Drugs online research references
Biochem Pharmacol. 1989 Mar 15;38(6):907-14.
Histamine H2-receptor mediated stimulation of gastric acid secretion by mercaptomethylimidazole.
Bhattacharjee M, Bose AK, Banerjee RK.
Department of Physiology, Indian Institute of Chemical Biology, Calcutta.
Intraperitoneal administration of mercaptomethylimidazole (methimazole), a potent antithyroid drug belonging to the thionamide group, caused a significant increase in gastric secretion both in control and pylorus-ligated mice. The drug also induced significant stimulation of gastric acid and pepsinogen secretion in both the animal systems studied. The dose-response curve indicated a nearly 10-fold increase in acid output by injection of 0.55 mg mercaptomethylimidazole per 25 g body weight. The duration profile of the drug response at the dose mentioned showed acid secretion almost at a linear rate up to 2.5 hr, after which the response decreased to some extent. Of the other antithyroid drugs of the same family, only thiourea activated acid secretion but the response was much smaller than mercaptomethylimidazole. Histamine, one of the physiological secretagogues of gastric acid secretion, was found to be less active than mercaptomethylimidazole. Mercaptomethylimidazole-induced stimulation of acid secretion could be effectively blocked by prior administration of cimetidine and completely by omeprazole and not by atropine. Verapamil and nifedipine had also some inhibitory effect. These observations indicate that mercaptomethylimidazole stimulates HCl secretion through the involvement of H2-receptor and through the functioning of the H+-K+-ATPase of the parietal cells. The bulk movement of water during increased HCl secretion was partially sensitive to cimetidine and omeprazole and was also associated with an increased secretion of Na+ and K+ in the gastric juice. This indicates that mercaptomethylimidazole also induced water transport through a separate mechanism.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2522782&dopt=Abstract
note: kwd match prilosec online literature
J Pharm Sci. 1998 Dec;87(12):1502-7.
Human cytochromes P450 mediating phenacetin O-deethylation in vitro: validation of the high affinity component as an index of CYP1A2 activity.
Venkatakrishnan K, von Moltke LL, Greenblatt DJ.
Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
Phenacetin O-deethylation, widely used as an index reaction for cytochrome P450 1A2 (CYP1A2) activity, displays biphasic kinetics in human liver microsomes. CYP1A2 has been identified as contributing to the high affinity component, but is not verified as the sole contributor to the high affinity phase. In addition, the human CYP isoforms accounting for the low affinity phase have not been identified. We have used heterologously expressed human CYP isoforms to identify, kinetically characterize, and predict the relative contribution of the major human liver CYP isoforms mediating phenacetin O-deethylation. CYP1A2 (Km 31 microM) is the only high affinity phenacetin O-deethylase in human liver microsomes, while CYPs 2A6 (Km 4098 microM), 2C9 (Km 566 microM), 2C19 (Km 656 microM), 2D6 (Km 1021 microM), and 2E1 (Km 1257 microM) all contribute to the low affinity phase of the reaction. Considering the relative abundance of the various CYPs in human liver, CYP1A2 accounts for 86% of net reaction velocity at a substrate concentration of 100 microM, while CYP2C9 becomes the primary phenacetin O-deethylase at substrate concentrations of 865 microM and higher and accounts for 31% of the net Vmax of the reaction. Predictions from kinetic studies on heterologously expressed CYPs are consistent with chemical inhibition studies on human liver microsomes with sulfaphenazole and alpha-naphthoflavone that suggest a greater role for CYP2C9, and a smaller role for CYP1A2, at higher substrate concentrations. Thus CYP1A2 is the only high affinity human liver phenacetin O-deethylase, thereby validating the use of the high affinity component as an index of CYP1A2 activity in human liver microsomes.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10189256&dopt=Abstract
note: kwd match prilosec online literature
Scand J Gastroenterol. 1996 Jan;31(1):1-9.
Cost effectiveness of medical versus surgical treatment in patients with severe or refractory gastroesophageal reflux disease in the Netherlands.
Van Den Boom G, Go PM, Hameeteman W, Dallemagne B, Ament AJ.
Dept. of Health Economics, University of Limburg, Maastricht, Netherlands.
BACKGROUND: For a significant number of patients with severe or refractory gastroesophageal reflux disease, maintenance treatment with omeprazole and reflux surgery (Nissen fundoplication) are alternative treatment options. In this study maintenance treatment with omeprazole is compared with open and laparoscopic Nissen fundoplication from a health-economic perspective. METHODS: Meta-analysis of published articles to assess effectiveness and simple decision-analytic techniques to combine costs and effects are used. Findings and assumptions are submitted to sensitivity analysis. RESULTS: It is estimated that it costs approximately 1880 Dutch guilders to initially heal a patient with severe or refractory esophagitis with 40 mg omeprazole daily. When medical maintenance therapy was compared with surgery, it appeared that medical maintenance therapy with omeprazole (20-40 mg daily) for a prolonged period of time (more than 4 years) is less cost effective than a Nissen procedure. It is estimated that a laparoscopic Nissen will shift this so-called break-even point towards 1.4 years, mainly due to a shorter hospital stay. CONCLUSIONS: Although caution is required in drawing conclusions, it appears that replacing treatment with (laparoscopic) Nissen fundoplications in these patients might lead to substantial savings.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8927933&dopt=Abstract
note: kwd match prilosec online literature
Herbs and Pharmaceuticals Online ||
Hair Million herbal formula for hair loss and hair growth ||
Antibiotics and prescription medications online literature ||