Enhancement of Tetracycline Blood Levels

FOUR different tetracycline preparations — namely, tetracycline phosphate complex,1 2 3 4 5 6 7 tetracycline base with sodium hexametaphosphate,2 , 4 , 5 , 7 8 9 tetracycline hydrochloride with citric acid4 , 5 , 9 and tetracycline hydrochloride with glucosamine hydrochloride10 , 11 — have been made available during the past few months. Each of these preparations has been reported as providing higher blood levels when compared with similar doses of tetracycline hydrochloride, and some of them have been reported as yielding higher levels than others.The difficulties in evaluating most of the published reports have been pointed out elsewhere.12 , 13 In particular, many of the comparisons have been made with capsules, some of which contained calcium compounds, and . . .