Letters Section Editor: Stephen J. Lurie,
MD, PhD, Senior Editor.
In Reply: Drs Carbonin and Zuccalà note
that the Digitalis Investigation Group (DIG) trial1 only
evaluated patients in sinus rhythm. As such, the relevance of our analysis
to patients with atrial fibrillation is not known. We support their call for
additional research in this area.
Mr de Denus and Dr Spinler suggest that observed differences in glomerular
filtration rates are insufficient to explain differences in SDCs between patients
with a SDC between 0.5 and 0.8 ng/mL and patients with a SDC of 1.2 ng/mL
and higher.3 As we noted, recommended digoxin
doses were not only based on renal function but also included patients' age,
sex, weight, and other medications.
Rathore SS, Curtis JP, Wang Y, Bristow MR, Krumholz HM. Optimal Digoxin Concentrations for Patients With Heart Failure. JAMA. 2003;289(20):2643. doi:10.1001/jama.289.20.2643-a