystatin has a limited systemic profile, but certain drug combinations may require attention.

Major Interactions (Avoid)

• Concurrent systemic azole antifungals: May increase risk of hepatotoxicity due to overlapping metabolism.
• Cholestyramine or other bile‑acid sequestrants: Can bind nystatin and reduce its local activity.

Moderate Interactions (Monitor Closely)

• Antacids containing aluminum or magnesium: May alter gastric pH and affect drug dissolution.
• Broad‑spectrum antibiotics: Can disrupt normal flora, potentially increasing Candida overgrowth after treatment.
• Proton pump inhibitors: May change gastric acidity, influencing nystatin’s efficacy in the esophagus.
• Oral corticosteroids: May predispose to recurrent candidiasis, requiring closer monitoring.