Abstract | BACKGROUND: Parenteral polymyxin use declined after the 1960s, due to safety concerns. An increase in multidrug-resistant (MDR) gram-negative infections and a shortage of new agents have prompted increased use of parenteral polymyxin. OBJECTIVE: METHODS: Paper pharmacy records were used to identify patients aged 18 years or older, presence of MDR gram-negative bacteremia or UTI, and use of parenteral polymyxin B for at least 48 hours. Electronic and paper patient records were then retrospectively reviewed. Polymyxin B susceptibility was evaluated using the Kirby-Bauer method. MDR isolates were defined as resistant to at least 3 antimicrobial classes, excluding polymyxin B. Microbiologic clearance was defined by 1 repeat urine or 2 repeat blood cultures that were sterile or growing different organisms. Secondary outcomes included hospital mortality and nephrotoxicity, defined as an increase in serum creatinine of 0.5 mg/dL or more, or a 50% reduction in creatinine clearance. RESULTS: Seventeen infections in 16 patients were treated with polymyxin B (1 pt. had 2 infections that were analyzed separately). Microbiologic clearance occurred in 14 of 16 (88%) cases of MDR gram-negative bacteremia or UTI in which repeat cultures were done. Ten of 16 patients died (all-cause mortality 63%). Five patients required hemodialysis prior to polymyxin B use. Six (55%) of the remaining 11 patients with baseline renal insufficiency developed nephrotoxicity, and none of them required hemodialysis. The mean +/- SD number of days from the initiation of therapy to the onset of nephrotoxicity was 7.5 +/- 2.3 (range 4-10) days. Three (50%) of 6 patients with nephrotoxicity died. CONCLUSIONS: Our data suggest that polymyxin B may be effective for MDR gram-negative infections in patients with limited therapeutic options, but precautions should be taken to avoid toxicity.
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Authors | Andrew A Pastewski, Patricia Caruso, Addison R Parris, Ramon Dizon, Robert Kopec, Shobha Sharma, Suri Mayer, Monica Ghitan, Edward K Chapnick |
Journal | The Annals of pharmacotherapy
(Ann Pharmacother)
Vol. 42
Issue 9
Pg. 1177-87
(Sep 2008)
ISSN: 1542-6270 [Electronic] United States |
PMID | 18664609
(Publication Type: Journal Article)
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Chemical References |
- Anti-Bacterial Agents
- Polymyxin B
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Topics |
- Adult
- Aged
- Aged, 80 and over
- Anti-Bacterial Agents
(administration & dosage, adverse effects, therapeutic use)
- Bacteremia
(drug therapy, microbiology)
- Drug Resistance, Multiple, Bacterial
- Gram-Negative Bacteria
(drug effects)
- Gram-Negative Bacterial Infections
(drug therapy)
- Humans
- Male
- Microbial Sensitivity Tests
- Middle Aged
- Polymyxin B
(administration & dosage, adverse effects, therapeutic use)
- Retrospective Studies
- Urinary Tract Infections
(drug therapy, microbiology)
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