Evaluation of a potential clinical interaction between ceftriaxone and calcium.

In April 2009, the FDA retracted a warning asserting that ceftriaxone and intravenous calcium products should not be coadministered to any patient to prevent precipitation events leading to end-organ damage. Following that announcement, we sought to evaluate if the retraction was justified. A search of the FDA Adverse Event Reporting System was conducted to identify any ceftriaxone-calcium interactions that resulted in serious adverse drug events. Ceftazidime-calcium was used as a comparator agent. One hundred four events with ceftriaxone-calcium and 99 events with ceftazidime-calcium were identified. Adverse drug events were recorded according to the listed description of drug involvement (primary or secondary suspect) and were interpreted as probable, possible, unlikely, or unrelated. For ceftriaxone-calcium-related adverse events, 7.7% and 20.2% of the events were classified as probable and possible for embolism, respectively. Ceftazidime-calcium resulted in fewer probable embolic events (4%) but more possible embolic events (30.3%). Among cases that considered ceftriaxone or ceftazidime and calcium as the primary or secondary drug, one case was classified as a probable embolic event. That patient received ceftriaxone-calcium and died, although an attribution of causality was not possible. Our analysis suggests a lack of support for the occurrence of ceftriaxone-calcium precipitation events in adults. The results of the current analysis reinforce the revised FDA recommendations suggesting that patients >28 days old may receive ceftriaxone and calcium sequentially and provide a transparent and reproducible methodology for such evaluations.

Impact of the FDA warning of potential ceftriaxone and calcium interactions on drug use policy in clinical practice.

OBJECTIVE: In September 2007, the FDA issued an alert recommending that ceftriaxone and calcium-containing solutions should not be administered to any patient within 48 h of each other. Due to the widespread use of ceftriaxone, significant concern was expressed by the greater healthcare community about the warning, which the FDA eventually retracted in April of 2009. We sought to quantify the impact of the warning on healthcare institutions. SETTING: A survey was administered to the membership of the Society of Infectious Diseases Pharmacists to quantify perceived changes in ceftriaxone use among healthcare institutions across the United States. METHOD: A survey of Infectious Diseases experts was conducted. Participants were queried for hospital policies/drug use statistics during two times: immediately after the FDA warning and approximately 13 months post warning (preceding the FDA retraction). MAIN OUTCOME MEASURE: Related changes in formulary, drug-use policy, and the number of employee hours that were devoted to addressing the FDA warning were assessed. RESULTS: Ninety-four surveys representing 94 hospital systems were included in the analysis. Approximately half (n = 49, 52%) of respondent institutions enacted at least one drug-use policy change based on the warning; one institution removed ceftriaxone from a clinical protocol. Institutions' final interpretations of the warning differed slightly from initial understanding of the warning, and there was an overall minor decrease in the perceived use of ceftriaxone. The majority of those surveyed (n = 70, 74%) estimated that their respective institutions devoted between 1 and 49 employee hours to address the warning. CONCLUSION: Hospitals with ID pharmacists had minimal changes to ceftriaxone use after the 2007 FDA warning. Specialized pharmacists may be uniquely situated to help hospitals interpret global recommendations locally.