Comparison of the efficacy and safety of amikacin once or twice-a-day in the treatment of severe gram-negative infections in the elderly.

The aim of this study was to compare the efficacy and safety of amikacin given either as single injection or as two injections within 12-h interval in the treatment of severe gram-negative infections in elderly patients. Thirty-nine non-selected consecutive patients of a general internal medicine facility were randomized to receive the same total daily dose of amikacin either as a single dose (19 patients) or divided into two doses injected at 12-h interval (20 patients). Amikacin was used alone or in combination with metronidazole, clindamycin, fosfomycin or a beta-lactam. Clinical and bacteriological responses were satisfactory and comparable in the two groups. There was no difference between the once/day and the twice-a-day groups with respect to drug dosage, duration of therapy and concomitant treatment. Only one patient (BID group) showed a rise of serum creatinine during the observation period. Amikacin alone or in combination can be regarded as an efficacious and safe antibiotic in the treatment of severe gram-negative infections in elderly patients, whether the daily dose is administered in a single infusion or in a BID interval.

Pharmacokinetic study of cefuroxime in the elderly.

1 The pharmacokinetics of cefuroxime have been investigated in 18 patients at least 70 years old. The drug was given either by continuous infusion (7 cases) or by multiple injections (11 cases) for 3 to 11 days (mean duration: 7 days). 2 The unchanged drug was assayed in blood plasma and in the urine by high performance liquid chromatography (h.p.l.c). 3 Cefuroxime was cleared, unchanged, almost exclusively by the kidneys, even when kidney function was impaired. Creatinine clearance ranged from 1.02 to 4.08 1/h (17 to 68 ml/min) in this group of patients and plasma clearance of cefuroxime varied from 1.02 to 8.16 1/h (17 to 136 ml/min) (r = 0.7 P less than 0.001 for linear correlation), but the apparent rate constant for nonrenal elimination remained quite small (average: 0.04 h-1) and independent of creatinine clearance (r = 0.06, n = 17). 4 Since creatinine clearance decreases sharply with age, it might be suggested that cefuroxime dosage be related to creatinine clearance in the elderly, even when no renal impairment is suspected.