Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In recent years there have been some reports of tolerance occurring in man with the antisecretory effect of H2 antagonists. We, therefore, studied the effect of 300 mg and 600 mg ranitidine (CAS 66357-35-5) daily and increasing i.v. doses of pentagastrin (0.37 microgram/kg, 0.75 microgram/kg, and 1.5 micrograms/kg body weight) on gastric acid output (mmol HCl/30 min) in 9 healthy volunteers. The study design was double-blind, randomized and cross-over. Pentagastrin stimulation was performed on day 1, day 8, and day 16. Increasing i.v. doses of pentagastrin induced an almost identical enhancement of volume secretion, total acid output as well as titratable acidity on the 3 study days. A 16-days treatment period with 300 mg and 600 mg ranitidine led to 80% and 90% inhibition of pentagastrin stimulated acid output. The degree of inhibition evoked by 300 mg and 600 mg ranitidine against pentagastrin was not statistically different during the 16-days treatment period; i.e. no significant tolerance did occur within 16 days. Our data suggest that, in contrast to intragastric acidity measurements, no significant decline of inhibitory effectiveness of ranitidine against i.v. pentagastrin could be observed in healthy male volunteers.
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PMID:[Clinical studies on acid inhibition by ranitidine given simultaneously with pentagastrin]. 161 Apr 22

Acid Suppression Profile of Hydrotalcite in Man. In this randomized, double blind, placebo-controlled cross-over study, the effect of hydrotalcite (CAS 12304-65-3, Talcid), 2 tablets qid (neutralizing capacity 122 mmol) on intragastric 24-h acidity was investigated. 12 healthy male and female volunteers were administered hydrotalcite, 2 tablets qid, or placebo on 2 study days, in each case at 10, 15, 20 and 23 h. Daytime (8-22 h) and nighttime (23-7 h) intragastric H+ concentrations (mmol/l) were significantly reduced by hydrotalcite compared with placebo. The following inhibiton rates were obtained: daytime 37.4%, nighttime 31.5% (p less than 0.05). During the 2-h periods immediately after oral application of hydrotalcite or placebo inhibition rates of up to 65% were observed. These results suggest that hydrotalcite may have also antiulcer activity like other antacids which are used in the treatment of peptic ulcer disease in low daily neutralizing capacities (120-280 mmol/die).
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PMID:[Acidity profile in humans after multiple oral administration of hydrotalcite]. 177 64

A scintigraphic and pharmacokinetic study of the behaviour of (Bronchoretard forte, CAS 58-55-9) was carried out in 8 healthy male volunteers to evaluate the sensitivity of the preparation to changes in gastric pH. Volunteers were pretreated with ranitidine (CAS 66357-35-5) (150 mg b.d.) or placebo for three days prior to and on the study day to reduce gastric acidity. The effect of the pretreatment with ranitidine on gastric pH was measured on the prestudy day and the mean pH was significantly reduced compared to the placebo (ranitidine pH 2.2 +/- 2.4; placebo pH 1.6 +/- 2.0, p less than 0.01 Wilcoxon Signed Rank test). All subjects were pretreated with theophylline for 3 days (500 mg b.d.) to achieve steady-state. On the study day the volunteers swallowed two theophylline sustained release capsules radiolabelled by inclusion of indium-111 micronised Amberlite resin and the gastrointestinal transit followed continuously for 14 h using gamma scintigraphy with a further image at 24 h. Blood samples were taken from each subject throughout the study to determine the pharmacokinetic profile of theophylline when presented in the sustained release formulation. No significant differences were found in the gastrointestinal transit of the labelled microparticulates between the data obtained from the group when treated with ranitidine or placebo. Plasma theophylline concentration profiles were identical for the two treatments. These data indicate that the theophylline sustained release formulation is not sensitive to the effects of major changes in gastric H+ concentration.
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PMID:Effect of pretreatment with ranitidine on the pharmacokinetics and gastrointestinal transit of a sustained release theophylline preparation. 181 Feb 60

