Pharmacokinetic evaluation of liposomal amphotericin B (L-AMB) in patients with invasive fungal infection: Population approach in Japanese pediatrics.

The pharmacokinetic characteristics of liposomal amphotericin B (L-AMB; AmBisome(®)) in patients with invasive fungal infection were investigated. A population pharmacokinetic (PK) model in Japanese pediatric patients was developed based on 159 serum amphotericin B (AMPH-B) concentrations obtained in a post-marketing clinical study. The subjects were 39 patients with a mean age of 8.4 years (SD 4.5) and mean body weight of 27.1 kg (SD 14.1). A two-compartment PK model with zero-order input and first-order elimination was fitted to serum AMPH-B concentrations for L-AMB doses of 1.0, 2.5, and 5.0 mg/kg/day. Body weight showed significant correlations with PK parameters, such as clearance (CL) and distribution volume of the central compartment (Vc). The predicted Cmax/dose and AUC0-24/dose in Japanese pediatric patients were similar to those in non-Japanese pediatric patients and Japanese adult patients. Extremely large increases in Ctrough compared with predicted values were observed in some Japanese pediatric patients, but no relationships with demographic characteristics, clinical laboratory test values, or representative adverse drug reaction (decreased potassium) were found. The population PK parameters in this study are useful for simulating PK profiles of L-AMB and will be helpful for PK exposure comparisons among different populations and in investigations of pharmacokinetic-pharmacodynamic characteristics in patients. CHEMICAL COMPOUNDS: Amphotericin B Deoxycholate (PubChem CID:23668620); amphotericin B (PubChem CID:5280965); 3-nitrophenol (PubChem CID:11137); methanol (PubChem CID:887).

Evaluation of the safety and efficacy of liposomal amphotericin B (L-AMB) in children.

A multicenter, uncontrolled clinical study has been conducted to evaluate the safety, efficacy, and pharmacokinetics of liposomal amphotericin B (L-AMB) in children. In this article, the safety and efficacy of L-AMB are discussed. Subjects were diagnosed with invasive fungal infection (definitely diagnosed cases), possible fungal infection (clinically diagnosed cases), and febrile neutropenia with suspected fungal infection (febrile neutropenia cases). Of the 39 subjects treated with L-AMB, 18 received a definite (11) or clinical (7) diagnosis of invasive fungal infection. In these subjects, excluding one unevaluable subject, L-AMB was effective in nine out of 17 subjects(52.9%). Of 12 febrile neutropenia cases, improvement in clinical symptoms, etc., was observed for six but these were excluded from the efficacy analysis because they concomitantly used medications that may have affected efficacy. The causative fungus was identified in four out of 39 subjects and confirmed to be eliminated by treatment with L-AMB in one subject. Adverse events possibly related to L-AMB (adverse drug reactions) were reported in 36 out of 39 subjects (92.3%). The most commonad verse drug reaction was decreased potassium in 20 out of 39 subjects (51.3%), but all these subjects recovered with appropriate treatment, for example potassium supplementation.In a Japanese Phase II clinical study of adult patients, the incidence of adverse drug reactions was 95.3%(82/86 subjects) and the efficacy was 63.6% (42/66). Taken together, these data indicate that the safety and efficacy of L-AMB are almost the same in pediatric and adult patients.