LAUSR

colloidal bismuth subcitrate as active ingredient), all 20% aq. and pet., resulted in only positive reactions to bismuth preparations (+++), and this already on D2 (Figure 1D); metronidazole and tetracycline remained negative (readings until D7). Five control subjects showed no reaction to Pylera 20% pet./aq., or to colloidal bismuth subcitrate 20% pet./aq. Oral challenge tests with omeprazol 80 mg, doxycycline 200 mg, and metronidazole 200 mg, performed on a different day for each drug, with the patient taking in the first hour one third of the dose, and the remaining two thirds of the does in the second hour, remained entirely negative.