Comparison between the effects of neostigmine and ranitidine on interdigestive gastroduodenal motility of patients with gastroparesis.
The antroduodenal motor effects of ranitidine, and H2-receptor antagonist with cholinergic activity, and neostigmine, a cholinomimetic drug, were compared in 16 patients with idiopathic gastroparesis characterized by dysmotility-like dyspepsia, delayed gastric emptying at scintigraphy and absence of gastroduodenal phase 3 of the migrating motor complex during a manometric recording of at least 300 min. After overnight fasting in 8 of these patients, neostigmine was administered intravenously at a dose of 0.5 mg, and in the remaining 8 patients ranitidine was given intravenously at a dose of 100 mg. Ranitidine induced a gastroduodenal phase 3 activity in a significantly (p < 0.02) higher percentage of patients (87.5%) in comparison with neostigmine (25%). In the majority of patients, neostigmine induced only an irregular increase in gastroduodenal motor activity sometimes characterized by propagated and nonpropagated clustered contractions. This property of ranitidine of inducing a phase 3 activity in these patients cannot be ascribed to its weak cholinergic activity, as neostigmine, which has a more intense cholinergic activity than ranitidine, is unable to produce the effect demonstrated by ranitidine. Another unknown mechanism able to trigger the neurohormonal program of migrating motor complex phase 3 or to abolish inhibitory influences should be taken into account to explain this effect of ranitidine.
Bortolotti
M
M
First Medical Clinic, University of Bologna, Italy.
Cucchiara
S
S
Sarti
P
P
Brunelli
F
F
Mazza
M
M
Bagnato
F
F
Barbara
L
L
D000328:Adult; D005260:Female; D005769:Gastrointestinal Motility / Q000187:drug effects*; D018589:Gastroparesis / Q000188:drug therapy* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D009388:Neostigmine / Q000627:therapeutic use*; D011899:Ranitidine / Q000627:therapeutic use*
D009388:Neostigmine; D011899:Ranitidine