Parenteral control of gastric acid hypersecretion in patients with
Zollinger-Ellison syndrome is increasingly required; however, existing methods of determining the required dose are cumbersome and not applicable in all centers. A previous study suggested that the required parenteral dose of
histamine H2-receptor antagonists correlated with the previous oral dose. In the present study, in 31 patients with
Zollinger-Ellison syndrome we evaluated the hypothesis that an effective parenteral
histamine H2-receptor antagonist dose could be predicted from the previous oral dose. Twenty-three patients were taking oral
ranitidine (mean 1.3 g/day), six patients
famotidine (152 mg/day), and two patients
cimetidine (1.8 g/day). Each patient was treated with a continuous
intravenous infusion of the equivalent dose of
ranitidine (mean dose 1 mg/kg/hr with 35% requiring 0.5 mg/kg/hr, 49% 1 mg/kg/hr, 3% 1.5 mg/kg/hr, 10% 2 mg/kg/hr, and 3% 2.5 mg/kg/hr. This dose of
ranitidine acutely controlled
acid secretion (< 10 meq/hr) in all patients. To evaluate long-term efficacy and safety, 20 patients were maintained on this dose through the peri- and postoperative periods. Mean duration was 7.1 days with 25% treated 3-5 days, 40% 6-8 days, 30% 8-10 days, and 5% > 10 days. The predicted dose continued to control
acid secretion in 95% of patients with one patient requiring one dose adjustment. No biochemical, clinical, or hematological toxicity was seen, although
ranitidine was stopped in one patient because of
skin rash. These results demonstrate that the parenteral dose of
ranitidine required to control
acid secretion in patients with
Zollinger-Ellison syndrome can be predicted from the oral dose.(ABSTRACT TRUNCATED AT 250 WORDS)