Drugs online research references
Clin Ther. 1992 May-Jun;14(3):409-17.
Conversion from glipizide to glyburide: a prospective cost-impact survey.
Alexis G, Henault R, Sparr HB.
Pharmacy Service, Veterans Administration Medical Center, Brockton, Massachusetts.
Despite extensive clinical experience with second-generation oral hypoglycemic agents, the relative dosing equivalence of glyburide and glipizide remains controversial. A prospective survey was conducted to determine the feasibility and cost of converting noninsulin-dependent diabetic patients from glipizide to glyburide. A total of 211 patients previously stabilized on glipizide were converted to glyburide and returned to their respective clinics at least once during the following six months. The mean daily dose (+/- SD) of glipizide before conversion was 18.7 +/- 12.32 mg; the mean daily dose of glyburide after seven months was 9.9 +/- 6.52 mg (P less than 0.001, paired t test). Glyburide was well tolerated. The conversion program appeared to be successful and resulted in a 47% reduction in the mean daily dose after conversion from glipizide to glyburide, which, in turn, conferred a 43% savings in the projected yearly expenditures for second-generation oral hypoglycemics.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1638582&dopt=Abstract
J Pharmacol Exp Ther. 1991 Nov;259(2):566-73.
Characterization of sulfonylurea receptors and the action of potassium channel openers on cholinergic neurotransmission in guinea pig isolated small intestine.
Zini S, Ben-Ari Y, Ashford ML.
Laboratoire de Neurobiologie et Physiopathologie du Developement, Institut National de la Sante et de la Recherche Medicale U29, Paris, France.
Specific binding sites for [3H]glibenclamide, a potent ATP-sensitive K+ channel blocker, have been characterized in the isolated guinea pig longitudinal muscle-myenteric plexus preparation. The Scatchard plot of the saturation isotherm was curvilinear and revealed two binding sites, one of high affinity (Kd = 0.42 nM; maximum binding site = 156 fmol/mg of protein), the other of low affinity (Kd = 83 nM; maximum binding site = 3100 fmol/mg of protein). Displacement experiments in the presence of various sulfonylureas showed the same order of potency for the two binding sites (glibenclamide greater than gliquidone greater than glipizide glibornuride greater than chlorpropamide greater than tolbutamide). The K+ channel opener RP 49356 (but not diazoxide or cromakalim) displaced the [3H] glibenclamide with an IC50 of 4.8 microM. The effects of the K+ channel openers diazoxide, RP 49356, cromakalim and its two optical isomers BRL 38226 and BRL 38227 were also studied on the electrically induced contractions of isolated guinea pig small intestine. These compounds produce an inhibition of neurally evoked twitch height with pD2 values of 4.5 to 6.2 (BRL 38227 greater than cromakalim greater than RP 49356 greater than diazoxide, whereas BRL 38226 was practically ineffective). The effects of cromakalim and RP 49356 were antagonized competitively by glibenclamide (pA2 = 7.2) and other sulfonylureas, suggesting they act on ATP-sensitive K+ channels. Affinities of the sulfonylureas obtained from concentration-response curves to cromakalim on electrically induced contractions are better correlated with the IC50 value corresponding to the low affinity binding site than to the high affinity.(ABSTRACT TRUNCATED AT 250 WORDS)
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1658303&dopt=Abstract
Proc Soc Exp Biol Med. 1991 Jan;196(1):76-82.
Calcium-stressed erythrocyte membrane structure and function for assessing glipizide effects on transglutaminase activation.
Redding GS, Record DM, Raess BU.
Department of Pharmacology, Indiana University School of Medicine, Evansville 47732.
A proposed mechanism of action of hypoglycemic sulfonylureas is the prevention of transglutaminase-mediated endocytosis of insulin receptors. When activated by high levels of intracellular calcium, transglutaminase (TG) catalyzes the cross-linking of intracellular proteins to membrane proteins and modifies membrane structure and function. This study examined the effects of the sulfonylurea glipizide on TG activity in an erythrocyte model by assessing various membrane ATPase activities and high molecular weight protein polymer formation using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. To activate TG, red blood cells were exposed to 1 mM intracellular Ca2+ using 10(-5) M Ca2(+)-ionophore A23187. In Ca2(+)-stressed cells, calmodulin stimulation (0.1 micrograms/ml) of (Ca2+ + Mg2+)-ATPase was decreased to 21.2% of control activity. Increasing concentrations of calmodulin (0.1-3.0 micrograms/ml) could not overcome the inhibitory effects of TG on the (Ca2+ + Mg2+)-ATPase in Ca2(+)-stressed cells with or without glipizide. An increased Ca2+ sensitivity of calmodulin-independent (Ca2+ + Mg2+)-ATPase due to Ca2+ stress was seen in all Ca2(+)-stressed cells even in the presence of 1 mM glipizide. Structural changes were observed in the form of high molecular weight polymer formation. Cells exposed to high Ca2+ and glipizide (3 x 10(-5)-10(-3) M) showed no improvement in ATPase activity or protection from protein cross-linking compared with cells without the drug. We conclude that in this model glipizide fails to inhibit TG induced protein cross-linking and does not prevent the decrease in (Ca2+ + Mg2+)-ATPase activation in Ca2(+)-stressed red blood cells. This finding considerably weakens the proposal that sulfonylureas act by inhibiting TG activity.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1670593&dopt=Abstract
online pharmacies ||
Hair Million herbal formula for hair loss and hair growth ||
Amoxicillin ||
Tramadol ||
Paxil ||
Rx Drugs USA, Prescription Drugs Online Pharmacy ||
Zithromax ||
online pharmacy ||
Antibiotics and prescription medications online literature ||
Antibiotics