Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Photosensitivity was acquired as a result of kindling in the lateral geniculate body (GL), and the GL-kindled cat pretreated with DL-allylglycine showed a stable level of photosensitivity. To test the usefulness as a model for the evaluation of anticonvulsant drugs, the effects of phenobarbital (PB) and phenytoin (PHT) on photosensitivity were studied in the GL-kindled cat under DL-allylglycine. PB (5 and 10 mg/kg intravenously, i.v.) completely suppressed photically induced seizures in most subjects at plasma concentrations of 7-16 micrograms/ml, and this anticonvulsant action persisted for at least 4 h after the injection. PHT (15 mg/kg, i.v.) at plasma concentrations of 9-15 micrograms/ml produced toxic signs, e.g., pupil dilatation, hypersalivation, and tachypnea. At this dose, PHT was inactive against photically induced myoclonus but prevented the elicitation of a generalized tonic-clonic convulsion. From these results showing that the effects of anticonvulsant drugs on photically induced seizures can be assessed in relation to plasma concentration and acute neurologic toxicity, we suggest that the GL-kindled cat is a potentially useful animal model of epilepsy for testing the efficacy of anticonvulsant drugs.
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PMID:A new experimental model for drug studies: effects of phenobarbital and phenytoin on photosensitivity in the lateral geniculate-kindled cat. 369 16

The typical symptoms and signs of neuroleptic malignant syndrome (NMS) consist of fever muscle rigidity (stiffness, myoclonus, rod-like), alterations of consciousness (confusion, agitation, aggression, or catatonia), autonomic nervous system disturbances (i.e., hypertension, tachycardia, tachypnea, profuse sweating, and urine incontinence), abnormal blood tests such as low serum electrolytes, elevated serum creatinine phosphokinase (CPK) level, and leukocytosis. Muscle rigidity is often associated with myonecrosis, myoglobinuria, and elevated serum CPK. The mortality among NMS cases is in the 10 to 70% range depending on the severity of the symptoms and time of therapeutic approach. Mandatory therapy should include removal of causative agents, correction of body fluid and electrolytes, administration of benzodiazepine, clonazepam and bromocriptine (dopamine agonist), proved life-saving medications. The authors reported herein six cases with unusual clinical features of NMS. Four of them had been on antipsychotic for a year before becoming anorexic, dehydrated, agitated, and violent with paranoid delusion. One instance with underlying delirium tremens developed NMS after receiving haloperidol (30 mg IV) in addition to diazepam (200 mg IV) within 24 hours. Another patient was found to suffer from severe NMS after receiving bupropion (Dopamine inhibitor antidepressant) 300 mg/day. All patients displayed cardinal signs and symptoms of NMS in addition to dehydration and pallor. They were treated in the psychiatric ward and recovered rapidly from NMS after receiving clonazepam and bromocriptine and removal of the offending agents.
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PMID:Neuroleptic malignant syndrome: a review and report of six cases. 1721 72

Sleep-disordered breathing and sleep-related motor phenomena are part of the clinical spectrum of multiple system atrophy (MSA). Stridor has been attributed to denervation of laryngeal muscles or instead to dystonic vocal cord motion. We studied 3 patients with nocturnal stridor in the setting of MSA. All patients underwent nocturnal videopolysomnography (VPSG) with breathing and heart rate, O(2) saturation and intra-esophageal pressure recordings, and simultaneous EMG recordings of the posterior cricoarytenoid, cricothyroid, and thyroarytenoid muscles and continuous vocal cord motion evaluation by means of fiberoptic laryngoscopy. VPSG/EMG and fiberoptic laryngoscopy documented normal vocal cord motion without denervation during wake and stridor only during sleep when hyperactivation of vocal cords adductors appeared in the absence of significant O(2) desaturation. All patients had tachycardia and tachypnea and paradoxical breathing during sleep, erratic intercostalis and diaphragmatic EMG activity and Rem sleep behavior disorder. One of the patients had restless legs syndrome with periodic limb movement during sleep and excessive fragmentary hypnic myoclonus. In conclusion, our patients with MSA had nocturnal stridor due to sleep-related laryngeal dystonia. Stridor was associated with other abnormal sleep-related respiratory and motor disorders, suggesting an impairment of homeostatic brainstem integration in MSA.
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PMID:Sleep-related stridor due to dystonic vocal cord motion and neurogenic tachypnea/tachycardia in multiple system atrophy. 1726 93

