Moronal (Nystatin)

Nystatin acts against Candida species in the oral and gastrointestinal tracts, providing antifungal therapy for mucosal infections.

• Oral candidiasis (thrush): reduces fungal load and resolves oral lesions and discomfort.
• Esophageal candidiasis: treats infection, alleviates pain and dysphagia, and promotes mucosal healing.
• Prophylaxis of Candida infections: prevents colonisation and infection in immunocompromised or high‑risk patients.

• Nystatin binds selectively to ergosterol, a key sterol in fungal cell membranes. This binding creates pores that increase membrane permeability, leading to leakage of essential intracellular ions and molecules, disruption of cellular homeostasis, and ultimately fungal cell death. Its activity is confined to the gastrointestinal lumen because it is poorly absorbed systemically.

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

Common Side Effects

• Nausea: mild to moderate stomach upset after oral administration.
• Vomiting: occasional expulsion of the dose.
• Abdominal discomfort: cramping or pain in the stomach area.
• Diarrhoea: loose stools during treatment.
• Altered taste: temporary metallic or bitter sensation.
• Mild skin rash: localized erythema at the site of contact.

Serious or Rare Side Effects

• Severe allergic reaction (anaphylaxis): difficulty breathing, swelling, or hives.
• Hepatic dysfunction: abnormal liver enzymes or jaundice.
• Stevens‑Johnson syndrome: severe skin blistering and mucosal involvement.
• Persistent severe diarrhoea: may indicate secondary infection.
• Significant electrolyte imbalance: due to extensive GI loss.
• Rare systemic toxicity: in patients with compromised gut integrity.

When prescribing or dispensing Nystatin, consider the following safety measures.

• Assess renal function: adjust use in patients with severe renal impairment.
• Monitor for allergic reactions: discontinue if signs of hypersensitivity appear.
• Avoid in known hypersensitivity to polyene antifungals: contraindicated for affected individuals.
• Use only as directed: ensure patients follow the prescribed regimen.
• Store at room temperature: keep in the original packaging, protect from moisture and direct sunlight.

Nystatin has limited systemic absorption, but certain co‑administered agents may affect its efficacy or safety.

Major Interactions (Avoid)

• Concomitant use with systemic azole antifungals: may increase risk of additive toxicity.
• Co‑administration with cholestyramine or other bile‑acid sequestrants: can reduce Nystatin’s local activity.

Moderate Interactions (Monitor Closely)

• Use with broad‑spectrum oral antibiotics: may predispose to overgrowth of resistant organisms.
• Concurrent probiotic therapy: could alter gut flora and affect therapeutic outcomes.
• Interaction with antacids containing aluminum or magnesium: may affect drug dissolution and local concentration.