BACKGROUND/AIMS: We performed a randomized, double-blind, phase III, multicenter trial to assess the comparative efficacy and safety of revaprazan, which is a novel acid pump antagonist in comparison with ranitidine for treating patients suffering with acute gastritis and acute aggravation of chronic gastritis. METHODS: Five hundred and twelve subjects were randomized to 2 weeks of treatment with either revaprazan 200 mg q.d. or ranitidine 150 mg b.i.d. The primary efficacy parameter was the estimated improvement rate according to endoscopy, and the secondary efficacy parameter was the improvement rate for the subjects' symptoms. RESULTS: The estimated improvement rates at 2 weeks (intention-to-treat analysis) were 79.9% with revaprazan and 60.5% with ranitidine; a significant difference was found between the two groups (p<0.0001). On the per-protocol analysis, the estimated improvement rates for revaprazan and ranitidine were 79.4% and 60.2%, respectively. There was a significant difference in the estimated improvement rates between the two groups (p<0.0001). On both analyses, there were no significant differences between the two groups for the improvement rates of the subjects' symptoms. Both drugs were well tolerated. CONCLUSIONS: The efficacy of revaprazan was higher than that of ranitidine for the estimated improvement rate according to endoscopy and also for the symptomatological improvement rate, and revaprazan was well tolerated by the subjects suffering with gastritis.
Endoscopy ; Gastritis* ; Humans ; Ranitidine

No abstract available.
Cimetidine* ; Liver* ; Ranitidine*

Bioequivalents of two preparations composing of Ranitidine. A randomised crossover controlled single dose study was performed on 18 healthy volumteers (9 males and 5 females) aged from 22 to 40 years old. For each subject of each preparation 1 tablet composing of 150mg of ranitidine was administered orally. Plasma levels of ranitidine were evaluated by HPLC. The dissolution rate of different preparations showed that their properties were similar. Bioequivalent was evalnated statistacally (by diverse methods as ANOVA, confidence interval, West lke and Schurimann). No significant difference in plasma level of these 2 preparations was reforted. No side effect was noted
Ranitidine ; Therapeutic Equivalency ; Pharmaceutical Preparations

No abstract available.
Hypersensitivity, Delayed* ; Ranitidine* ; T-Lymphocytes*

The effects of histamine type 2(H2) receptor antagonists, cimetidine and ranitidine, on the induction of contact hypersensitivity and UVB induced suppression of contact hypersensitivity were studied. Our experiment showed that treatment with cimetidine or ranitidine slightly enhanced contact hypersensitivity to DNCB, but the suppression of contact hypersensitivity elicited by UVB were moderatly reversed by ranitidine. These facts suggest that H2-receptor antagonist may be responsible for th blocking histamine induced suppressor factor by acting upon UV-induced suppressor T cell.
Cimetidine ; Dermatitis, Contact* ; Dinitrochlorobenzene ; Histamine ; Ranitidine

No abstract available.
Humans ; Ranitidine* ; T-Lymphocyte Subsets* ; T-Lymphocytes*

This study was undertaken to observe the effects of centrally administred antihistamines on the blood pressure. Diphenhydramine(DPH), a H1-receptor antagonist, and ranitidine(RAN), a H2-receptor antagonist were administered intracerebroventricularly(icv) on urethane-anesthetized rabbits. 1) Both DPH and RAN administered intraccebroventricularly increased blood pressure, however the intravenous(iv) adminstration of them did not affect blood pressure. The pressor response to icv DPH was dose-dependent, but that to icv RAN was not. 2) The pressor response to icv DPH(1mg) was either markedly attenuated or reversed to depressor response by the pretreatment with icv phentolamine(250,500ug), and iv chlorisondamine(0.1, 1mg/Kg) and iv phenoxybenzamine(1mg/Kg). In cord-sectioned rabbtis, icv RAN) 1mg) did not produce pressor response. 3) The pressor responsr to icv RAN(1mg) was not affected by the pretreatment with icv phentolamine(500ug), iv chlorisondamin(1mg/Kg) and iv phenoxybenzamine(1mg/Kg), and iv phenoxybenzamine(1mg/Kg). RAN also producted pressor response in cordsectioned rabbits. These results suggest that the pressor response to icv DPH is elecited by increasing peripheral sympathetic tone via the stimulation of central alpha-adrenoreceptors and the pressor response to icv RAN is produced by releasing some humoral facotr which can increase blood pressure.
Blood Pressure ; Diphenhydramine* ; Histamine Antagonists ; Rabbits* ; Ranitidine*

The main purpose of this study was to develop a novel, in situ gel system for sustained delivery of ranitidine hydrochloride. Ranitidine in situ gels at 0.2%, 0.5%, and 1.0% gellan gum concentration (w/v) were prepared, respectively, and characterized in terms of preparation, viscosity and in vitro release. The viscosity of the gellan gum formulations in solution increased with increasing concentrations of gellan gum. In vitro study showed that the release of ranitidine from these gels was characterized by an initial phase of high release (burst effect) and translated to the second phase of moderate release. Single photon emission computing tomography technique was used to evaluate the stomach residence time of gel containing 99mTc tracer. The animal experiment suggested in situ gel had feasibility of forming gels in stomach and sustained the ranitidine release from the gels over the period of at least 8 h. In conclusion, the in situ gel system is a promising approach for the oral delivery of ranitidine for the therapeutic effects improvement.
Animal Experimentation ; Gels ; Gingiva ; Ranitidine* ; Stomach ; Viscosity

Histamine type 2 (H2) receptor antagonists are widely used for stress ulcer prophylaxis in critical and postoperative care. Though ranitidine is one of the most commonly used H2 receptor antagonists, with a low incidence of adverse reactions, a few anaphylactic reactions associated with ranitidine have been reported. This report describes 2 additional cases of anaphylaxis induced by ranitidine used for stress ulcer prophylaxis.
Anaphylaxis ; Histamine ; Incidence ; Postoperative Care ; Ranitidine ; Ulcer

BACKGROUND: Aspiration pneumonia remains a serious result associated with general anesthesia. Therefore, we studied the effectiveness of preanesthetic ranitidine in increasing gastric pH to prevent aspiration pneumonia. METHODS: Eighty patients scheduled for elective surgery were randomly divided into four groups with twenty patients in each group. Patients in control group were not given preanesthetic ranitidine; patients in group I received 300 mg of ranitidine orally at night before surgery, patients in group II received 150 mg of ranitidine orally both the night before surgery and one hour before surgery respecvtively and patients in group III recieved 150mg of ranitidine orally one hour before surgery. RESULTS: Compared with control group, the mean gastric pH of preanesthesia and 1 hour after anesthetic induction increased significantly in the group I, II, III (P<0.0001). There was significant increased gastric pH in the group II compared with group I and III. CONCLUSIONS: These results demonstrate that ranitidine markedly increase the gastric pH. So, we recommend that patients receiving general anesthesia would be taken Hz-antagonist such as ranitidine preoperatively.
Anesthesia, General ; Humans ; Hydrogen-Ion Concentration* ; Pneumonia, Aspiration ; Premedication ; Ranitidine*