Drug shortages and implications for pediatric patients.

Drug shortages in the United States continue to be a significant problem that negatively impacts pediatric patients of all ages. These shortages have been associated with a higher rate of relapse among children with cancer, substitution of less effective agents, and greater risk for short- and long-term toxicity. Effective prevention and management of any drug shortage must include considerations for issues specific to pediatric patients; hence, the Pediatric Pharmacy Advocacy Group (PPAG) strongly supports the effective management of shortages by institutions caring for pediatric patients. Recommendations published by groups such as the American Society of Health-System Pharmacists and the American Society for Parenteral and Enteral Nutrition should be incorporated into drug shortage management policies. PPAG also supports the efforts of the Food and Drug Administration (FDA) to not only address but prevent drug shortages caused by manufacturing and quality problems, delays in production, and discontinuations. Prevention, mitigation, and effective management of drug shortages pose significant challenges that require effective communication; hence, PPAG encourages enhanced and early dialogue between the FDA, pharmaceutical manufacturers, professional organizations, and health care institutions.

Practice-based validation of calcium and phosphorus solubility limits for pediatric parenteral nutrition solutions.

In an effort to maximize the precipitation-free delivery of calcium and phosphorus to neonates, Fitzgerald and MacKay published in 1986 the results of empirical determination of calcium-phosphate saturation curves for a number of parenteral nutrition (PN) solutions. The saturation curves generated from these investigations have been used to formulate thousands of PN solutions. The curves were developed testing only calcium and phosphate without other components added to PN solutions. The authors reviewed 38,019 PN orders from 2007-2010 and plotted the calcium and phosphate concentrations for each solution in relation to the published curves to assess the practical validity of the curves. The solutions reviewed were compounded using standard weight ranges for electrolytes, trace minerals, and vitamins. The solutions were evaluated for precipitation using standards for visual compatibility against a black and white background. There were no visual precipitates found in the 38,019 PN solutions. All calcium and phosphorus concentrations plotted below the precipitation limits predicted by the published curves despite a large range of concentrations of electrolytes and minerals. There has always been concern about extrapolating data from solubility curves that were developed empirically from a limited number of test solutions based on the few variables of calcium, phosphorus, amino acid concentration, and presence of cysteine HCl and/or fat emulsion. This experience validates the calcium and phosphorus solubility limits represented by published curves. Moreover, the findings support the concept that principal variables governing calcium and phosphorus precipitation in PN solutions are calcium, phosphorus, amino acid concentrations, temperature, and pH.

Population pharmacokinetic and pharmacodynamic modeling of high-dose intermittent ticarcillin-clavulanate administration in pediatric cystic fibrosis patients.

BACKGROUND: The Intermountain Cystic Fibrosis Pediatric Center utilizes ticarcillin-clavulanate 400 mg/kg/d divided every 6 hours, (maximum 24 g/d). This dosing strategy is higher than the Food and Drug Administration (FDA)-approved package labeling. We evaluated the microbiologic efficacy of this dosing regimen. OBJECTIVES: The primary study objective was to predict the pharmacokinetic (PK) and pharmacodynamic (PD) MIC breakpoints (the highest MIC with a probability of target attainment [PTA] of at least 90%) for the bacteriostatic and bactericidal targets of ticarcillin activity against Pseudomonas aeruginosa using the study dosing regimen. A secondary objective was to evaluate the tolerability profile of the higher ticarcillin-clavulanate dosing regimen in children with cystic fibrosis (CF). METHODS: This was a population-based PK-PD modeling study of pediatric CF patients admitted from January 1, 2005 to December 31, 2009 who received the dosing regimen for at least 7 days. Population PK and PD models were used to estimate PK and PD parameters for 127 clinically evaluable patients. A 10,000-patient Monte Carlo simulation was performed to estimate the target time in which free drug concentrations exceeded the MIC of the infecting organism. The 2 PK-PD targets of microbiologic efficacy included ≥30% for bacteriostasis and ≥50% for bactericidal effects of ticarcillin-clavulanate at higher than FDA-approved doses. RESULTS: A total of 127 patients (age, 0-19 years) met inclusion criteria. Serum concentration levels were modeled in this patient population using published PK parameters with intermittent ticarcillin peak concentrations reaching 288 (93.4) mg/L. The model predicted the PTA of the MICs for P. aeruginosa with a near-maximal bactericidal PK-PD MIC breakpoint of 16 µg/mL and a bacteriostasis PK-PD MIC breakpoint of 32 µg/mL. CONCLUSIONS: The results of our simulation suggest that in this select pediatric population, higher than FDA-approved doses of ticarcillin-clavulanate were effective in achieving bactericidal effects among pseudomonal isolates with MICs <16 µg/mL. Bacteriostatic and bactericidal effects were not frequently achieved among P. aeruginosa isolates with MICs >32 µg/mL. Additional studies are warranted to determine the clinical effectiveness of this dosing regimen.

A survey of the utilization of anti-pseudomonal beta-lactam therapy in cystic fibrosis patients.

The purpose of this study was to characterize the utilization of anti-pseudomonal beta-lactam antibiotics in the treatment of acute pulmonary exacerbations (APE) among Cystic Fibrosis Foundation (CFF)-accredited care centers. An anonymous national cross-sectional survey of CFF-accredited care centers was performed using an electronic survey tool (SurveyMonkey.com®). One hundred and twenty-one of 261 centers completed the survey (46%) representing 56% (14,856/26,740) of patients in the CFF Patient Registry. One hundred and nineteen of 121 (98%) respondents reported using beta-lactams for the treatment of APE. Intermittent dosing regimens constituted 155/167 (93%) reported regimens, while extended infusions were 12/167 (7%). Ceftazidime was the most commonly utilized beta-lactam comprising 74/167 (44%) of all infusions (intermittent and extended) of which 70/74 (95%) were intermittent infusions. The majority of intermittent ceftazidime regimens (56/70; 80%) were at doses lower than CFF and European guidelines recommended doses. In conclusion, a great majority of respondents use intermittent anti-pseudomonal beta-lactam antibiotics, with over half of respondents utilizing lower than guidelines recommended doses. While this is of concern, it is not known if optimization of dosing strategies according to guidelines recommendations will result in clinical benefit.

High dose intermittent ticarcillin-clavulanate administration in pediatric cystic fibrosis patients.

BACKGROUND: The Intermountain Cystic Fibrosis Pediatric Center utilizes ticarcillin-clavulanate 400mg/kg/day divided every 6h, (maximum 24 g/day). This dosing strategy is higher than the Cystic Fibrosis Foundation (CFF) recommendations and the Food and Drug Administration (FDA) approved package labeling. The purpose is to determine the safety of this dosing regimen. METHODS: A retrospective study of pediatric cystic fibrosis (CF) patients admitted from January 1, 2005 to December 31, 2009 who received the dosing regimen for at least 7 days. Baseline and follow-up laboratory parameters were recorded. Statistical analysis was performed. RESULTS: 127 patients met inclusion criteria. The mean (+ or - SD) ticarcillin dose was 3.5 g (+ or - 2.16) every 6 h; while the mean (+ or - SD) total ticarcillin dose was 13.5 g (+ or - 6.5) per day. No significant differences occurred in liver function tests, white blood count, and platelet count from baseline. Serum creatinine showed a statistically significant decrease from baseline. CONCLUSIONS: Higher than FDA approved doses of ticarcillin-clavulanate may be safely used in the treatment of exacerbations in pediatric cystic fibrosis patients.