Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0042963 (vomiting)
 31,883 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The in vivo neurophysiological interactions of the non-competitive NMDA receptor antagonist MK801 with the High Pressure Neurological Syndrome have been investigated in the primate Papio anubis. A hyperbaric chamber was used to achieve environmental pressures of 61 ATA (atmospheres absolute) over a period of 5 hr. Eight animals underwent 2 compressions each, one following pretreatment with 0.03 mg/kg (i.v.) MK801, the other a control. Half of the animals received MK801 on their first exposure. Mild signs of the high pressure neurological syndrome, e.g. paw and limb tremor were first observed between 10 and 20 ATA and more severe signs, e.g. whole body tremor, myoclonus and vomiting, appeared after 50 ATA. The onset pressures for the various signs were increased by 10-17 ATA when the animals received MK801 (P = 0.06) and the severity of the signs, over the whole range of pressures at which they appeared, was significantly reduced (P less than 0.001). Additional experiments showed that MK801 afforded considerable protection, at pressures up to 81 ATA, but doses larger than those used for the main experiment produced signs of tranquilisation and sedation. Changes in the EEG were observed in channels associated with the frontal, parietal and occipital regions. Amplitude and frequency spectra were calculated and trends with pressure in the 4 conventional wavebands were analysed. The most striking change was a decrease in amplitude of delta waves (P less than 0.001), which was ameliorated by MK801 (P less than 0.001).
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PMID:The effects of MK801 on the high pressure neurological syndrome in the baboon (Papio anubis). 225 85

Dextrorphan HCl (Ro 01-6794/706) is an NMDA receptor antagonist with clinical potential for administration in an elderly population of acute ischemic stroke patients. In vivo experience with such patients demonstrated a consistent pharmacologic effect/adverse experience profile that is typical of an NMDA receptor antagonist (e.g., nystagmus, nausea, vomiting, agitation, somnolence, hallucinations and hypertension). For the most part, these pharmacologic effects were mild to moderate in severity; short-lived; reversible; not life-threatening and subjectively tolerated. The most serious pharmacologic effect produced by dextrorphan administration was hypotension, which occurred within a well-defined window of 90 minutes from the start of the loading dose infusion in patients who received 200 mg/hr or greater loading dose infusions. In all cases it was reversible without neurologic sequelae. Careful review of demographic and pharmacokinetic parameters did not demonstrate any overriding factor(s) to the production of hypotension other than the rate of the loading dose infusion. Severe hypotension, severe decreased levels of consciousness and respiratory depression should not be generally expected at loading doses less than 200 mg/hr. In summary, dextrorphan can be safely given to an elderly population of ischemic stroke patients as a loading dose rate below 200 mg/hr and as a maintenance dose rate between 50-90 mg/hr for 24 hours when patients are monitored carefully for pharmacologic effects.
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PMID:Safety, tolerability and pharmacokinetics of the N-methyl-D-aspartate antagonist Ro-01-6794/706 in patients with acute ischemic stroke. The Dextrorphan Study Group and Hoffmann-La Roche. 748 11

According to the hypothesis implying that the main mechanism underlying opiate addiction is the blockade by opiates of NMDA receptor functions and subsequent upregulation and supersensitivity of the receptors, noncompetitive NMDA receptor blocker dextromethorphan (DM) has been successfully used in the heroin addict treatment. As the stimulation of NMDA receptors modulates the release of neurotransmitters and hormones such as NE, D, ACh, GH, LH, LSH, ACTH etc., all of which have been found responsible for the manifestation of abstinence syndrome signs including craving and neuronal death by excessive stimulation of NMDA receptors, the incomplete blockade of the NMDA receptors minimizes the intensity of the abstinence syndrome and provides the downregulation of the receptors. In the present study, tizanidine (TIZ), which inhibits the release of endogenous excitatory aminoacids by the agonistic activity on alpha 2-adrenoreceptors, was combined with DM to obtain further benefits. Forty-four male and three female heroin addicts were the subjects of the study. Their daily mean heroin intake was about 2.28 g street heroin. The main duration of heroin use was approximately 3.4 years. Two to three hours after abrupt withdrawal, the outpatients were given 15 mg DM every hour, 25 or 50 mg chlorpromazine (CPZ) + 4 mg TIZ every six hours and 10 mg diazepam + 10 mg hyoscine N-butyl Br + 250 mg dipyrone every six hours three hours following CPZ. The addicts were controlled twice a day. Yawning, rhinorrhea, perspiration, piloerection, restlessness, insomnia, emesis, diarrhea, craving, rejection of smoking and pupils were observed and/or questioned. Two of the 47 outpatients took heroin on the first days.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The combination of tizanidine markedly improves the treatment with dextromethorphan of heroin addicted outpatients. 771 85

