Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0013395 (dyspepsia)
 4,879 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serotonin (5-hydroxytryptamine; 5-HT) is found in the enteric nervous system where it has been implicated in controlling gastrointestinal motor function. A number of receptor or recognition sites have been identified in the gut, but recently most attention has focused on the 5-HT3 and 5-HT4 receptors. The functional role of the 5-HT3 receptor remains incompletely understood, but it is probably involved in the modulation of colonic motility and visceral pain in the gut. A number of selective 5-HT3 antagonists have been developed including ondansetron, granisetron, tropisetron renzapride and zacopride. While the substituted benzamide prokinetics (for example, metoclopramide, cisapride) also block 5-HT3 receptors in high concentrations, their prokinetic action is believed to be on the basis of their agonist effects on the putative 5-HT4 receptor. Some 5-HT3 antagonists have 5-HT4 agonist activity (for example, renzapride, zacopride) and others do not (for example, ondansetron, granisetron), while tropisetron in high concentrations is a 5-HT4 antagonist. Based on the pharmacological data, it has been suggested that specific 5-HT antagonists and agonists may prove to be beneficial in a number of gastrointestinal disorders including the irritable bowel syndrome, functional dyspepsia, non-cardiac chest pain, gastrooesophageal reflux and refractory nausea. In this review, the rationale for the use of these compounds is discussed, and the available experimental evidence is summarized.
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PMID:Review article: 5-hydroxytryptamine agonists and antagonists in the modulation of gastrointestinal motility and sensation: clinical implications. 160 46

Three major areas of medicine are identified in which there is a need for new antiemetic drugs. These are the nausea and vomiting arising from gastrointestinal motility disturbances (functional dyspepsia, diabetic neuropathy, classical migraine), the sickness evoked by abnormal motion, and the severe emesis experienced by cancer patients as a result of certain cytotoxic therapies. For gastrointestinal-related nausea, selective stimulants of gut motility are suggested to form the basis for a new type of antiemetic therapy. In motion sickness, there has been progress in the understanding of the illness, but little advance in the development of new drugs that selectively prevent this type of sickness. In cancer chemo- and radio-therapy, the discovery that selective 5-HT3 (5-HT, 5-hydroxytryptamine) receptor antagonists can prevent severe cytotoxic-evoked emesis now promises to radically change the type of antiemetic therapy given to these patients. This type of antiemetic compound and the pharmacology of the new 5-HT3 receptor antagonists are, therefore, discussed in detail.
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PMID:New antiemetic drugs. 217 55

Citalopram, a selective 5-HT uptake inhibitor with antidepressant properties, was assessed in three studies in 12 healthy subjects using a battery of EEG, psychological, subjective and symptomatic measures. Study A involved the administration of citalopram, 20 mg and 40 mg, amitriptyline 50 mg and placebo in single dose using a balanced cross-over design. The test battery was applied before, and 1 and 3 h after each drug. Citalopram decreased slow-wave EEG activity whereas amitriptyline increased power in most EEG wavebands. Citalopram increased tapping rate and symbol copying whereas amitriptyline impaired these and other psychomotor tasks. Subjectively, amitriptyline was much more sedative than citalopram and produced more complaints of dry mouth. Study B comprised the administration of citalopram in the usual clinical dose of 40 mg, amitriptyline in the low clinical dose of 75 mg and placebo, each given for 9 nights using a balanced cross-over design. The test battery was applied on the first morning (pre-drug) and on the morning after the last nightly dose. None of the physiological tests showed any drug effects. Subjectively, citalopram was associated with feelings of shaking, nausea, loss of appetite and physical tiredness; amitriptyline produced feelings of shaking, nausea, loss of appetite, dryness of mouth, irritability, dizziness and indigestion; in general, amitriptyline effects were more marked than those of citalopram. Plasma samples were taken on the last day and plasma concentrations of both drugs and their metabolites were found to be in the expected range for the regimens used.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The effects of citalopram in single and repeated doses and with alcohol on physiological and psychological measures in healthy subjects. 346 75

A greater understanding of the various serotonin receptor subtypes has led to a clearer appreciation of the role of serotonin in gastrointestinal motility, sensation and secretion. Serotonin is definitely involved in the aetiopathogenesis of cisplatin-induced emesis and carcinoid diarrhoea. The application of serotonergic drugs in clinical therapeutics for gut disturbances is presently dominated by the use of 5-HT3 antagonists for acute chemotherapy-induced nausea and vomiting, and the use of substituted benzamides which are 5-HT4 agonists stimulating gut motor function through 5-HT4 neuronal receptors. The best-studied 5-HT4 agonist is cisapride, which has been shown to stimulate motility at several levels of the gut. Cisapride is approved for healing and maintenance treatment of reflux oesophagitis and is used in several countries for the alleviation of symptoms consistent with regional stasis, from dyspepsia to constipation. Carcinoid diarrhoea is a prototypic disease associated with deranged serotonin metabolism, and a rationale for using 5-HT3 or 5-HT4 antagonists is based on the recent appreciation of the important role of impaired gut motor function in carcinoid diarrhoea. In the future, greater understanding of the serotonin receptor subtypes and their role in gut disorders may lead to novel approaches to alleviate increased visceral perception of functional gastrointestinal disorders, to correct changes in colonic capacitance, or to alter gastrointestinal motility that contributes to diarrhoea or constipation. However, at the present time, it must be stressed that these uses are still at an experimental stage and that careful validation and proper controlled studies are still required.
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PMID:Drugs affecting serotonin receptors. 794 60

