NALIDIXIC ACID (NegGram) is an antibacterial agent used in the treatment of urinary-tract infections. Nalidixic acid (1-ethyl-7-methyl-1,8-naphthyridin-4-one-3-carboxylic acid) is not related to sulfonamides, antibiotics, or nitrofurans. It may be an effective agent against some of the intractable gram-negative bacteria, includingProteus, Escherichia coli, Aerobacter, andKlebsiella. The average daily dose of nalidixic acid for a child of 6 to 14 years of age is 1 to 2 gm, and that for an adult, 2 to 4 gm. Reports of toxicity have been few, and the side effects of this drug have been considered minimal. The commoner toxic symptoms encountered with its use are nausea, vomiting, and drowsiness or weakness. Of 120 patients treated with this drug, Ward-Mcquaid et al1found only one with a skin rash, while another with duodenal ulcer had nausea. Barlow2in 1963 reported a maculopapular rash on the trunk and lower limbs of two