Colistin Risky but Essential for Some Critically Ill Kids

BY DIANA MAHONEY
Elsevier Global Medical News

BOSTON – Despite limited data on the safety and efficacy of colistin in children, the polymyxin antimicrobial has been used increasingly in high-risk pediatric patients as salvage therapy for serious infections caused by multidrug-resistant gram-negative bacteria, according to Dr. Pia S. Pannaraj.

“The escalating impact of antimicrobial selective pressure in high-risk pediatric populations has limited the therapeutic options available for the treatment of multidrug-resistant [MDR] gram-negative bacilli, which in turn has led to renewed interest in colistin, despite the known nephrotoxic and neurotoxic risks,” she reported at the annual meeting of the Infectious Diseases Society of America.

In a study designed to review risk factors for acquiring multidrug-resistant gram-negative bacteria requiring colistin treatment and the adverse effects of such treatment in pediatric patients, Dr. Pannaraj of Childrens Hospital Los Angeles and colleagues reviewed their experience with colistin in pediatric patients admitted to their hospital between Jan. 1, 2005, and Oct. 31, 2010. Based on pharmacy records for that period, 53 children were treated with intravenous or nebulized colistin for treatment or suppressive therapy of an infection caused by MDR bacteria. Of the 53 children, 14 received 18 courses of the drug and were included in the analysis, she said. Control patients with matching underlying conditions were chosen from the medical records database.

MDR was defined as resistance to at least three classes of antibiotics, Dr. Pannaraj said. The underlying conditions reported in the 14 study patients included cystic fibrosis in 8, non–cystic fibrosis chronic lung disease in 3, and malignancy in 1, she said, noting that “2 of the patients were previously healthy.”

Analysis showed that the children with an MDR isolate requiring colistin had more hospital days during the previous calendar year, compared with their matched controls, at 101.0 days vs. 27.2 days, respectively, Dr. Pannaraj reported. Those with MDR isolates also received more types of antibiotic than did the matched controls (6.6 vs. 4.2) for longer durations (191.0 vs. 53.8 antibiotic days).

Four gram-negative bacteria were isolated, including 16 Pseudomonas aeruginosa, 6 Acinetobacter baumannii, 3 Klebsiella pneumoniae, and 1 Alcaligenes species, with more than one pathogen isolated in seven children, she said. The indications for treatment with colistin included pulmonary exacerbation, wound infection, and bacteremia/sepsis.

Creatinine levels doubled in two children, Dr. Pannaraj reported. Two of the children developed neurologic symptoms, including perioral tingling in one and headache in another; symptoms resolved after the drug course was completed.

“We need more studies on the dosing and safety of colistin to optimize it for the treatment of high-risk children,” Dr. Pannaraj said.

VITALS
Major Finding: Of 14 high-risk pediatric patients, 4 experienced nephrotoxic and neurotoxic side effects from treatment with the polymyxin antimicrobial colistin, including doubled creatinine levels in 2 patients, perioral tingling in 1, and headache in 1.
Data Source: Retrospective analysis of single-institution experience with intravenous or nebulized colistin for salvage therapy of serious infections caused by multidrug-resistant gram-negative bacteria.
Disclosures: Dr. Pannaraj had no financial conflicts of interest to disclose.