Gastrointestinal prokinetics promote or increase the coordination of the gut wall contractions leading to enhancement of propulsive motility and, consequently, caudal displacement of luminal contents. Currently, they are considered drugs of choice for the treatment of upper gastrointestinal tract functional motor disorders such as those associated with gastrooesophageal reflux disease, chronic dyspepsia, gastroparesis (idiopathic or secondary to other diseases) and acute or chronic idiopathic intestinal pseudo-obstruction. The aim of the present review is to give an outline of the pharmacology of currently available prokinetics and of novel drugs endowed with gastrointestinal prokinetic action that require further pharmacological and/or clinical testing. The novel drugs include recent generations of benzamide and non-benzamide 5-HT4 receptor agonists, motilin receptor agonists, and inhibitors of nitric oxide synthase. Furthermore, based on our improved knowledge of the role of 5-HT in emesis and gastrointestinal motility, the therapeutic potential of potent mixed 5-HT4 agonists--5-HT3 antagonists in the control of cytotoxic-drug-induced emesis and associated gut motor disturbances will be discussed. Lastly, a section of this review deals with the colon as a possible target for the action of prokinetics.
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PMID:Recent advances in the pharmacology of gastrointestinal prokinetics. 893 12

Several serotonin (5-HT) receptor subtypes have been defined by pharmacological responses to selective agonists and antagonists and by pathways of receptor-effector coupling. Using molecular techniques, additional receptor subtypes have been described. 5-HT receptors are prevalent in the central nervous system and gut and participate in induction of emesis. 5-HT3 antagonists are used to prevent emesis from cancer chemotherapy and also demonstrate efficacy in radiation-induced nausea, postoperative nausea, hyperemesis gravidarum, and nausea and vomiting with the acquired immunodeficiency syndrome. 5-HT4 agonists exhibit prokinetic properties in nauseated patients with gastroparesis and functional dyspepsia. Conversely, 5-HT4 antagonists have antiemetic activity in some experimental models. The 5-HT1D receptor agonist sumatriptan reduces emesis with migraine headaches and in cyclic vomiting syndrome, most likely via action on central nervous system sites. In other models, 5-HT1A and 5-HT2A/5-HT2C agonists exhibit antiemetic properties. The utility of 5-HT receptor ligands in treating emesis is the subject of active investigation.
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PMID:Serotonin receptor physiology: relation to emesis. 1049 49

Drug development for functional gastrointestinal disorders is complex. These conditions involve central and peripheral physiological changes, together with psychological factors. Methodological problems have included a poor appreciation of the physiological and psychological correlates of patients' symptoms, a lack of animal models of proven relevance, and safety issues. Government, patient pressure groups and the Internet can also influence a drug's success. Most recent interest has focused on the serotonin (5-HT) modifying drugs. Cisapride has been withdrawn in some countries because of concerns related to QT prolongation and cardiac arrhythmias. The 5-HT3 antagonists, developed to modify visceral sensation, have caused constipation; alosetron, also withdrawn, caused ischaemic colitis. The 5-HT4 agonists induce peristalsis; tegaserod and prucalopride, both delayed in their development due to issues of safety and efficacy, benefit patients with 'constipation-predominant' irritable bowel syndrome or idiopathic constipation. 5-HT1 agonists improve impaired gastric accommodation and symptoms in patients with functional dyspepsia. Antidepressants also affect serotonin metabolism. Previous examples of success in this area involved drugs targeted at peripheral receptors mediating motor function or secretion. Modification of sensory function is a much more challenging objective. The experience with serotonin modifying drugs has been mixed, and some important lessons are there to be learnt.
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PMID:Review article: the complexity of drug development for irritable bowel syndrome. 1187 86

Nonulcer dyspepsia is a common condition in clinical practice. It is a heterogeneous disorder, and no single therapeutic agent is effective in all patients. The treatment of nonulcer dyspepsia is still dissatisfactory. Eradication of Helicobacter pylori organisms has a limited role and little effect. Antisecretory therapy has a modest effect in alleviating symptoms. Prokinetic agents may be effective, but selection bias in the trials performed to date may exaggerate their benefit. Partial 5-HT(4) agonists stimulate gastric emptying and may also affect gastric accommodation. They are promising but need further study. Data are limited on 5-HT(3) antagonists and hypnotherapy. New treatment approaches are necessary for this common and often chronic condition.
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PMID:Nonulcer dyspepsia. 1244 Oct 34

