Gentamicin-induced nephropathy

Serum creatinine levels during cardiac surgery: absence of effect by aminoglycosides

The literature indicates that the relative nephrotoxicities of the three drugs used in this investigation are gentamicin > tobramycin > or = netilmicin. Serum creatinine levels over time were used in an attempt to elucidate the situation. They varied widely in all three groups and in controls in theatre. No definite trend was shown. Measurements performed for the ICU period showed continued variation. Fluctuations were so great during the perioperative period that the levels were analysed in terms of 44 mumol/litre difference between admission and discharge, ignoring changes between these times. It is now clear that the operative procedure itself is associated with fluctuating serum creatinine levels. The use of these aminoglycosides does not measureably affect the situation adversely over the short period of treatment. The use of nomograms, based on creatinine levels, to set aminoglycoside doses during the perioperative period may therefore be misleading, because of the wide fluctuations shown.

Aminoglycoside nephrotoxicity in obstructive jaundice

PURPOSE

Although it is known that liver disease predisposes to aminoglycoside nephrotoxicity, specific features of such disease that may predispose to aminoglycoside-induced renal injury have not been identified. We sought to identify such features.

PATIENTS AND METHODS

We undertook a retrospective review of the charts of 42 consecutive patients with biliary obstruction and/or cholangitis who had received more than three doses of an aminoglycoside.

RESULTS

Comparison of patients in whom aminoglycoside nephrotoxicity did and did not develop revealed no differences in age, race, sex, dose, and duration of aminoglycoside therapy; mean peak and trough aminoglycoside levels; initial pre-treatment levels of serum creatinine, aspartate transaminase, alkaline phosphatase, or albumin; or prothrombin time. The initial pre-treatment serum bilirubin level was higher in the patients in whom aminoglycoside nephrotoxicity developed (12.2 +/- 8.8 mg/dl versus 3.4 +/- 3.2 mg/dl, p less than 0.01). Aminoglycoside nephrotoxicity occurred in eight patients (19 percent): in seven of 15 patients (47 percent) with an initial bilirubin value greater than 5.0 mg/dl, but in only one of 27 patients (4 percent) with an initial bilirubin value below 5.0 mg/dl (p less than 0.01). The pre-treatment bilirubin level correlated with the change in creatinine during aminoglycoside therapy (n = 42, r = 0.66, p less than 0.01).

CONCLUSION

Aminoglycosides should probably be avoided in patients with biliary obstruction and a high serum bilirubin level.

Potentiation of ototoxicity by glutathione depletion

The combination of 10 mg/kg ethacrynic acid (ETA) and 100 mg/kg kanamycin (KA) caused neither morphologic damage to the cochlea nor change in the auditory brain stem response of the chinchilla. However, after pretreatment with a single dose of buthionine sulfoximine (BSO; 800 mg/kg intraperitoneally) to reduce intracellular glutathione (gamma-glutamylcysteinylglycine; GSH) levels, the above single administration of ETA and KA resulted in complete deafness and severe morphologic damage. The kidney, which has a rapid GSH turnover and is therefore especially susceptible to GSH depletion by BSO, also demonstrated severe damage after this treatment. A similar rapid turnover of GSH and resulting limited capacity to detoxify reactive metabolites and free radicals may determine cochlear and renal vulnerability to this toxicity. These findings may explain the clinical observations of enhanced ototoxicity in patients administered amino-glycoside antibiotics concomitantly with loop diuretics.

Ticarcillin plus clavulanic acid versus moxalactam therapy of osteomyelitis, septic arthritis, and skin and soft tissue infections

A controlled, randomized study to compare the efficacy and safety of ticarcillin plus clavulanic acid with moxalactam was carried out in 25 evaluable patients with bone, joint, and skin or skin structure infections. Of the 13 patients in the ticarcillin plus clavulanic acid-treated group, nine had osteomyelitis, two had septic arthritis, one had cellulitis, and one had a wound infection. Four of the 12 moxalactam-treated patients had osteomyelitis, one had septic arthritis, and the other seven had cellulitis and/or infected ulcers. A total of 21 causative organisms were isolated in the group treated with ticarcillin plus clavulanic acid: Enterobacteriaceae (10), Pseudomonas aeruginosa (five), obligate anaerobes (three), Staphylococcus aureus (two), and Acinetobacter species (one). Cultures in the moxalactam-treated group yielded 23 pathogens: Enterobacteriaceae (seven), S. aureus (six), group B streptococci (four), P. aeruginosa (two), obligate anaerobes (two), Streptococcus pyogenes (one), and Aeromonas species (one). A cure or satisfactory response was achieved in 12 of the 13 (92 percent) patients who received ticarcillin plus clavulanic acid and in 10 of the 12 (83 percent) patients who received moxalactam. One patient with septic arthritis who received ticarcillin plus clavulanic acid had a relapse during therapy, as did one moxalactam-treated patient with a post-surgical wound infection. The other patient in whom moxalactam treatment failed had a wound infection that became reinfected. Some abnormalities in laboratory parameters occurred in each group, but none was severe enough to warrant discontinuation of treatment.

Effect of furosemide on aminoglycoside-induced nephrotoxicity and auditory toxicity in humans

We analyzed data from three prospective, controlled, randomized, double-blind clinical trails to determine whether furosemide increases the nephrotoxicity and auditory toxicity of aminoglycosides. All patients who received at least 72 h of treatment and who had no other cause for nephrotoxicity or auditory toxicity were included in the analysis. Nephrotoxicity developed in 10 of 50 (20.0%) patients given furosemide and in 38 of 222 (17.1%) patients not given furosemide (P greater than 0.3). Auditory toxicity developed in 5 of 23 patients (21.7%) given furosemide and in 28 of 119 patients (23.5%) not given furosemide (P greater than 0.3). In each case, the groups receiving and not receiving furosemide did not differ in mean age, initial creatinine, duration of aminoglycoside therapy, mean change in auditory acuity or creatinine, mean number of days to the development of toxicity, the frequency with which gentamicin, tobramycin, amikacin, or cephalothin was administered, or the mean predose and 1-h postdose plasma aminoglycoside levels. We conclude that furosemide use should not be considered a major risk factor for the development of aminoglycoside-induced nephrotoxicity or auditory toxicity.