amphotericin b: clinical use

Prescribing considerations

• Specify the complete product and formulation at prescribing, dispensing and administration; liposomal amphotericin B and Fungizone are not interchangeable.
• Use where anaphylaxis, severe infusion reactions, electrolyte disturbance and renal toxicity can be managed.
• Review concurrent nephrotoxic medicines and treatments that lower potassium.
• Consider the sucrose content of the selected liposomal product in people with diabetes.
• Use strict aseptic preparation because selected products contain no antimicrobial preservative.

Contraindications and cautions

• Hypersensitivity to amphotericin B or a formulation excipient, subject to the SmPC exception where infection is life-threatening and treatable only with that product.
• A previous severe allergic or anaphylactic reaction to liposomal amphotericin B precludes further infusion of that product.

Monitoring

• Assess renal function and potassium before treatment and monitor during therapy.
• Monitor magnesium, other relevant electrolytes, liver function and haematological indices.
• Observe during every infusion for allergic, haemodynamic and respiratory reactions.
• Monitor pulmonary function when treatment is temporally associated with leukocyte transfusion.

Clinical pharmacology

Amphotericin B is a polyene that binds fungal membrane sterols and disrupts membrane permeability. Its effect may be fungistatic or fungicidal depending on exposure and organism susceptibility. Liposomal encapsulation produces pharmacokinetics distinct from conventional sodium-deoxycholate amphotericin and reduces distal renal tubular exposure.

Formulation and product differences

• Fungizone is a conventional sodium-deoxycholate formulation; Amphotericin B Tillomed liposomal encloses the active substance within phospholipid liposomes.
• The formulations have different pharmacokinetic, toxicity and administration characteristics and must not be substituted directly.
• The liposomal formulation is less nephrotoxic than conventional amphotericin B, but important renal and electrolyte adverse effects still occur.
• Both selected products require water-based reconstitution followed by compatible glucose/dextrose diluent; saline can cause incompatibility or precipitation.
• The selected liposomal product contains sucrose, whereas Fungizone uses sodium deoxycholate and phosphate-buffer excipients.

Dispersion for infusion

Route: Intravenous

Strengths: 50 mg