β-lactam antibiotic versus combined β-lactam antibiotics and single daily dosing regimens of aminoglycosides for treating serious infections: A meta-analysis.

Abstract Background Combining aminoglycosides with β-lactam antibiotics for treating serious infections has not been associated with reduced mortality in previous meta-analyses. However, the multiple daily aminoglycoside dosing regimen principally used in most of the included studies is inconsistent with current practice. Objective To determine if a combination of an aminoglycoside administered as a single daily dose and a β-lactam antibiotic reduces all-cause mortality in patients compared with β-lactam antibiotic monotherapy. Methods A systematic review and meta-analysis of clinical studies was performed (Prospero registration number #68506). Studies were included if they compared β-lactam antibiotic monotherapy with combined β-lactam and single daily dose aminoglycoside therapy for treating serious infections. Studies investigating multiple daily dosing aminoglycoside regimens, infective endocarditis and febrile neutropaenia were excluded. Study quality was assessed using the PEDro and Newcastle-Ottawa scoring systems. The end points for outcome analyses were 30-day all-cause mortality, clinical cure and nephrotoxicity. Results Four randomised controlled trials and five retrospective cohort studies were analysed. Compared with β-lactam antibiotic monotherapy, single daily aminoglycoside dosing in combination with β-lactam antibiotics was not associated with reduced mortality compared with β-lactam antibiotic monotherapy (n = 3686, OR 0.82, 95% CI 0.63–1.08, P = 0.10, I2 42%). A subgroup analysis of cohort studies suggested reduced mortality with combination therapy (n = 3563, OR 0.79, 95% CI 0.64–0.99, P = 0.04, I2 32%). No increased risk of nephrotoxicity was identified (n = 1110, OR 1.31, 95% CI 0.83–2.09, P = 0.40, I2 0%). Conclusions The existing evidence suggests no added survival benefit from a single daily dosing regimen of an aminoglycoside when combined with β-lactam antibiotics.