Tetracyclines and Renal Failure

Twenty-five per cent of patients presenting with acute deterioration of renal function had been prescribed tetracycline in the previous two weeks. These patients required dialysis when their serum creatinine level was lower than that of the group of patients who had not taken tetracycline. Acidosis was more profound in these patients, and the serum phosphate level was higher. The prognosis in this group was excellent, with the serum creatinine and blood urea levels returning to their previous values. Dialysis was required to correct the “uraemia” and to remove tetracycline. The conventional tetracyclines should not be used in patients with impaired renal function, but a new tetracycline (doxycycline) that is excreted by the intestinal tract does not accumulate to toxic levels and may be used safely.