Drugs online research references
J Neurochem. 1999 Mar;72(3):1117-24.
Antidepressants noncompetitively inhibit nicotinic acetylcholine receptor function.
Fryer JD, Lukas RJ.
Division of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona 85013, USA.
Nicotinic acetylcholine receptors (nAChRs) are diverse members of the neurotransmitter-gated ion channel superfamily and play critical roles in chemical signaling throughout the nervous system. The present study establishes for the first time the acute functional effects of sertraline (Zoloft), paroxetine (Paxil), nefazodone (Serzone), and venlafaxine (Effexor) on two human and one chick nAChR subtype. This study also confirms previous findings of nAChR functional block by fluoxetine (Prozac). Function of human muscle-type nAChR (alpha1/beta gammadelta) in TE671/RD cells, human autonomic nAChR (alpha3/beta4alpha5 +/- beta2) in SH-SY5Y neuroblastoma cells, or chick V274T mutant alpha7-nAChR heterologously expressed in native nAChR-null SH-EP1 epithelial cells was measured using 86Rb+ efflux assays. Functional blockade of human muscle-type and autonomic nAChRs is produced by each of the drugs in the low to intermediate micromolar range, and functional blockade of chick V274T-alpha7-nAChR is produced in the intermediate to high micromolar range. Functional blockade is insurmountable by increasing agonist concentrations at each nAChR subtype tested for each of these drugs, suggesting noncompetitive inhibition of nAChR function. These studies open the possibilities that nAChR subtypes in the brain could be targets for therapeutic antidepressants and could play roles in clinical depression.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10037483&dopt=Abstract
word match zoloft online literature
Brain Res. 1996 Oct 14;736(1-2):82-90.
Effects of tianeptine, sertraline and clomipramine on brain serotonin metabolism: a voltammetric approach in the rat.
Marinesco S, Poncet L, Debilly G, Jouvet M, Cespuglio R.
Departement de Medecine Experimentale, Universite Claude Bernard, Lyon, France.
Tianeptine is a substance enhancing the serotonir uptake while sertraline and clomipramine inhibit it. By means of 5-hydroxyin-doleacetic acid (5-HIAA) voltammetric measurements, this study investigated their influence on serotonin metabolism which depends mainly upon the activity of monoamine oxidase type A. After tianeptine injection the 5-HIAA signal increased by about 60%. This effect was maintained when the animals were pre-treated with MDL 72145 (an inhibitor of monoamine oxidase type B) but reduced when clorgyline (an inhibitor of monoamine oxidase type A) was administered after tianeptine. Administration of sertraline or clomipramine reduced the 5-HIAA signal by about 30-50%, whether the animals were pre-treated with MDL 72145 or not. It is to be concluded that tianeptine, sertraline and clomipramine can regulate the 5-HT fraction present in the synaptic cleft, not only by acting at the level of the serotoninergic neurons, but also by favoring or reducing the access of the amine to monoamine oxidase type A which is synthesized within non-serotoninergic neurons and glial cells.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8930312&dopt=Abstract
word match zoloft online literature
Clin Pharmacol Ther. 1996 Nov;60(5):512-21.
The disposition of fluoxetine but not sertraline is altered in poor metabolizers of debrisoquin.
Hamelin BA, Turgeon J, Vallee F, Belanger PM, Paquet F, LeBel M.
School of Pharmacy, Universite Laval, Quebec Heart Institute, Laval Hospital, Sainte-Foy, Canada.
BACKGROUND: Substrates and inhibitors of the cytochrome P450 isozyme CYP2D6 have overlapping structural characteristics. Two prototype serotonin uptake inhibitors, sertraline and fluoxetine, share these structural criteria and have been identified as potent inhibitors of CYP2D6 in vitro. The current study was undertaken to investigate whether genetically determined CYP2D6 activity alters the disposition of sertraline or fluoxetine or both. METHODS: Single doses of sertraline (50 mg) and fluoxetine (20 mg) were administered successively to 20 young men with high (extensive metabolizers; n = 10) and low (poor metabolizers; n = 10) CYP2D6 activity. Blood and urine samples were collected for 5 to 7 half-lives and sertraline, desmethylsertraline, fluoxetine, and norfluoxetine were determined by GC and HPLC techniques. RESULTS: Poor metabolizers had significantly greater fluoxetine peak plasma concentrations (Cmax; increases 57%), area under the concentration versus time curve (AUCzero-->infinity; increases 290%), and terminal elimination half-life (increases 216%) compared with extensive metabolizers. The total amount of fluoxetine excreted in the urine during 8 days was almost three times higher in poor metabolizers than in extensive metabolizers (719 versus 225 micrograms; p < 0.05), whereas the total amount of norfluoxetine excreted in urine of poor metabolizers was about half of that of extensive metabolizers (524 versus 1047 micrograms; p < 0.05). Norfluoxetine Cmax and AUCzero-->t were significantly smaller in poor metabolizers (decreases 55% and decreases 53%, respectively), and the partial metabolic clearance of fluoxetine into norfluoxetine was 10 times smaller in this group (4.3 +/- 1.9 versus 0.4 +/- 0.1 L/hr; p < 0.05). No significant differences between extensive and poor metabolizers were found for sertraline and desmethylsertraline pharmacokinetics. CONCLUSION: These data indicate that poor metabolizers accumulate fluoxetine but not sertraline and that CYP2D6 plays an important role in the demethylation of fluoxetine but not of sertraline.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8941024&dopt=Abstract
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