Renoprotective role of nifedipine during gentamicin therapy: randomized controlled trial.
OBJECTIVE
To investigate the protective effect of nifedipine, a dihydropyridine calcium-channel blocker, on renal function (glomerular and tubular) in patients treated with gentamicin, an aminoglycoside antibiotic.


METHODS
Thirty-two patients with gentamicin sensitive upper urinary tract infection have been screened and randomized to two groups. The placebo group was given gentamicin and placebo, and the intervention group gentamicin and nifedipine. Gentamicin was given in slow intravenous injection every 12 hours for 10 days, and nifedipine 10 mg orally, 3 times a day.


RESULTS
Nifedipine administration during gentamicin therapy promoted primarily the glomerular filtration. In 62% of the patients treated with nifedipine creatinine clearance increased significantly by the end of the study. In the placebo group, 69% of the patients had a creatinine clearance significantly below the baseline at the end of the study. The decrease in creatinine clearance by more than 50% from the initial values was found in 2 patients (1 in each group). There was a significant increase in gammaGT/creatinine clearance ratio in both groups at the end of therapy, indicating that nifedipine did not prevent the brush-border membranous enzyme release caused by gentamicin.


CONCLUSIONS
Nifedipine has positive effects on renal hemodynamics in patients treated with gentamicin. Most likely, the mechanism of action is an increase in glomerular filtration caused by preglomerular vasodilatation.
Vlasic-Matas
J
J
Department of Internal Medicine, Split University Hospital and School of Medicine, Drage Ivanisevica 36, 21000 Split, Croatia. jadranka.vlasic-matas@st.tel.hr
Rumboldt
Z
Z
Karelovic
D
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000627:therapeutic use*; D002121:Calcium Channel Blockers / Q000008:administration & dosage*; D016009:Chi-Square Distribution; D003404:Creatinine / Q000652:urine; D005260:Female; D005839:Gentamicins / Q000009:adverse effects / Q000627:therapeutic use*; D005919:Glomerular Filtration Rate / Q000187:drug effects*; D006801:Humans; D007684:Kidney Tubules / Q000187:drug effects*; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000008:administration & dosage*; D018709:Statistics, Nonparametric; D014508:Urea / Q000652:urine; D014552:Urinary Tract Infections / Q000188:drug therapy*; D005723:gamma-Glutamyltransferase / Q000652:urine
D000900:Anti-Bacterial Agents; D002121:Calcium Channel Blockers; D005839:Gentamicins; D014508:Urea; D003404:Creatinine; D005723:gamma-Glutamyltransferase; D009543:Nifedipine