Aminoglycosides and renal magnesium homeostasis in humans.
BACKGROUND
The use of aminoglycosides has been linked with hypomagnesaemia in scattered reports. The objective of the study was to measure prospectively the effect of treatment with the aminoglycoside amikacin on renal magnesium homeostasis.


METHODS
Twenty-four cystic fibrosis patients (aged 9-19 years) admitted because of exacerbation of pulmonary symptoms caused by Pseudomonas aeruginosa were treated with the aminoglycoside amikacin and the cephalosporin ceftazidime for 14 days. Renal values and plasma and urinary electrolytes were measured before and at the end of the systemic anti-pseudomonal therapy.


RESULTS
In the patients with cystic fibrosis, treatment with amikacin and ceftazidime did not modify plasma creatinine or urea and plasma or urinary sodium, potassium and calcium. Treatment with amikacin and ceftazidime significantly decreased both plasma total magnesium (from 0.77 (0. 74-0.81) to 0.73 (0.71-75) mmol/l; median and interquartile range) and ionized magnesium (from 0.53 (0.50-0.55) to 0.50 (0.47-0.52) mmol/l) concentration and increased fractional urinary magnesium excretion (from 0.0568 (0.0494-0.0716) to 0.0721 (0.0630-0.111)) and total urinary magnesium excretion (from 30.7 (26.5-38.0) to 38.5 (31. 5-49.0) micromol/l glomerular filtration rate).


CONCLUSIONS
The present study demonstrates that systemic therapy with amikacin plus ceftazidime causes mild hypomagnesaemia secondary to renal magnesium wasting even in the absence of a significant rise in circulating creatinine and urea.
von Vigier
R O
RO
Department of Pediatrics, University of Bern, Switzerland.
Truttmann
A C
AC
Zindler-Schmocker
K
K
Bettinelli
A
A
Aebischer
C C
CC
Wermuth
B
B
Bianchetti
M G
MG
D000293:Adolescent; D000583:Amikacin / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002442:Ceftazidime / Q000627:therapeutic use; D002511:Cephalosporins / Q000627:therapeutic use; D002648:Child; D003550:Cystic Fibrosis / Q000150:complications / Q000378:metabolism*; D004359:Drug Therapy, Combination / Q000627:therapeutic use*; D004573:Electrolytes / Q000097:blood / Q000652:urine; D005260:Female; D006706:Homeostasis; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D008171:Lung Diseases / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology; D008274:Magnesium / Q000378:metabolism*; D008297:Male; D011552:Pseudomonas Infections / Q000150:complications / Q000188:drug therapy*; D011550:Pseudomonas aeruginosa
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D004573:Electrolytes; D000583:Amikacin; D002442:Ceftazidime; D008274:Magnesium