To the Editor.—
Janardan D. Khandekar, MD, and Harlan Edelman in their article, "Studies of Amygdalin (Laetrile) Toxicity in Rodents" (242:169, 1979), reported lethality in rats from intraperitoneal injections of 250, 500, and 750 mg/kg for five days. At the two highest doses, a large number of deaths occurred promptly after only one or two injections. The authors do not appear to have sought an explanation for the discrepancy between their results and those of at least two other laboratories.1,2 Wodinsky and Swiniarski1 gave Sprague Dawley rats 500 and 1,000 mg/kg of amygdalin on days 1, 3, and 6; the first deaths did not occur until days 9 and 10, when untreated controls also died as a result of the Walker 256 tumors they bore. In studies by my colleagues and me2 in Walker 256 tumor-bearing Wistar CFN rats, it was possible to give 1,000 mg/kg of