Serotonin syndrome is a potentially life-threatening adverse drug reaction caused by excessive serotonergic agonism in central and peripheral nervous system serotonergic receptors (Boyer EW, Shannon M. The serotonin syndrome. N Engl J Med 2005;352:1112-1120). Symptoms are characterized by a triad of neuron-excitatory features, which include (a) neuromuscular hyperactivity -- tremor, clonus, myoclonus, hyperreflexia and, in advanced stages, pyramidal rigidity; (b) autonomic hyperactivity -- diaphoresis, fever, tachycardia and tachypnea; (c) altered mental status -- agitation, excitement and, in advanced stages, confusion (Gillman PK. Monoamine oxidase inhibitors, opioid analgesics and serotonin toxicity. Br J Anaesth 2005;95:434-441). It arises when pharmacological agents increase serotonin neurotransmission at postsynaptic 5-hydroxytryptamine 1A and 5-hydroxytryptamine 2A receptors through increased serotonin synthesis, decreased serotonin metabolism, increased serotonin release, inhibition of serotonin reuptake or direct agonism of the serotonin receptors (Houlihan D. Serotonin syndrome resulting from coadministration of tramodol, venlafaxine, and mirtazapine. Ann Pharmacother 2004;38:411-413). The etiology is often the result of therapeutic drug use, intentional overdosing of serotonergic agents or complex interactions between drugs that directly or indirectly modulate the serotonin system (Boyer EW, Shannon M. The serotonin syndrome. N Engl J Med 2005;352:1112-1120). Due to the increasing availability of agents with serotonergic activity, physicians need to more aware of serotonin syndrome. The following case highlights the complex nature in which serotonin syndrome can arise, as well as the proper recognition and treatment of a potentially life-threatening yet easily avoidable condition.
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PMID:Serotonin syndrome: a complex but easily avoidable condition. 1843 63

The serotonin syndrome is a toxic state largely attributable to changes in sensitivity of serotonin receptor system in the brainstem and spinal cord resulting from increased serotonergic activity in central neurologic system, due to use of serotonergic agents either in overdose or in combination. Serotonin syndrome may present with neuromuscular (clonus, myoclonus, tremor, hyperreflexia) and autonomic (fever, mydriasis, tachycardia, tachypnea) symptoms and mental status changes (confusion, agitation) and may result in death in severe cases. The risk for the development of serotonin syndrome is increased with the combined use of agents from different groups such as selective serotonin reuptake inhibitors (SSRIs) and monoamine oxidase inhibitors (MAOIs). The growing use of SSRIs for depression and the introduction of pharmacological agents newly developed for the treatment of various medical disorders increases the risk of drug-drug interactions and toxic states like serotonin syndrome. In the presented case clinical presentation and outcome of the serotonin syndrome which has developed as a consequence of concomitant linezolid use in a young patient who was already on an SSRI antidepressant is discussed. Linezolid is an oxazolidinone antibiotic which has MAOI-like properties. This case is presented to inform psychiatrists especially working in consultation-liaison settings about the risk of drug-drug interactions and possible prevention of these.
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PMID:[Serotonin syndrome associated with linezolid use: a case report]. 2001 32

The serotonin toxicity (ST) is a potentially life-threatening adverse drug reaction results from therapeutic drug use, intentional self-poisoning, or inadvertent interactions between drugs. ST can be caused by a single or a combination of drugs with serotonergic activity due to excessive serotonergic agonism on central nervous system and peripheral serotonergic receptors (monoamine oxidase inhibitors, tricyclic antidepressants, SSRIs, opiate analgesics, over-the-counter cough medicines, antibiotics, weight-reduction agents, antiemetics, antimigraine agents, drugs of abuse, H2-antagonist and herbal products). The serotonin toxicity is often described as a clinical triad of mental-status changes (agitation and excitement with confusion), autonomic hyperactivity (diaphoresis, fever, tachycardia, and tachypnea), neuromuscular abnormalities (tremor, clonus, myoclonus, and hyperreflexia) and, in the advanced stage, spasticity; not all of these findings are consistently present. In this article, we describe two cases of ST due to interaction between Citalopram and two CYP2D6 inhibitors: Cimetidine and Topiramate and their clinical resolution after treatment discontinuation.
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PMID:Serotonin toxicity: a short review of the literature and two case reports involving citalopram. 2149 Oct 99

Serotonin syndrome is an unexpected fatal adverse event related to serotonergic medication. This case report is the first report describing the possible treatment effect of famotidine on serotonin syndrome. Furthermore, this is the first case report of serotonin syndrome induced by meperidine alone in a patient with no previous history suggesting a susceptibility to serotonin syndrome. A 70-year-old male with no recent history of serotonergic drug use presented with severe serotonin syndrome following ureteroscopy, possibly due to postoperative meperidine administration. The patient's symptoms included hypertension, tachycardia, tachypnea, hyperthermia, myoclonus, diaphoresis, retching, nausea, agitation, and semicoma mentality with no pupillary light reflex. Symptoms began to subside immediately after the administration of intravenous famotidine for prevention of aspiration pneumonia, with mental and neurological symptoms showing improvement initially, followed by autonomic symptoms. This case report suggests that the histamine type 2 receptor antagonist famotidine may be an effective emergency treatment for serotonin syndrome.
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PMID:Famotidine-induced reversal of meperidine-related serotonin syndrome: a case report. 2836 96