JAMA. 1992 Jan 1;267(1):83-6.
Effects of ranitidine on blood alcohol levels after ethanol ingestion. Comparison with other H2-receptor antagonists.

DiPadova C, Roine R, Frezza M, Gentry RT, Baraona E, Lieber CS.

Section of Liver Diseases and Nutrition, Bronx Veterans Affairs Medical Center 10468.

OBJECTIVE--To determine whether the H2-receptor antagonist, ranitidine, which is a potent inhibitor of gastric alcohol dehydrogenase activity in vitro, increases the bioavailability of orally administered ethanol (0.3 g/kg of body weight) and to compare the resulting blood alcohol concentrations with those of two other H2-antagonists, cimetidine and famotidine, the latter of which does not inhibit gastric alcohol dehydrogenase. DESIGN--For each of the H2-receptor antagonists, a different group of subjects was used. In each group, a paired design was adopted with each subject serving as his own control. SETTING--Hospital laboratory. SUBJECTS--Normal, healthy men aged 24 to 46 years. INTERVENTION--Eight men were treated for 1 week with ranitidine (300 mg/d), six with cimetidine (1000 mg/d), and six with famotidine (40 mg/d). MEASURES--Peak blood alcohol concentrations, areas under the blood alcohol curve, first-pass metabolism, and bioavailability of orally consumed ethanol. RESULTS--Relative to baseline, ranitidine increased the mean peak concentration and the area under the curve of blood alcohol concentrations by 34% (P less than .05) and 41% (P less than .01), respectively. First-pass metabolism of ethanol was decreased from 70 +/- 10 to 31 +/- 9 mg/kg of body weight, with a corresponding increase in ethanol bioavailability of 79.6% to 92.6%. By comparison, cimetidine had even a greater effect on blood alcohol levels, while famotidine had no significant effects. CONCLUSION--Patients treated with ranitidine or cimetidine should be warned of possible functional impairments after consumption of amounts of ethanol considered safe in the absence of such therapy.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1727201&dopt=Abstract ranitidine [PubMed]




Arzneimittelforschung. 1991 Sep;41(9):954-7.
Effects of successive doses of nizatidine, cimetidine and ranitidine on serum gastrin level and gastric acid secretion.

Yamaji Y, Omata T, Abe T, Yoshida A, Ueki S, Aita H, Morita H, Chaki K, Segawa Y, Kurimoto T, et al.

Department of Pharmacology, Zeria Pharmaceutical Co., Ltd., Saitama, Japan.

Nizatidine (N-[2-[[[2-[(dimethylamino)methyl]- 4-thiazolyl]methyl]thio]ethyl]-N'-methyl-2-nitro-1,1-ethenediamine , CAS 76963-41-2) is a new histamine H2-receptor antagonist which shows suppression of gastric acid secretion and antiulcer activity. In the present experiment, the effects of single s.c. administration of nizatidine, cimetidine and ranitidine on serum gastrin levels were studied in fasted rats. Nizatidine at 100 mg/kg increased serum gastrin level 3 h after administration, which however, returned to basal level 6 h after administration. Cimetidine and ranitidine at respective doses of 250 and 100 mg/kg markedly increased serum gastrin levels 3 and 6 h after administration. In a previous study, the suppressive effect of nizatidine on basal gastric acid secretion was 82.8% at a dose of 100 mg/kg s.c. in rat pylrus-ligated model. On the basis of these findings, changes in basal gastric acid secretion and serum gastrin level after withdrawal of nizatidine, cimetidine and ranitidine administered for 14 consecutive days were studied. One day after withdrawal, nizatidine at 100 mg/kg showed a tendency to increase the basal gastric acid secretion. However, 3 and 7 days after administration, almost no changes were obtained. Cimetidine at 250 mg/kg showed a tendency to increase the basal gastric acid secretion 7 days after withdrawal of the drug. Ranitidine at 100 mg/kg induced no changes in basal gastric acid secretion after withdrawal. No obvious influences of all drugs on serum gastrin level after withdrawals were obtained. These results indicate that consecutive administration of nizatidine may cause only a transient increase of gastric acid secretion b




J Neurochem. 1992 Apr;58(4):1347-52.
Effect of histamine H2 receptor antagonists on the secretion of cerebrospinal fluid in the cat.

Naveh Y, Kitzes R, Lemberger A, Ben-David S, Feinsod M.

Department of Pediatrics, Rambam Medical Center, Haifa, Israel.

