Effects of Ramosetron on Gastrointestinal Transit of Guinea Pig.
Effects of ramosetron on gastrointestinal transit of Guinea pig.
Filed under: Drug and Alcohol Rehabilitation
J Neurogastroenterol Motil. 2013 Jan; 19(1): 36-41
Park YM, Lee YJ, Lee YH, Kim TI, Park H
A selective 5-hydroxytryptamine (5-HT) type 3 receptor antagonist, ramosetron, inhibits stress-induced abnormal defecation in animals and is currently used as a therapeutic drug for irritable bowel syndrome with diarrhea. The aim of this study is to investigate the effect of ramosetron on altered gastrointestinal (GI) transit.Male guinea pigs weighing approximately 300 g were used. The effect of ramosetron was investigated on altered GI transit induced by thyrotropin-releasing hormone (TRH), 5-HT, or mustard oil (MO). GI transit was evaluated by the migration of charcoal mixture from the pylorus to the most distal point, and expressed as a percentage (%) of charcoal migration (cm) of the total length of total small intestine (cm).The average charcoal transit was 51.3 ± 20.1% in the control (vehicle) group, whereas in the ramosetron group charcoal moved 56.6 ± 21.9%, 46.9 ± 9.14% and 8.4 ± 5.6% of the total small intestine at the concentrations of 10, 30 and 100 µg/kg, respectively. GI transit after administration of TRH (100 µg/kg), 5-HT (10 mg/kg) or MO (10 mg/kg) was accelerated compared to vehicle (5-HT, 94.9 ± 9.22%; TRH, 73.4 ± 14.7%; MO, 81.0 ± 13.7%). Ramosetron inhibited GI transit altered by 5-HT, TRH or MO.Ramosetron modulated GI transit. We suggest that ramosetron may be therapeutically useful for those with accelerated upper GI transit.
HubMed – drug
Pharmacokinetics and pharmacodynamics of the proton pump inhibitors.
Filed under: Drug and Alcohol Rehabilitation
J Neurogastroenterol Motil. 2013 Jan; 19(1): 25-35
Shin JM, Kim N
Proton pump inhibitor (PPI) is a prodrug which is activated by acid. Activated PPI binds covalently to the gastric H(+), K(+)-ATPase via disulfide bond. Cys813 is the primary site responsible for the inhibition of acid pump enzyme, where PPIs bind. Omeprazole was the first PPI introduced in market, followed by pantoprazole, lansoprazole and rabeprazole. Though these PPIs share the core structures benzimidazole and pyridine, their pharmacokinetics and pharmacodynamics are a little different. Several factors must be considered in understanding the pharmacodynamics of PPIs, including: accumulation of PPI in the parietal cell, the proportion of the pump enzyme located at the canaliculus, de novo synthesis of new pump enzyme, metabolism of PPI, amounts of covalent binding of PPI in the parietal cell, and the stability of PPI binding. PPIs have about 1hour of elimination half-life. Area under the plasmic concentration curve and the intragastric pH profile are very good indicators for evaluating PPI efficacy. Though CYP2C19 and CYP3A4 polymorphism are major components of PPI metabolism, the pharmacokinetics and pharmacodynamics of racemic mixture of PPIs depend on the CYP2C19 genotype status. S-omeprazole is relatively insensitive to CYP2C19, so better control of the intragastric pH is achieved. Similarly, R-lansoprazole was developed in order to increase the drug activity. Delayed-release formulation resulted in a longer duration of effective concentration of R-lansoprazole in blood, in addition to metabolic advantage. Thus, dexlansoprazole showed best control of the intragastric pH among the present PPIs. Overall, PPIs made significant progress in the management of acid-related diseases and improved health-related quality of life.
HubMed – drug
Recent advances in the pathophysiology and treatment of gastroparesis.
Filed under: Drug and Alcohol Rehabilitation
J Neurogastroenterol Motil. 2013 Jan; 19(1): 18-24
Oh JH, Pasricha PJ
Gastroparesis is a clinical disorder characterized by upper gastrointestinal symptoms related with delayed gastric emptying of solids and liquids in the absence of mechanical obstruction. Diabetes mellitus has been the most common cause of gastroparesis and idiopathic gastroparesis also accounts for a third of all chronic cases. The most important mechanisms of gastroparesis, as understood to date, are loss of expression of neuronal nitric oxide synthase and loss of the interstitial cells of Cajal. However, the pathogenesis of gastroparesis is poorly understood. There have been several studies on specific molecules related to the pathogenesis of gastroparesis. Additionally, the Gastroparesis Clinical Research Consortium of the National Institutes of Health has achieved several promising results regarding the pathophysiology of gastroparesis. As the progress in the pathophysiology of gastroparesis has been made, a promising new drug therapy has been found. The pathophysiology and drug therapy of gastroparesis are focused in this review. Until now, the real-world medication options for treatment of gastroparesis are limited. However, it is expected to be substantially improved as the pathophysiology of gastroparesis is elucidated.
HubMed – drug
Malaria in pregnancy.
Filed under: Drug and Alcohol Rehabilitation
Mediterr J Hematol Infect Dis. 2013; 5(1): e2013010
Takem EN, D’Alessandro U
Pregnant women have a higher risk of malaria compared to non-pregnant women. This review provides an update on knowledge acquired since 2000 on P. falciparum and P.vivax infections in pregnancy. Maternal risk factors for malaria in pregnancy (MiP) include low maternal age, low parity, and low gestational age. The main effects of MIP include maternal anaemia, low birth weight (LBW), preterm delivery and increased infant and maternal mortality.P. falciparum infected erythrocytes sequester in the placenta by expressing surface antigens, mainly variant surface antigen (VAR2CSA), that bind to specific receptors, mainly chondroitin sulphate A. In stable transmission settings, the higher malaria risk in primigravidae can be explained by the non-recognition of these surface antigens by the immune system. Recently, placental sequestration has been described also for P.vivax infections. The mechanism of preterm delivery and intrauterine growth retardation is not completely understood, but fever (preterm delivery), anaemia, and high cytokines levels have been implicated.Clinical suspicion of MiP should be confirmed by parasitological diagnosis. The sensitivity of microscopy, with placenta histology as the gold standard, is 60% and 45% for peripheral and placental falciparum infections in African women, respectively. Compared to microscopy, RDTs have a lower sensitivity though when the quality of microscopy is low RDTs may be more reliable. Insecticide treated nets (ITN) and intermittent preventive treatment in pregnancy (IPTp) are recommended for the prevention of MiP in stable transmission settings. ITNs have been shown to reduce malaria infection and adverse pregnancy outcomes by 28-47%. Although resistance is a concern, SP has been shown to be equivalent to MQ and AQ for IPTp. For the treatment of uncomplicated malaria during the first trimester, quinine plus clindamycin for 7 days is the first line treatment and artesunate plus clindamycin for 7 days is indicated if this treatment fails; in the 2(nd) and 3(rd) trimester first line treatment is an artemisinin-based combination therapy (ACT) known to be effective in the region or artesunate and clindamycin for 7 days or quinine and clindamycin. For severe malaria, in the second and third trimester parenteral artesunate is preferred over quinine. In the first trimester, both artesunate and quinine (parenteral) may be considered as options. Nevertheless, treatment should not be delayed and should be started immediately with the most readily available drug.
HubMed – drug
More Drug And Alcohol Rehabilitation Information…