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First pass effect - Wikipedia, the free encyclopedia The first-pass effect (or first-pass metabolism) is a phenomenon of drug metabolism. Some drugs are so extensively metabolized by the liver that only a small amount of unchanged drug may enter the systemic circulation, so the bioavailability of the drug is reduced. Alternative routes of administration (e.g., intravenous, intramuscular, sublingual) avoid the first-pass effect. en.wikipedia.org /wiki/First_pass_effect   (131 words)

Pharmacology to nurses - Metabolism   (Site not responding. Last check: 2007-11-03) The first pass effect can, however, be avoided if the drug is given by another route. Thus, glyceryl trinitrate, when administered sublingually or transdermally, avoids first pass metabolism by the liver and is able to cause a therapeutic effect. First-pass effects may so greatly limit the bioavailability of orally administered drugs that alternative routes of administration must be employed to achieve therapeutically effective blood levels. abdellab.sunderland.ac.uk /Lectures/Nurses/metabolism01.html   (472 words)

Designer Supplements - * Designer Supplements Fat Melting Stack - Fitness First USA First we were scared of fat, then we were scared of carbs, now we realize the importance of a balanced intake of all macronutrients, but we try to avoid processed fats and sugars. Glucokinase is the enzyme involved in the first step of glucose metabolism in the liver and current research indicates that biotin stimulates the synthesis of this enzyme, thereby improving glycemic control and increasing glucose uptake36-38. This effect is yet further reinforced by biotin’s ability to increase ATP synthesis in pancreatic cells40, indicating an increase in the use of glucose in the glycolytic pathway. www.fitnessfirstusa.com /details.asp?item=9592   (10231 words)

Pass Laboratories X150.5 Stereo Power Amplifier reviewed on AudioRevolution.com Nelson Pass is a strong advocate of the concept that simplicity is paramount in producing an amplifier with superior performance. Finally, although the Pass Laboratories X amplifiers do include both balanced and single-ended input connections, I did not have a balanced preamp available at the time of this review, so I was not able to take full advantage of the matched architecture of the X150.5. Through the Pass amplifier, the soundstage goes from very small and intimate to large and wide as the single voice expands to many, and the snaps and clangs of the percussion and keyboards expand the image even more, before it shrinks back into a solid, center-focused small image again. www.avrev.com /equip/passlabsx   (2760 words)

APStracts 8:0143A, 2001.   (Site not responding. Last check: 2007-11-03) In this study, we used a breath-by-breath analysis of 13CO2 to depict the washout of 13CO2 at a high temporal resolution to analyze the extent to which a probable first-pass effect is responsible for the reduced recovery. The area under the first peak resulted in 3.8 ± 1.3% of the total [13C]bicarbonate dose at rest, 11.5 ± 2.9% at moderate exercise (40% "vo2max"), and 16.9 ± 4.0% at intensive exercise (75% "vo2max"). The "loss" of tracer via this first-pass effect must be considered when the results of studies with parenteral administration of [13C]bicarbonate are considered, especially when it is given as a bolus dose and during exercise. www.uth.tmc.edu /apstracts/2001/jap/April/143a.html   (352 words)

GelStat™ Migraine FAQ1   (Site not responding. Last check: 2007-11-03) Our research has shown that many of the active ingredients in feverfew and ginger are destroyed by the “first pass effect” – so while you might have thought you were taking feverfew in the past – it may be that none of the active ingredients were reaching your bloodstream. The “first sign” will vary by migraine and among individuals, but is usually the onset of mild pain that the user has come to identify with the onset of migraine. In the first clinical trial of GelStat Migraine, side effects were reported to be “mild and infrequent.” The most common ‘side effect’, reported only infrequently, concerned the taste of the medication. www.gelstat.com /newfaq1.asp   (577 words)

First pass First pass : the first of two or more planned entries over a specific period oftime (usually one rotation) to harvest timber. First Pass in the First Linac and Arc 1... The main objective of this first pass is to attempt a uniform-first approach for www.mongabay.com /reference/environment/First_pass.html   (269 words)

Evaluation of the first-pass glucuronidation of selected flavones in gut by Caco-2 monolayer model. The importance of the first-pass effect exerted by the intestine is generally regarded to be less than the liver due to the lower protein level and catalytic activity of the drug metabolizing enzymes in gut (12). Table 2: Effect of a UGT inducer on the formation of glucuronide of flavones in the Caco-2 cell (n=3). and Lin, SY., Anti-inflammatory and anti-tumor effects of flavonoids and flavanoids. www.ualberta.ca /~csps/JPPS8(1)/Z.Zuo/flavones.htm   (4499 words)

