Anidulafungin

Anidulafungin is an intravenous echinocandin for candidaemia, invasive candidiasis and oesophageal candidiasis. It is eliminated by slow chemical degradation rather than by the liver or kidney, so it needs no dose adjustment for organ impairment. It has few interactions.

Class. Echinocandin antifungal.

Mechanism. Inhibits 1,3-beta-D-glucan synthase, blocking cell wall synthesis.

Pharmacokinetics. Intravenous only, highly protein bound, half life 24 to 26 hours, degraded non-enzymatically in plasma, excreted as degradation products in faeces. Poor cerebrospinal fluid and urine penetration.

Candidaemia and invasive candidiasis (adults). - Loading: 200 mg intravenously on day 1. - Maintenance: 100 mg once daily. - Duration: 14 days after the first negative blood culture and resolution of symptoms.

Oesophageal candidiasis. Load 100 mg, then 50 mg once daily for 14 days and 7 days after resolution.

Children (1 month to 17 years). Load 3 mg/kg (maximum 200 mg), then 1.5 mg/kg daily (maximum 100 mg).

Maximum: 200 mg on day 1; 100 mg daily thereafter. Titration: none.

Contraindications. Hypersensitivity to echinocandins.

Serious adverse effects. Hepatotoxicity, anaphylaxis, severe skin reactions.

Common adverse effects. Diarrhoea, hypokalaemia, raised liver enzymes, nausea and infusion-related flushing.

Interactions. Minimal; no CYP interactions.

Common prescribing errors. Infusing too fast, using it for cryptococcal infection and omitting the loading dose.

Special groups. - Pregnancy: avoid unless essential. - Breastfeeding: limited data. - Children: weight-based. - Older adults: no adjustment. - Kidney impairment: no adjustment; not removed by dialysis. - Liver impairment: no adjustment.

Formulations. Powder for infusion 100 mg vial.

Administration. Reconstitute with sterile water and dilute in 0.9% sodium chloride or 5% glucose; infuse at no more than 1.1 mg a minute (about 3 hours for 200 mg and 90 minutes for 100 mg).

Baseline. Liver tests, potassium.

Monitoring. Liver tests weekly; blood cultures until clear.

Stopping thresholds. Stop for anaphylaxis, severe skin reaction or marked hepatotoxicity.

Referral and escalation. Specialist review for candidaemia and ophthalmology review.