Glutamate may be a key transmitter in the emetic reflex arc. The present investigation focussed on the involvement of the NMDA subtype of glutamate receptors in cisplatin-induced emesis. Ferrets were injected with cisplatin (10 mg/kg i.v.) and either of the non-competitive NMDA receptor antagonists dextromethorphan or memantine, or the competitive receptor antagonist CGS 19755. In order to determine whether there is a synergism between NMDA blockers and 5-HT3 receptor antagonists, a submaximal dose of granisetron (0.05 mg/kg) was given alone or in combination with either dextromethorphan or memantine. The latency for the onset of emesis as well as the total number of vomits and retches over 3 hr were determined. In controls, the latency for emesis was 73 +/- 6 min and the total number of vomits and retches 143 +/- 17. The corresponding figures for animals treated with dextromethorphan, 10 and 20 mg/kg, were 89 +/- 19 min (p > 0.05) and 50 +/- 17 (p = 0.008), and 113 +/- 18 min (p > 0.05) and 22 +/- 9 (p = 0.004), respectively. At 10 mg/kg, dextromethorphan failed to enhance the antiemetic effect of granisetron which by itself provided 90% inhibition. While memantine (2.5 or 5.0 mg/kg) did not have an effect per se, it tended to reduce the antiemetic effect of granisetron. CGS 19755 (10 mg/kg) provided a partial protection against cisplatin-induced emesis (latency: 111 +/- 23, number of vomits and retches 30 +/- 11). None of the NMDA receptor antagonists was free of behavioural effects (e.g. some sedation) at antiemetic doses. It is concluded that NMDA receptor antagonists may afford protection against cisplatin-induced emesis but the specificity of this effect is uncertain since it may relate to general CNS depression.
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PMID:Effects of N-methyl-D-aspartate receptor antagonists on cisplatin-induced emesis in the ferret. 879 10

The preemptive use of analgetics makes it possible to influence sensitization proceedings caused by a trauma. Various mechanisms are effective in central pain treatment. The NMDA receptor plays an important role. The investigation presented was to examine whether an intraoperative combination of analgetics with different points of contact leads to improved postoperative analgesia. Altogether 39 female patients who had to undergo a gynaecological laparotomy were examined. Three groups of 13 patients were randomly formed. In addition to usual general anaesthesia, the patients of group one received 0.5 mg/kg bodyweight ketamine racemate before the skin incision and thereafter 10 micrograms/kg/min ketamine infusion continuously until peritoneum closure and then sodium chloride 0.9% as a placebo after the final skin suture. The patients of group two received placebos before the skin incision and intraoperatively and 0.5 mg/kg bodyweight ketamine after the last skin suture. In group three the patients received placebos at all three points of time. Analgetics consumption, pain intensity, awakening reaction, vital parameters as well as psychomimetic side-effects and nausea/vomiting were listed postoperatively. Between the groups no differences were found regarding postoperative analgetics consumption. In addition, the pain intensity showed no differences regarding an improved postoperative analgesia through the combination of analgetics with different points of contact. The intraoperative combination of ketamine and alfentanil does not lead to a reduction of postoperative pain. No preemptive analgesia is clinically provable.
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PMID:[Preemptive effects caused by co-analgesia with ketamine in gynecological laparotomies?]. 1047 98

Excitotoxicity is thought to be a major mechanism in many human disease states such as ischemia, trauma, epilepsy and chronic neurodegenerative disorders. Briefly, synaptic overactivity leads to the excessive release of glutamate that activates postsynaptic cell membrane receptors, which upon activation open their associated ion channel pore to produce ion influx. To date, although molecular basis of glutamate toxicity remain uncertain, there is general agreement that N-methyl-d-aspartate (NMDA) subtype of ionotropic glutamate receptors plays a key role in mediating at least some aspects of glutamate neurotoxicity. On this view, research has focused in the discovery of new compounds able to either reduce glutamate release or activation of postsynaptic NMDA receptors. Although NMDA receptor antagonists prevent excitotoxicity in cellular and animal models, these drugs have limited usefulness clinically. Side effects such as psychosis, nausea, vomiting, memory impairment, and neuronal cell death accompany complete NMDA receptor blockade, dramatizing the crucial role of the NMDA receptor in normal neuronal processes. Recently, however, well-tolerated compounds such as memantine has been shown to be able to block excitotoxic cell death in a clinically tolerated manner. Understanding the biochemical properties of the multitude of NMDA receptor subtypes offers the possibility of developing more effective and clinically useful drugs. The increasing knowledge of the structure and function of this postsynaptic NMDA complex may improve the identification of specific molecular targets whose pharmacological or genetic manipulation might lead to innovative therapies for brain disorders.
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PMID:New targets for pharmacological intervention in the glutamatergic synapse. 1683 14

Anti-NMDA receptor (NMDAR) encephalitis, formally recognized in 2007, has been increasingly identified as a significant cause of autoimmune and paraneoplastic encephalitis. Approximately 80% of the patients are females. The characteristic syndrome evolves in several stages, with approximately 70% of the patients presenting with a prodromal phase of fever, malaise, headache, upper respiratory tract symptoms, nausea, vomiting and diarrhoea. Next, typically within two weeks, patients develop psychiatric symptoms including insomnia, delusions, hyperreligiosity, paranoia, hallucinations, apathy and depression. Catatonic symptoms, seizures, abnormal movements, autonomic instability, memory deficits may also develop during the course of the disease. Presence of antibodies against the GluN1 subunit of the NMDAR in the CSF and serum confirm the diagnosis of NMDAR encephalitis, which also should prompt a thorough search for an underlying tumor. Age, gender, and ethnicity may all play a role, as black females older than 18 years of age have an increased likelihood of an underlying tumor. Treatment is focused on tumor resection and first-line immunotherapy [corticosteroids, plasma exchange, and intravenous immunoglobulin]. In non-responders, second- line immunotherapy [rituximab or cyclophosphamide or combined] is required. More than 75% of the patients recover completely or have mild sequelae, while the remaining patients end up demonstrating persistent severe disability or death. There is a paucity of literature on the management of psychiatric symptoms in this population. Given the neuropsychiatric symptoms in the relatively early phase of the illness, approximately 77 % of the patients are first evaluated by a psychiatrist. Earlier recognition of this illness is of paramount importance as prompt diagnosis and treatment can potentially improve prognosis. We describe two patients diagnosed with NMDAR encephalitis presenting with two different psychiatric manifestations. The first patient presented with psychotic mania and catatonic symptoms, while the second suffered from depression with psychotic and catatonic features refractory to psychotropic medications. We review of the use of psychotropic medications and ECT to address insomnia, agitation, psychosis, mood dysregulation and catatonia in NMDAR encephalitis.
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PMID:Management of psychiatric symptoms in anti-NMDAR encephalitis: a case series, literature review and future directions. 2473 34

N-methyl-D-aspartate receptor (NMDA) encephalitis is a recently described autoimmune disease that typically presents with prodromal symptoms including upper respiratory tract infection, headache, fever, nausea, vomiting and diarrhea. Psychiatric symptoms follow within weeks, including anxiety, insomnia, mania, paranoia and grandiose delusions. The diagnosis is confirmed by the detection of NMDA antibodies in the serum or cerebrospinal fluid (CSF).1 Tumours, especially teratomas, are frequently associated with NMDA encephalitis; however, only 5% of male patients older than 18 years have been found to have an underlying tumour. Optic neuropathy associated with NMDA encephalitis is being increasingly recognised in the literature2-6 and was reviewed most recently by Mugavin et al.2 in 2017. In this report, we present a case of bilateral optic neuropathy in a young man diagnosed with NMDA receptor encephalitis.
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PMID:Optic Nerve Atrophy in N-methyl-D-aspartate (NMDA) Encephalitis. 3172 24