Do Histamine-2 Receptor Antagonists Influence the Metabolism of Ethanol? -- Levitt 118 (7): 564 -- Annals of Internal ... First pass metabolism of ethanol: an important determinant of blood levels after alcohol consumption. The effect of ranitidine, cimetidine or famotidine on low-dose post-prandial alcohol absorption. Effects of various concomitant medications on gastric alcohol dehydrogenase and the first pass metabolism of ethanol. www.annals.org /cgi/content/full/118/7/564   (1521 words)

Introduction to Effect Files DirectX 8 introduced the concept of Effect Files, a file format allowing for the description of rendering techniques outside of the compiled application, which can be loaded at run-time and applied to objects during rendering. By separating the programming of visual effects from the application code, effect files can potentially become part of the art pipeline, accompanying incoming geometry and associated media with the specifics of how they are to be rendered. Effect parameters are set using Set* methods of the effect class corresponding to different parameter types. www.mvps.org /directx/articles/effect/effect1_1.htm   (1075 words)

Nicotine (PIM) The effect of nicotine declines as it is Nicotine undergoes a large first pass effect during which the liver metabolizes 80% to 90%; to a smaller extent, the lung also is able to metabolize nicotine. Other reported effects of smoking, which do not involve enzyme induction, include reduced diuretic effects of furosemide and decreased cardiac output, and antagonism of the hypotensive effects of propranolol, which may also relate to the normal effects of nicotine. www.inchem.org /documents/pims/chemical/nicotine.htm   (3891 words)

Pharmacokinetics of a Chemoprotective Agent, 2-(Allylthio)pyrazine, after Intravenous and Oral Administration to Rats: ... Huang SM, Huang YC and Chiou WL (1981) Oral absorption and presystemic first-pass effect of chlorpheniramine in rabbits. Kim JH, Kim SH and Lee MG (1997a) Liver and gastrointestinal first-pass effect of azosemide in rats. Nam SY (1998) Molecular pharmacological studies on the radioactive mechanisms and the effects of radioprotective agents: The role of epoxide hydrolase and glutathione S-transferase expression. dmd.aspetjournals.org /cgi/content/full/27/2/221   (4271 words)

HRT-About Estrogen: functions, low levels, ERT, oral vs transdermal Because estrogens have important effects on so many body tissues, it is not surprising that when a woman’s estrogen levels drop (especially when they drop suddenly), there may be negative or potentially negative effects. Oral estrogens seem to have more side effects than estrogens delivered through the skin or the vagina, apparently due to the "first pass" through the liver that occurs when drugs are taken by mouth. Oral estrogens are quickly broken down by the liver, and this "first pass" through the liver seems to be responsible for certain side effects as well as for the positive effects of oral estrogen on cholesterol levels, lowering LDL (the "bad" cholesterol) and raising HDL (the "good" cholesterol). www.project-aware.org /Managing/Hrt/estrogen.shtml   (1234 words)

Anti-first-pass effect compounds (US6124477) Hollander et al, "The Effect of Grapefruit Juice on Cyclosporine and Prednisone Metabolism in Transplant Patients", Clin. First et al, "Concomitant Administration of Cyclosporin and Ketoconazole in Renal Transplant Recipients", The Lancet, Nov. 18, 1198-1200, 1989. Johnston et al, "Effect of Grapefruit Juice on Blood Cyclosporin Concentration", The Lancet, Jul. 8, 346: 122-124, 1995. www.delphion.com /details?pn=US06124477__   (1851 words)

first pass metabolism - General Practice Notebook   (Site not responding. Last check: 2007-11-03) First pass metabolism of drugs can occur in the gut and the liver. The first pass effect of the liver is much reduced if there is shunting; this is much more important than damage to the liver in that it only requires a relatively small amount of functional liver to achieve adequate first pass metabolism. However, cirrhotic patients are apparently more sensitive to some drugs, and this appears to be a systematic effect of the disturbed liver function. www.gpnotebook.co.uk /cache/-1945763815.htm   (145 words)

The Effect of Food on the Relative Bioavailability of Rapidly Dissolving Immediate-Release Solid Oral Products ... The food effect is least likely to occur with rapidly dissolving, immediate-release (IR) drug products containing highly soluble and highly permeable drug substances because absorption of highly soluble and highly permeable drugs is usually pH- and site-independent and thus insensitive to differences in dissolution. In addition, a previous study has shown that the concomitant intake of food had no effect on the area under plasma concentration time curves although the urinary recovery of the drug was higher under fed state than fasting state conditions. The effect is least likely to occur with rapidly dissolving, IR drug products containing highly soluble and highly permeable drug substances because absorption of highly soluble and highly permeable drugs is usually pH- and site-independent and thus insensitive to differences in dissolution. pubs.acs.org /cgi-bin/sample.cgi/mpohbp/2004/1/i05/html/mp0499407.html   (3949 words)