Functional dyspepsia is a clinical syndrome defined by chronic or recurrent pain or discomfort in the upper abdomen of unknown origin. Although generally accepted, investigators differently interpret this definition and clinical trials are often biased by inhomogeneous inclusion criteria. The poorly defined multifactorial pathogenesis of dyspeptic symptoms has hampered efforts to develop effective treatments. A general agreement exists on the irrelevant role played by Helicobacter pylori in the pathophysiology of functional dyspepsia. Gastric acid secretion is within normal limits in patients with functional dyspepsia but acid related symptoms may arise in a subgroup of them. Proton pump inhibitors appear to be effective in this subset of patients with dyspepsia. Non-painful dyspeptic symptoms are suggestive of underlying gastrointestinal motor disorders and such abnormalities can be demonstrated in a substantial proportion of patients. Postprandial fullness and vomiting have been associated with delayed gastric emptying of solids, and early satiety and weight loss to postcibal impaired accommodation of the gastric fundus. Prokinetics have been shown to exert beneficial effects, at least in some patients with dyspepsia. In contrast, drugs enhancing gastric fundus relaxation have been reported to improve symptoms, although conflicting results have also been published. An overdistended antrum may also generate symptoms, but its potential pathogenetic role and the effects of drugs on this abnormality have never been investigated formally. Visceral hypersensitivity plays a role in some dyspeptic patients and this abnormality is also a potential target for treatment. Both chemo- and mechanoreceptors can trigger hyperalgesic responses. Psychosocial abnormalities have been consistently found in functional digestive syndromes, including dyspepsia. Although useful in patients with irritable bowel syndromes (IBS), antidepressants have been only marginally explored in functional dyspepsia. Among the new potentially useful agents for the treatment of functional dyspepsia, serotonin 5-HT(4) receptor agonists have been shown to exert a prokinetic effect. Unlike motilides, 5-HT(4) receptor agonists do not appear to increase the gastric fundus tone and this may contribute to improve symptoms. 5-HT(3) receptor antagonists have been investigated mainly in the IBS and the few studies performed in functional dyspepsia have provided conflicting results. Also, kappa-opioid receptor agonists might be useful for functional digestive syndromes because of their antinociceptive effects, but available results in functional dyspepsia are scanty and inconclusive. Other receptors that represent potential clinical targets for antagonists include purinoceptors (i. e., P2X2/3 receptors), NMDA receptors (NR2B subtype), protease-activated receptor-2, the vanilloid receptor-1, tachykinin receptors (NK(1)/NK(2)) and cholecystokinin (CCK)(1) receptors.
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PMID:New developments in the treatment of functional dyspepsia. 1267 73

Novartis has developed and launched tegaserod, an aminoguanidine indole 5-HT(4) receptor partial agonist, for the potential treatment of constipation-predominant irritable bowel syndrome (IBS) [286804], [311514] and other functional GI disorders, such as gastroesophageal reflux disease (GERD), chronic constipation and functional dyspepsia [342937], [362853]. It was launched in Mexico for IBS in July 2001 [416879] and in the Czech Republic, Venezuela and Colombia by October 2001. By this time, the product had also been approved in Switzerland [427419]. In September 2001, launch of the product for GERD, chronic constipation and functional dyspepsia was expected after 2003 [422828]; later in October 2001, the launch dates for the latter two indications were anticipated for 2004 [427419], [431614]. In December 2000, Merrill Lynch predicted sales of SFr 150 million in 2001, rising to SFr 612 million in 2004, larger than the September 2000 predictions of SFr 120 million in 2001 rising to SFr 378 million in 2004 [394812], [383742]. Later in February 2001, Merrill Lynch predicted sales of SFr 150 million in 2001 rising to SFr 785 million per annum in 2005, assuming a US launch during the third quarter of 2001 [411704]. Following the withdrawal of the MAA and then the rejection of tegaserod's NDA by the FDA, in June 2001, Merrill Lynch progressively revised its 2005 sales forecasts from SFr 1.1 billion to SFr 950 million and then to SFr 375 million [422783]. In June 2001, Merrill Lynch also suggested that there was a significant possibility that tegaserod would never reach the market. In August 2001, Deutsche Bank estimated sales of SFr 200 million in 2004 and SFr 550 million in 2005 [422674]. Analysts at Credit Suisse predicted in October 2001, that there was only a three in ten chance that tegaserod would ever reach a major market following the issuance of a 'non-approvable' letter by the FDA in June 2001. They predicted sales of SFr 5 million in 2001, rising to SFr 325 million in 2005 [426409].
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PMID:Tegaserod (Novartis). 1286 78


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