To compare the efficacy of ranitidine (CAS66357-35-5, Sostril) in combination with clarithromycin (CAS 81103-11-9, Cyllind) against H. pylori, a controlled randomized double-blind study was carried out. Fourty duodenal ulcer patients were treated either with ranitidine 150 mg b.i.d. and clarithromycin 500 mg q.i.d. (20 patients, group 1) or ranitidine 300 mg q.i.d. and clarithromycin 500 mg q.i.d. (20 patients, group 2) for 14 days. Both treatment groups received an additional treatment with ranitidine 300 mg daily for another 14 days. Endoscopy 6 weeks after the beginning of the trial showed complete ulcer healing in all patients. The control of H. pylori status done by CLO (Campylobacter-like organism) test and histology yielded an eradication rate of 84% (group 2) and 61% (group 1) in patients with duodenal ulcer disease treated with ranitidine and clarithromycin. Whether higher suppression of gastric acidity with a higher dose of ranitidine in combination with the antibiotic clarithromycin presents clear advantages in eradication of H. pylori should be investigated in further studies.
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PMID:[Ranitidine and clarithromycin for eradication of Helicobacter pylori in patients with duodenal ulcer]. 771 Apr 45

1,6-dihydro-2-[2-(2-methylpropoxy)anilino]-6-oxo-5-pyrimidinecarbo xylic acid, (MAR-99, CAS 98772-05-5) (10-30 mg/kg i.g.) improved the reduction of gastric blood flow rate induced by the administration of 99.5% ethanol or acidified-acetylsalicylic acid (ASA). In addition, MAR-99 (3 x 10(-6)-3 x 10(-5) mol/l) protected dose-dependently the damage of epithelial cells induced by ulcerogenic agents such as ethanol or acidified-ASA. MAR-99 (1-10 mg/kg p.o.) prevented dose-dependently the reduction of hexosamine content in glandular stomach. Furthermore, MAR-99 (10-30 mg/kg i.g.) improved the decrease in gastric potential difference induced by 99.5% ethanol and acidified-ASA. MAR-99 (10-30 mg/kg p.o.) significantly inhibited the lesion formation induced by 99.5% ethanol and such effect of this compound was not attenuated by the pretreatment with indomethacin. Furthermore MAR-99 (10 and 30 mg/kg p.o.) had no effect on the prostaglandins (PGE2 and I2) contents in the stomach of normal rats. In pylorus-ligated rats, MAR-99 (3-100 mg/kg i.d.) showed a weak or no effect on acidity and pepsin activity in gastric juice, although this compound decreased dose-dependently the volume of gastric juice. In perfused stomachs, MAR-99 (30-100 mg/kg i.d.) slightly prevented the acid secretion induced by carbachol and pentagastrin. However, MAR-99 did not affect the acid secretion stimulated by histamine. These results indicated that anti-ulcer effect of MAR-99 was mainly due to maintenance of the gastric mucosal resistance.
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PMID:Effect of 1,6-dihydro-2-[2-(2-methylpropoxy)anilino]-6-oxo-5-pyrimidinecarboxylic acid on gastric mucosal defensive factors and gastric secretion in rats. 802 35

