Long-acting echinocandin Pregnancy: US labelling §8.1: there are no data on the use of rezafungin during pregnancy to evaluate for a drug-associated risk of major birth defects, miscarriage or other adverse maternal or fetal outcomes. No adverse embryofetal outcomes were observed in pregnant rats or rabbits at approximately 5 or 3 times the clinical exposure based on AUC, and a pre- and post-natal study in rats showed no adverse effects on offspring growth, maturation or neurobehavioural/reproductive measures at up to about 5 times the recommended human dose. Verify against the UK SPC.

Rezafungin

Brand names: Rezzayo

Rezafungin is a long-acting echinocandin antifungal used for the treatment of invasive candidiasis.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 400 mg loading dose, then 200 mg once weekly thereafter

Route: Intravenous infusion over approximately one hour (about 250 mL/h) - reconstitute each 200 mg vial with 9.5 mL sterile Water for Injection to 20 mg/mL, then dilute to a total infusion volume of 250 mL in 0.9% sodium chloride, 0.45% sodium chloride or 5% dextrose; intravenous infusion only

Frequency: Once weekly

Max: The safety of rezafungin has not been established beyond 4 weekly doses; after the 400 mg loading dose, weekly doses higher than 200 mg are not approved

US FDA prescribing information (REZZAYO, Melinta Therapeutics) §2.1-2.4 - NO UK SPC (eMC) posology was present in this bundle, so this is US labelling and must be verified against the UK SPC. Infusion concentrations: 1.6 mg/mL for the 400 mg dose and 0.8 mg/mL for the 200 mg dose, each in a total volume of 250 mL. If infusion-related reactions occur, the infusion may be slowed, or paused and restarted at a lower rate. MISSED DOSES (§2.2): give a missed dose as soon as possible; if given within 3 days of the assigned day, the next weekly dose may be given on schedule; if given more than 3 days after the assigned day, revise the schedule to leave at least 4 days before the next dose; if restarting after at least 2 weeks of missed dosing, start again at the 400 mg loading dose. PAEDIATRIC: safety and effectiveness have not been established in paediatric patients. ELDERLY: clinical studies did not include sufficient numbers of older adults to determine whether patients 65 years and older respond differently.

Dose auto-extracted from US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Known hypersensitivity to rezafungin or to other echinocandins (US labelling §4)

Side effects

Hypokalaemia, hypomagnesaemia and hypophosphataemia - among the most common adverse reactions (incidence 5% or more) (US labelling §6)
Pyrexia and anaemia (US labelling §6)
Diarrhoea, vomiting, nausea, abdominal pain and constipation (US labelling §6)
Infusion-related reactions including flushing, sensation of warmth, urticaria, nausea and chest tightness; serious hypersensitivity reactions including anaphylaxis have been reported (US labelling §5.1, §5.2)
Photosensitivity - advise protection from sun exposure and other sources of UV radiation; abnormalities in liver tests have been seen in clinical trial patients (US labelling §5.3, §5.4)

Clinical monograph

How it works

It inhibits the enzyme 1,3-beta-D-glucan synthase, disrupting fungal cell wall synthesis and leading to fungal cell death.

Prescribing in practice

Hypersensitivity and infusion-related reactions can occur; administer by intravenous infusion at a controlled rate with appropriate monitoring.
Its prolonged half-life allows once-weekly dosing, which differs from other echinocandins.
Echinocandins have limited activity against some non-Candida moulds, so confirm the pathogen and susceptibility where possible.

Monitoring

Monitor liver function and clinical and microbiological response to therapy.

Counselling the patient

This antifungal is given as a drip, usually once weekly.
Report any rash, flushing or breathlessness during the infusion.
Complete the full course as advised to clear the infection.

Evidence & guidelines

Rezafungin is an MHRA-authorised echinocandin for invasive candidiasis in adults.

Reference: NICE TA957; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways