EFFECTS OF INTRAVENOUS CLARITHROMYCIN ON BILE DYNAMICS AND DUODENOGASTRIC REFLUX IN PATIENTS WITH HYPOKINETIC GALLBLADDER

We studied the effects of clarithromycin, a new macrolide compound whi ch is a structural analogue of erythromycin, on gallbladder filling an d emptying and on duodenogastric reflux. Gallbladder dynamics and duod enogastric reflux were studied by means of sequential cholescintigraph y in which the trimethyl-Br-IDA radionuclide excreted in bile was meas ured externally by a gamma-camera interfaced to a computer for 60 min in the fasting state and for 60 min after a standard cholecystokinetic meal. Seven subjects with documented gallbladder hypokinesia and with out biliary obstruction or hepatic disease were studied. Each patient was studied twice: first during a constant intravenous infusion of cla rithromycin for a period of 20 min at an infusion rate of 1.5 mg/kg an d second during an intravenous infusion of placebo. The isotope appear ance time in the duodenum decreased after clarithromycin from 38.0 +/- 7.8 min to 17.8 +/- 2.8 min (p = 0.03) and gallbladder filling time f rom 40.5 +/- 5.5 min to 26.3 +/- 4.0 min (p = 0.003). The percentage o f residual activity in the gallbladder after 90 min and 120 min was le ss after drug than after placebo (68 +/- 6.1% and 49 +/- 8% vs 87.4 +/ - 3.3% and 77.7 +/- 3.8% respectively; p = 0.007 and p = 0.005). The g allbladder emptying rate was significantly greater after drug (6.2 +/- 1.2 min-1 vs 2.6 +/- 0.3 min-1; p = 0.003). Thus, clarithromycin indu ced activation of biliary washout and more rapid gallbladder filling i n the fasting state and earlier gallbladder emptying and accelerated e jection speed after a meal.