DOES ONCE-DAILY DOSING OF AMINOGLYCOSIDES AFFECT NEUROMUSCULAR FUNCTION

Objective: Aminoglycosides have been reported to produce a curare-like neuromuscular blockade in animals at serum concentrations higher than those obtained with traditional dosing (1-2 mg/kg every 8 h) in human s. Aminoglycoside-induced neuromuscular blockade is rarely, if ever, s een in humans with traditional dosing. The recent adoption of once-dai ly dosing of aminoglycosides has raised concerns about increased poten tial for this adverse effect because higher serum concentrations are p roduced. The objective of this study was to determine if once-daily do sing of aminoglycosides inhibits respiratory muscle function. Method: Nine mechanically ventilated ICU patients on once-daily dosing of gent amicin 6 mg/kg/day were assessed for respiratory muscle strength by me asuring maximum inspiratory pressure (MIP). MIP is a measurement of th e maximal negative pressure generated by repeated inhalations against an occluded airway over 20 s. This was measured within I hour before ( MIPpre) and within I hour after each aminoglycoside dose (MIPpost). Re sults: Mean values for MIPpre and MIPpost were -26.7 cm H2O and -26.5 cm H2O, respectively. The mean difference between MIPpre and MIPpost w as -0.2 cm H2O, which was not statistically significant (P>0.05). Conc lusion: The effect of gentamicin (6 mg/kg/day) on respiratory muscle f unction was not statistically, nor clinically significant, and weaning from mechanical ventilation does not seem to be inhibited by once-dai ly dosing of aminoglycosides as detectable by measurement of MIP.