Pharmacokinetics And Pharmacodynamics Of Antibacterial Agents In Pediatrics: A Practical Approach This presystemic transformation by the intestine and liver is known as first-pass effect. In some clinical situations, a rapid therapeutic effect is desired and a loading dose is recommended (e.g., pediatric patients with altered renal function or larger volumes of distribution). The post-antibiotic effect (PAE) is another important pharmacodynamic phenomenon, which is the persistent suppression of bacterial growth after antibiotic concentrations have fallen below the MIC for the infecting bacteria. www.dcmsonline.net /jax-medicine/1998journals/august98/pediatric.htm   (3809 words)

Pharmacokinetics and Biopharmaceutics First-pass effect: This is an extremely important phenomenon to understand. The consequence of the first-pass effect is that the fraction of drug reaching the systemic circulation is substantially reduced. Name two enteral and two topical routes of administration that avoid the first pass effect. www.uiowa.edu /~c046138/tut-route.htm   (642 words)

Guidance for Industry:  Food-Effect Bioavailability and Fed Bioequivalence Studies Food effect BA studies are usually conducted for new drugs and drug products during the IND period to assess the effects of food on the rate and extent of absorption of a drug when the drug product is administered shortly after a meal (fed conditions), as compared to administration under fasting conditions. In these cases, the relative direction and magnitude of food effects on formulation BA and the effects on the demonstration of BE are difficult, if not impossible, to predict without conducting a fed BE study. An absence of food effect on BA is indicated when the 90 percent CI for the ratio of population geometric means between fed and fasted treatments, based on log-transformed data, is contained in the equivalence limits of 80-125 percent for AUC www.fda.gov /cder/guidance/5194fnl.htm   (3175 words)

Effect of Sodium Thiosulfate on Cisplatin Removal With Complete Hepatic Venous Isolation and Extracorporeal Charcoal ... The mechanisms for chemoprotective effect of STS are controversial. Effect of sodium thiosulfate on the pharmacokinetics and toxicity of cisplatin. First evidence of otoprotection against carboplatin-induced hearing loss with a two-compartment system in patients with central nervous system malignancy using sodium thiosulfate. www.annalssurgicaloncology.org /cgi/content/full/8/5/449   (4049 words)

CV Renal - Part 2 Drug Effects:  Heart receptors are primarily beta-1, which are responsible for the conduction effects of the conduction system. Their most dramatic antianginal effects, however, are secondary to their effects on myocardial contractility and the smooth muscle tone of peripheral and coronary arteries. Drug Effects:     The effects of the calcium channel blockers are mostly limited to the CV system. www.ilstu.edu /~ddwilso2/nur433/CV_Renal_Part_2.htm   (1720 words)

PHARMACOLOGY During the first pass through the liver, a fraction of the drug (in some cases nearly all) can be metabolized to an inactive or less active derivative. A good way to tell if a drug has a significant first pass effect is to compare oral with IV doses. If the oral dose is large, compared to the IV dose, it probably has extensive first pass effect. www.msu.edu /~prinsen/page3.13.htm   (375 words)

Absorption Systems: In vitro studies on enhancing effect of sodium glycocholate on transbuccal permeation of morphine ... Ponchel G, et al., In vitro studies on enhancing effect of sodium glycocholate on transbuccal permeation of morphine hydrochloride. In this study, the enhancing effect of sodium glycocholate (GC) used at 10 mM and 100 mM concentrations on permeation of morphine hydrochloride (MPH) across the porcine buccal mucosa was studied in vitro. Furthermore, in conjunction with its permeation, accumulation of GC in the tissue with time was also studied in order to elucidate the relationship between GC and enhanced mucosal permeation of the drug. www.absorption.com /Site/References/Default.aspx?ID=46   (298 words)

First-pass effect of an intravenous bolus of [13C]bicarbonate displayed breath-by-breath -- Roecker et al. 90 (6): 2181 ... A first-pass effect of the venous blood through the lungs was supposed by Armon et al. effect of the passage of the substance through the lungs (7). Hatched areas under the excessive peaks are interpreted as first-pass effect in the lungs. www.jap.org /cgi/content/full/90/6/2181   (3358 words)

Pass a Drug Test - Urine Drug Test - Hair Drug Test - Saliva Drug Test with our Proven Drug Testing Solutions   (Site not responding. Last check: 2007-11-03) Passing drug tests have never been so easy with our drug testing products. Passing a drug test doesn't have to be complicated or stressful. Testclear has been helping people pass drug test for 7 years providing proven drug testing solutions to help people pass urine drug tests, pass hair drug tests, and pass saliva drug tests. www.pass-drug-test.info /how-to-pass-drug-texts   (418 words)

PHAR 4634 - Chapter 7 Page 3 First pass - The liver is by-passed thus there is no loss of drug by first pass effect for buccal administration. If any is swallowed that portion must be treated as an oral dose and subject to first pass metabolism. By-pass liver - Some of the veins draining the rectum lead directly to the general circulation, thus by-passing the liver. www.boomer.org /c/p1/Ch07/Ch0703.html   (243 words)

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