Following a recent report that epithelial cells of the choroid plexus possess histamine H2 receptors, the effect of cimetidine and ranitidine, histamine H2 receptor antagonists, on the secretion and electrolyte content of CSF was examined. Fifty cats were divided into one control (n = 6) and six experimental groups. CSF was collected by puncture of the cisterna magna following pentobarbital anesthesia, and its volume, concentrations of Na+, K+, Cl-, and pH were determined. Cimetidine or ranitidine (50, 20, or 10 mg/kg) was injected intravenously 2 h after the start of the test, and their concentrations were measured in hourly blood samples and in 30-min aliquots of CSF in the 50 mg/kg experimental groups. Whereas the secretion of CSF did not change over 6 h in the control group, it decreased significantly by 30-60 min after injection of cimetidine or ranitidine and remained low for the following 6 1/2 h in all experimental groups except the 10-mg ranitidine group. Peak cimetidine and ranitidine concentrations in CSF in the 50-mg experimental groups were noted 60 and 90 min, respectively, after intravenous injection. CSF electrolyte concentrations and pH did not change during the test in any group. We conclude that intravenous cimetidine or ranitidine can significantly reduce CSF secretion in the cat, possibly by competitive inhibition of the histamine effect on H2 receptors located on the choroid plexus epithelial cell, or by a direct effect on the capillaries of the choroid plexus.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1347778&dopt=Abstract ranitidine






Indian Pediatr. 1991 Nov;28(11):1305-8.
Stress associated gastric bleeding in newborn--role of ranitidine.

Sarna MS, Saili A, Dutta AK, Sharma D.

Neonatal Division, Kalawati Saran Children's Hospital, New Delhi.

Stress associated gastric bleeding in sick neonates is an ominous sign and frequently heralds mortality. This study was aimed at evaluating the H2 receptor antagonist drug-ranitidine in the treatment of this bleeding. Thirty eight neonates with gastric hemorrhage were included in the study. Twenty neonates were given ranitidine while 18 acted as controls. Both groups were well matched with respect to various parameters. Gastric bleeding was controlled earlier in the ranitidine group in contrast to the control group. No untoward side effects were observed with the use of ranitidine. The use of this drug in stress associated gastric bleeding in neonates is recommended.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1808052&dopt=Abstract ranitidine






Zhonghua Zheng Xing Shao Shang Wai Ke Za Zhi. 1991 Dec;7(4):248-9, 316.
[Ranitidine in the prevention of upper gastrointestinal tract hemorrhage following thermal injury]

[Article in Chinese]

Zhang MQ.

Department of Burns, Ningbo Second Hospital.

This paper reports the use of Ranitidine in preventing upper gastrointestinal tract hemorrhage following thermal injury. In 12 hours after intravenous injection of Ranitidine, gastric pH was elevated from 3.25 +/- 0.26 to 5.16 +/- 0.47 (P less than 0.01) in twenty-one burn patients, with mean TBSA 62.6% +/- 17.2% (31%-87.5%), mean third degree BSA 41.4% +/- 18.3% (0-68%). The volume of gastric secretion was decreased from 15.81 +/- 4.4 ml to 2.85 +/- 0.9 ml. The free acid of gastric secretion was decreased from 25.74 +/- 4.42 mmol/L to 5.98 +/- 3.68 mmol/L (P less than 0.01). The total titratable acidity of gastric secretion was decreased from 44.76 +/- 5.76 mmol/L to 13.85 +/- 0.02 mmol/L (P less than 0.01). Three patients had occult blood in their gastric contents on admission, and it turned negative after Ranitidine therapy. However, during 1987-1988, the incidence of upper gastrointestinal tract hemorrhage of fifty-one patients with similar TBSA and third degree BSA burned was 21.6%. Changes in gastric secretion and lowered incidence of upper gastrointestinal hemorrhage after Ranitidine therapy suggest that Ranitidine may be effective in preventing upper gastrointestinal tract hemorrhage following thermal injury.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1811837&dopt=Abstract ranitidine






J Pharm Sci. 1991 Nov;80(11):1034-6.
Pharmacokinetics of ranitidine after partial gastrectomy in dogs.

Makil O, Kaltenbach ML, Limberg J, Harrison D, Hocking MP, Derendorf H.

Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville 32610.

