EFFECT OF DIETARY CHLORIDE CONTENT ON THE ELIMINATION OF BROMIDE BY DOGS

The effect of dietary chloride content (0.2, 0.4 and 1.3 per cent chlo ride on a dry matter basis) on the disposition of a single oral dose o f bromide (14 mg kg(-1)) was evaluated in normal beagles. Increasing t he dietary chloride content from 0.2 to 1.3 per cent resulted in a sig nificant decrease in the mean apparent elimination half-life from 69 /- 22 days to 24 +/- 7 days. The mean area under the concentration cur ve (AUG) for dogs fed 1.3 per cent chloride was significantly smaller than the AUC for dogs fed 0.2 per cent chloride. Dietary chloride had no effect on the maximum serum concentrations (C-max) or on the time ( T-max) to reach the maximum concentrations. The steady-state serum bro mide concentrations predicted from the single dose data for daily dose s of 14 mg kg(-1) of bromide were significantly lower in dogs fed 1.3 per cent chloride (310 +/- 150 mg litre(-1)) than in dogs fed 0.2 per cent chloride (1950 +/- 1140 mg litre(-1)). The predicted mean daily d oses of bromide necessary to maintain serum levels within the therapeu tic range for dogs fed 1.3 per cent chloride (43 +/- 13 mg kg(-1)) wer e almost twice as high as the dose estimated for dogs fed 0.4 per cent chloride (22 +/- 3 mg kg(-1)) and nearly three times as high as the d ose estimated for dogs fed 0.2 per cent chloride (15 +/- 4 mg kg(-1)). These differences were statistically significant (P=0.002).