In previous studies measuring intragastric pH in healthy volunteers it was shown that there was a faster onset of action with ranitidine (CAS 66357-35-5) 300 mg effervescent tablets (Zantac) compared to standard tablets. In a single-centre, randomised, open cross-over study the pH-values obtained over 6 h following the administration of one ranitidine 150 mg effervescent tablet were compared with those after aluminium oxide-magnesium hydroxide (algeldrate, CAS 1330-44-5, Al-Mg-hydroxide) 10 ml and placebo in healthy volunteers. 24 healthy male subjects between 19 and 32 years of age entered the study, 19 subjects were available for all three measurements. After an overnight fast, intragastric pH was monitored for 7 h using a glass electrode and a digital data recorder. The time in % during which the pH was > or = 3.5 and the area under the curve of the obtained pH-curves were compared. There was a highly statistically significant difference between ranitidine effervescent tablets versus Al-Mg-hydroxide and placebo whereas there was no such difference between Al-Mg-hydroxide and placebo. The onset of action of ranitidine effervescent tablets was almost immediate. It is concluded that there was a clear superiority of ranitidine effervescent tablets in healthy volunteers and it is suggested that pH-metry in patients with acidity-related diseases should be investigated for a better understanding of the function of effervescent tablets.
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PMID:Comparison of the effects of ranitidine effervescent tablets and magnesium hydroxide-aluminium oxide on intragastric acidity. A single-centre, randomised, open cross-over study. 876 54

This study was conducted to determine the efficacy and tolerance of ebrotidine (N-[(E)-[[2-[[[2-[(diaminomethylene)amino]-4-thiazolyl) methyl]thio]ethyl]amino]methylene]-4-bromo-benzenesulfonamide, CAS 100981-43.9, FI-3542), a new H2-receptor antagonist, on reducing gastric acidity after a single 800 mg dose, compared with cimetidine 800 mg once daily and placebo by means of a continuous intragastric pH monitoring. A total of 30 healthy volunteers were allocated to receive in a double blind, parallel design the study medication. Clinical observations, physical examinations and visual analogue scales (VAS) were performed during the study to assess the tolerability of the three treatments. Ebrotidine and cimetidine caused a greater and longer-lasting gastric acid inhibition than placebo. With ebrotidine, significantly (p < 0.05) higher median pH values (and interquartile range, IQR) were reached in the post-administration (2.61, IQR 2.02-3.93), postprandial (3.38, IQR 2.82-3.91) and nocturnal (2.83, IQR 1.69-3.77) periods than with placebo: 1.82 (IQR, 1.66-2.09), 2.81 (IQR, 2.02-3.28), and 1.89 (IQR, 1.44-2.13), respectively. Cimetidine showed significant differences compared to placebo in the post-administration (2.36, IQR 1.89-3.46) and nocturnal (2.46, IQR 1.88-4.33) periods. No statistical differences were observed between the active treatments. Ebrotidine caused a significantly higher percentage of time above pH 2.0 in the post-administration and nocturnal periods compared to placebo (p < 0.05), and above pH 3.0 in the post-administration, postprandial and nocturnal periods. No serious adverse effects, or disturbances in the VAS or in the vital signs were reported, and all medications were well tolerated. It is concluded that a single dose of ebrotidine 800 mg is as effective as cimetidine 800 mg in reducing total and nocturnal intragastric acidity. The study also confirms the excellent safety profile of the new drug.
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PMID:Continuous intragastric pH monitoring in the evaluation of ebrotidine, cimetidine and placebo on gastric acidity in healthy volunteers. 920 61

A scintigraphic and pharmacokinetic study of the behavior of Bronchoretard forte (theophylline, CAS 58-55-9) was carried out in 8 healthy male volunteers to evaluate the sensitivity of the preparation to changes in gastric pH. The volunteers were pretreated with ranitidine (CAS 66357-35-5) (150 mg b.i.d.) or placebo for three days prior to and on the study day to reduce gastric acidity. The effect of the pretreatment with ranitidine on gastric pH was measured on the day before study begin and the mean pH was significantly increased compared to the placebo (ranitidine pH 2.2 +/- 2.4; placebo pH 1.6 +/- 2.0, p < 0.01 Wilcoxon Signed Rank test). All subjects were pretreated with theophylline for 3 days (500 mg b.i.d.) to achieve steady state. On the study day, the volunteers swallowed two theophylline sustained release capsules, radiolabelled by inclusion of indium-111 micronised Amberlite resin, and the gastrointestinal transit was followed continuously for 14 h using gamma scintigraphy with a further image at 24 h. Blood samples were taken from each subject throughout the study to determine the pharmacokinetic profile of theophylline in the sustained release formulation. No significant differences were found in the gastrointestinal transit of the labelled microparticulates between the data obtained from the group treated with ranitidine and that from the placebo group. Plasma theophylline concentration profiles were identical for the two treatments. These data indicate that the theophylline sustained release formulation is not sensitive to the effects of major changes in gastric H+ concentration.
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PMID:[The effect of pretreatment with ranitidine on the pharmacokinetics and gastrointestinal transit of a sustained-release theophylline preparation]. 967 45