The effect of gastric surgery on the pharmacokinetics of ranitidine was studied in six dogs, all serving as their own controls. Prior to and after surgery, each dog received a single oral dose (5 mg/kg of body weight) of a ranitidine solution. The surgery consisted of partial gastrectomy (antrectomy) and truncal vagotomy. Ranitidine plasma and urine concentrations were measured by reversed-phase ion-pair liquid chromatography with UV detection. Pharmacokinetic parameters were estimated by noncompartmental data analysis techniques. Gastric surgery tended to slow the absorption of ranitidine as reflected by a slight increase of the time necessary to reach the peak plasma concentration. The maximum observed plasma concentration was slightly lowered. The amount of drug absorbed remained unchanged as reflected by no change in the AUCs. Other parameters such as mean residence time, elimination half-life, apparent oral clearance, and fraction excreted unchanged in the urine remained unchanged. However, due to the small number of animals and the considerable intersubject variability, none of these trends reached statistical significance.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1815053&dopt=Abstract ranitidine






Scand J Gastroenterol. 1991 Jun;26(6):620-6.
24-hour intragastric acidity and plasma gastrin during long-term treatment with omeprazole or ranitidine in patients with reflux esophagitis.

Lind T, Cederberg C, Idstrom JP, Lonroth H, Olbe L, Lundell L.

Dept. of Surgery, Sahlgren's Hospital, Gothenburg, Sweden.

The reduction in intragastric acidity and the subsequent increase in plasma gastrin were compared during long-term treatment with either omeprazole or ranitidine in 19 patients with erosive reflux esophagitis. The patients received 40 mg omeprazole in the morning or 300 mg ranitidine twice daily. After healing, half the dose was given as maintenance treatment for 1 year. Intragastric acidity and plasma gastrin were measured 24 h before entry and monthly with the high dose and after 1, 6, and 12 months with the low dose. Omeprazole reduced intragastric acidity more effectively than ranitidine (p less than 0.001). This difference in efficacy was more pronounced during the daytime. Plasma gastrin increased more after omeprazole than after ranitidine (p less than 0.01), and both drugs showed a normal postprandial response and approached fasting levels before the next dose. During long-term treatment with 20 mg omeprazole in the morning no progressive alterations were observed in 24-h intragastric acidity or plasma gastrin.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1862300&dopt=Abstract ranitidine






Acta Physiol Hung. 1992;80(1-4):303-9.
Histamine release and SOD, allopurinol and ranitidine pretreatment in haemorrhagic shock in the rat.

Zollei I, Asakawa H, Karacsonyi S.

Department of Surgery of Szent-Gyorgyi Albert Medical University, Szeged, Hungary.

Histamine release have been demonstrated in haemorrhagic shock. There are some observations that oxygen free radicals can cause histamine release. Oxygen free radicals play a role in the pathogenesis of gastric mucosal lesions. The goal of this study was to determine whether ranitidine or SOD and allopurinol pretreatment modify the histamine release during and after the haemorrhagic shock in the rat. In the anaesthetized rat 0.1 N HCl was instilled into the stomach and the rat was bled to reduce the blood pressure to 30 mmHg for 20 min. The shed blood was reinfused. Twenty min later the stomach was removed. The area of gastric mucosal lesions were measured, histological grading was made. Blood samples taken from the carotid artery were examined by radioimmunoassay (IMMUNOTECH) to determine the plasma histamine level. Plasma histamine level did not change significantly during the preparative surgery, but there was a significant increase of histamine level by the end of shock period. After the reinfusion of the blood the plasma histamine remained essentially at the same level for five min. Oxygen free radicals did not cause an important histamine release. By the end of the experiment the histamine level decreased dramatically. Ranitidine, allopurinol and SOD pretreatment provided significant protection against the gastric mucosal lesions. Allopurinol and SOD did not influence significantly the histamine level. Ranitidine caused significant histamine release immediately after the injection and every histamine value was significantly higher in this group except for the final value which was lower than the control one. The oxygen free radicals were not found as endogenous histamine releasers in this study.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1285366&dopt=Abstract ranitidine






Agents Actions. 1991 May;33(1-2):164-6.
Effect of pentacaine and ranitidine on gastric mucus changes induced by cold-restraint stress in rats.

Nosalova V, Juranek I, Babulova A.

Institute of Experimental Pharmacology, Slovak Academy of Sciences, Bratislava, Czechoslovakia.

The potential involvement of increased mucus secretion in the antiulcer activity of a cytoprotective agent, pentacaine, and of the H2-antagonist ranitidine was studied in stressed rats. Cold-restraint stress decreased the gastric mucus content and induced haemorrhagic erosions in the stomach. Pretreatment with pentacaine and ranitidine dose-dependently diminished the extent of stress-induced gastric damage. Pentacaine prevented the depletion of mucus after stress, while ranitidine failed to affect it. In non-stressed rats only pentacaine was able to enhance mucus secretion. The stimulating effect of pentacaine on gastric mucus secretion may account for some of its antiulcer properties.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1897435&dopt=Abstract ranitidine