PHARMACOKINETICS AND PHARMACODYNAMICS OF FAMOTIDINE IN PATIENTS WITH REFLUX ESOPHAGITIS

The pharmacokinetics, pharmacodynamic effect and clinical efficacy of famotidine were studied in 10 patients with reflux oesophagitis Grades I and II. For the pharmacokinetic studies the patients received 20 mg famotidine i. v. The half-life of famotidine was 3.8 h, the total pla sma clearance was 297 ml.min-1, and a steady state volume of distribut ion of 1.2 l.kg-1 was found. For pharmacodynamic assessment, intraoeso phageal pH-metry was performed without and after acute treatment with famotidine 20 mg i. v. and following 3 weeks of oral famotidine 80 mg b.d. The resultant percentage total acid exposure time (pH < 4 within 24 h) were 23.9 %,19.0 % and 19.2 % (median), respectively (NS). At th e end of 6 weeks of oral therapy, symptomatic and endoscopic improveme nt had occurred in 9 and 5 patients, respectively. Our study shows tha t the pharmacokinetics of famotidine in patients with reflux oesophagi tis is comparable to that in healthy volunteers and peptic ulcer patie nts. The clinical response to the treatment appeared comparable to tha t found after other H-2-receptor antagonists.