Letters Section Editor: Stephen J. Lurie,
MD, PhD, Senior Editor.
In Reply: In response to Dr Shen, patients
with contrast-induced nephropathy typically experience an acute increase in
serum creatinine level after the contrast exposure, and this generally returns
to baseline by 7 to 10 days.1 It is possible
that volume expansion due to intravenous saline might explain the nonsignificant
change in the mean serum creatinine level in the control group. Although we
did not measure renal function beyond 7 days, the short half-life of acetylcysteine
and its short period of administration are not consistent with the delayed
development of nephropathy. Studies on the prophylactic use of acetylcysteine
have yielded conflicting results.2,3 This
is probably because the incidence of contrast-induced nephropathy is difficult
to estimate and is highly dependent on the definition of acute renal failure,
as well as on the patient population studied.
Kay J. Outcomes of Medical vs Invasive Therapy for Elderly Patients With Angina. JAMA. 2003;289(21):2794-2796. doi:10.1001/jama.289.21.2794-a