Mycostatin (Nystatin)

Mycostatin is a polyene antifungal used to manage fungal infections of the oral cavity and gastrointestinal tract.

• Oral candidiasis (thrush): reduces fungal load and resolves symptoms such as white plaques and discomfort.
• Gastrointestinal candidiasis: eradicates Candida overgrowth in the digestive system, relieving abdominal pain and diarrhea.
• Prophylaxis in patients on broad‑spectrum antibiotics: helps prevent secondary Candida infection by maintaining fungal balance.

• Nystatin binds selectively to ergosterol, a key sterol component of fungal cell membranes. This binding creates pores that increase membrane permeability, leading to leakage of intracellular contents and ultimately fungal cell death. Because human cell membranes contain cholesterol rather than ergosterol, Nystatin exhibits selective toxicity toward fungal organisms.

Nystatin is generally well tolerated, but adverse reactions can occur.

Common Side Effects

• Nausea: mild to moderate upset stomach.
• Vomiting: occasional episodes after ingestion.
• Diarrhea: loose stools during treatment.
• Abdominal cramps: discomfort in the lower abdomen.
• Altered taste: temporary metallic or bitter sensation.
• Mild skin rash: localized erythema at the mouth.

Serious or Rare Side Effects

• Anaphylaxis: severe allergic reaction with difficulty breathing.
• Stevens‑Johnson syndrome: rare severe skin eruption.
• Hepatic dysfunction: signs of liver injury such as jaundice.
• Severe gastrointestinal upset: persistent vomiting or bloody stools.
• Nephrotoxicity: rare kidney impairment when used with other nephrotoxic agents.
• Hematologic abnormalities: uncommon drops in white blood cell counts.

Before prescribing Mycostatin, consider the following safety measures.

• Assess renal function: adjust use in patients with severe renal impairment.
• Monitor for hypersensitivity: discontinue if signs of allergic reaction appear.
• Use cautiously in premature infants: limited safety data are available.
• Avoid in patients with known hypersensitivity to polyene antifungals.
• Review concomitant antibiotic therapy: broad‑spectrum antibiotics may alter efficacy.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Nystatin may interact with other medicines; awareness of the interaction level is important.

Major Interactions (Avoid)

• Concurrent systemic amphotericin B: increased risk of nephrotoxicity.
• High‑dose oral corticosteroids: may diminish antifungal effectiveness.

Moderate Interactions (Monitor Closely)

• Broad‑spectrum antibiotics: may disrupt gut flora and affect Candida colonisation.
• Antacids containing aluminum or magnesium: could affect dissolution of oral suspension.
• Oral probiotics: may compete with Nystatin activity, requiring monitoring of therapeutic response.