IY-81149 (2-[(4-methoxy-3-methyl)-2-pyridinyl]methylsulfinyl -5-(1H-pyrrol-1-yl)-1H-benzimidazole, CAS 172152-36-2) is a new proton pump inhibitor and expected to be an antiulcer drug. Its general pharmacological effects were studied in this paper. The doses given were vehicle control, 0.3, 1, 3, 100, 300 and 1000 mg/kg and were administered orally. The animals used in this study were mouse, rat, guinea pig and beagle dog. IY-81149 decreased spontaneous locomotor activity at 1000 mg/kg and showed a weak effect in motor performance at 300 and 1000 mg/kg. IY-81149 prolonged the hexobarbital-induced sleeping time dose dependently at 100, 300 and 1000 mg/kg. Oral administration of IY-81149 caused a dose-dependent hypothermic effect up to 300 mg/kg and showed analgesic effect at 1000 mg/kg. IY-81149 produced an antisecretory effect in pylorus ligated rats. The total gastric volume and acidity were significantly decreased at doses ranging from 1 to 3 mg/kg. However, IY-81149 had no effects on general behavior, did not show anticonvulsant activity, and did not affect blood pressure and heart rate, LVP (left ventricular peak systolic pressure), LVEDP (left ventricular end diastolic pressure), LVDP (left ventricular developing pressure), DP (double product), HR (heart rate), CFR (coronary flow rate), smooth muscle contraction, respiration, intestinal transport and renal function. These findings demonstrate that IY-81149 possesses weak central nervous system action and inhibitory effects on microsomal enzymes and gastric secretion after single administration. The results suggest that IY-81149 does not exert any notable pharmacological effects on the cardiovascular system, autonomic nerve system or smooth muscle function at all doses tested.
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PMID:General pharmacology of IY-81149, a new proton pump inhibitor. 1121 26

Hypertension is a common problem in elderly patients, which usually requires chronic therapy under various physiological conditions including low gastric acidity (hypo- or anacidity). This study investigated a new salt type of amlodipine (CAS 88150-42-9) on blood pressure and hypertension-related complications in stroke-prone spontaneously hypertensive rats (SHR-SP). Amlodipine orotate was prepared by reacting orotic acid and amlodipine to increase the dissolution rate at higher gastric pH conditions. Twelve-week-old SHR-SP were randomly divided into five groups to receive either amlodipine orotate or amlodipine besylate (CAS 111470-99-6) at the doses of 3 and 10 mg/kg/day orally for four weeks. The age-matched normotensive Wistar Kyoto rats (WKY) served as the normal positive control group. The systolic blood pressure was reduced in the amlodipine treated SHR-SP in a dose-dependent manner with a similar potency irrespective of the salt type. Both amlodipines also reduced the left ventricular hypertrophy at high doses and concentration-dependently inhibited the Ca2+ induced contraction with a similar potency. Furthermore, semi-quantitative analysis of a cerebral injury revealed that the two salts of amlodipine reduced the stroke-re-lated lesions to a similar degree. These results suggest that the amlodipine orotate is effective in terms of its effects on hypertension, cardiac hypertrophy and stroke-related cerebral damage in SHR-SP.
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PMID:Effects of amlodipine orotate on hypertension-related complications in spontaneously hypertensive rats. 1647


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