Letters Section Editor: Robert M. Golub, MD, Senior Editor.
In Reply: Drs Abumrad and Barbul note that prestudy and 6-month plasma arginine levels were similar in the placebo and active therapy groups. Although poor adherence is one possible explanation, pill counts at 1 month, 3 months, and 6 months indicate otherwise. We suggested that in this cohort with normal baseline arginine levels, up-regulation of enzymes responsible for arginine catabolism, as described by Morris1 and Castillo et al,2 is a more likely mechanism. The product we used was L-arginine hydrochloride, produced with a good manufacturing practice label.
Schulman SP, Gerstenblith G. Arginine Therapy for Acute Myocardial Infarction—Reply. JAMA. 2006;295(18):2138-2140. doi:10.1001/jama.295.18.2139