RT Journal A1 Sacks SL, Smith JL, Pollard RB, et al T1 TOxicity of vidarabine JF JAMA JO JAMA YR 1979 FD January 5 VO 241 IS 1 SP 28 OP 29 DO 10.1001/jama.1979.03290270020010 UL http://dx.doi.org/10.1001/jama.1979.03290270020010 AB To the Editor.—  Previously we described two patients who were treated with vidarabine (adenine arabinoside) for chronic hepatitis B infection (239:1648, 1978). Since this report we have treated 13 other patients with similar regimens. A summary of side effects related to this drug in all 15 patients follows. Twelve of these 15 patients were receiving human leukocyte interferon concomitantly.All 15 patients have experienced gastrointestinal symptoms (one or more of the following: anorexia, weight loss, vomiting, loose stools, and constipation). Eleven of the 15 described their symptoms as mild. Four of 15 suffered more severe discomfort, and one required cessation of therapy because of uncontrolled vomiting. With the exception of weight loss, which occasionally took weeks to reverse, gastrointestinal symptoms were quickly relieved in all patients by stopping the drug therapy.Seven of 15 patients experienced weakness or fatigue. All were receiving human leukocyte interferon, a drug also commonly associated