Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026837 (muscle rigidity)
 1,077 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Abrupt termination of the treatment of humans with benzodiazepines (BDZs) leads to a rapid onset of discontinuation syndrome characterized by anxiety, muscle spasms, and occasionally convulsions. For this reason, it is recommended in clinical practice to reduce the dose of the BDZs gradually at the end of treatment. Nevertheless, many clinicians report signs of dependence even during gradual reduction of doses (tapering) of the BDZs in a large proportion of patients. Thus, there is considerable interest in discovering means of weaning patients away from BDZs without the risk of discontinuation syndrome. In the present study, mice withdrawn from chronic treatment with alprazolam showed anxiety, muscle rigidity, and seizures between days 1 and 28 after termination of the treatment. Replacement of alprazolam with the beta-carboline abecarnil for 7 days prevented the occurrence of the signs of dependence. In contrast, substitution of the beta-carboline antagonist ethyl-5-isopropoxy-4-methyl-beta-carboline-3-carboxylate (ZK93426) for alprazolam worsened the discontinuation syndrome. Replacement therapy with abecarnil after long-term treatment with the BDZs offers a novel method for rapid tapering.
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PMID:Alprazolam dependence prevented by substituting with the beta-carboline abecarnil. 912 63

Five thoroughbred foals (4 fillies and 1 colt), all in good to excellent body condition, ranging in age from 4 days to 5 weeks at the time of onset of signs, were presented to 2 Kentucky equine hospitals from 1992 through 1996. All 5 foals presented with tachycardia, hyperhidrosis, diarrhea or a recent history of diarrhea, and muscle rigidity or stiff gait. Four of the 5 foals presented for recumbency, seizure-like activity with opisthotonos, or pronounced extensor muscle rigidity. All 5 foals were hypocalcemic. All foals either died or had euthanasia performed. None responded to oral calcium supplementation. The cause of the hypocalcemia was unknown. Different idiopathic hypocalcemia syndromes may exist in foals.
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PMID:Idiopathic hypocalcemia in foals. 947 Jan 61

The traditional view of opioids held that the individual opioid agonists shared the same mechanism of action, differing only in their potency and pharmacokinetic properties. However, recent advances in opioid receptor pharmacology have made this view obsolete. Distinguishing features of the synthetic opioid agonists are related, at least in part, to variation in affinity and intrinsic efficacy at multiple opioid receptors. Respiratory depression is the opioid adverse effect most feared by anaesthesiologists. Specific kappa-receptor agonists produce analgesia with little or no respiratory depression. There are a number of commercially available kappa-receptor partial agonist drugs, the so-called agonist-antagonist or nalorphine-like opioids, which appear to have a limited effect on breathing. Within the series of fentanyl analogues there are differences in behaviour towards particular opioid receptors and there is evidence for subtle differences in respiratory depressant effects. Pethidine (meperidine) causes histamine release and myocardial depression, while the fentanyl analogues do not. Pethidine has atropine-like effects on heart rate, while fentanyl analogues reduce heart rate by a vagomimetic action. Severe bradycardia or even asystole is possible with fentanyl analogues, especially in conjunction with the vagal stimulating effects of laryngoscopy. Fentanyl analogues often produce minor reductions in blood pressure, and occasionally severe hypotension by centrally mediated reduction in systemic vascular resistance. Muscle rigidity and myoclonic movement occurs frequently during induction of anaesthesia with larger doses of opioids. Fentanyl and alfentanil have been reported to produce localised temporal lobe electrical seizure activity in patients with complex partial epilepsy. There are probably fewer biliary effects with agonist-antagonist opioids than the agonist opioids. The mechanism of adverse effects after spinal administration is distinctly different for morphine, which is very water soluble, compared with more lipid-soluble opioids. The systemic absorption of morphine after intrathecal or epidural administration is very slow, resulting in long duration of analgesia and low plasma concentrations, while lipid-soluble opioids are rapidly absorbed into the circulation and redistributed to the brain. The serotonin syndrome may result from coadministration of pethidine, dextromethorphan, pentazocine or tramadol with monoamine oxidase inhibitors (MAOIs) or selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors (SSRIs). There are clinically important interactions between opioids and hypnosedatives, resulting in synergistic effects on sedation, breathing and blood pressure.
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PMID:Adverse effects of opioid agonists and agonist-antagonists in anaesthesia. 974 65

The most venomous scorpion species are Buthotus tamulus of India, the Leiurus quinquestriatus and Androctonus crassicauda of North Africa and the Middle East, the Tityus serrulatus of Brazil, and the Centruroides suffussus of Mexico. The severity of scorpion envenomation varies with the scorpion's species, age, and size, and is much greater in children. Systemic intoxication reflects the overstimulation of the CNS, the sympathetic and parasympathetic nervous system. Severity ranges from local pain and paresthesia to fatal cardiotoxicity and encephalopathy. Symptoms include: agitation, tachycardia, vomiting, abdominal pain, salivation, diaphoresis, dehydration, muscle rigidity and twitching, tremor, seizures, coma, pupillary changes, hyperthermia, tachyarrythmias and occasionally bradyarrhythmias, hypertension, and less often hypotension, cardiac failure, and priapism in males. Laboratory abnormalities include: hyperglycemia, leucocytosis, transient elevation of cardiac and pancreatic enzymes, ischemic changes in the ECG, and evidence of cardiac dysfunction on echocardiography. The principles of management are: observation, cardiac monitoring, supportive treatment with intravenous fluids and electrolytes, and a meticulous use of cardiovascular agents: vasodilators, adrenergic antagonists, or calcium channel blockers in the hypertensive phase; and inotropic agents in the event of hypotension. Antiarrhythmics such as lidocaine, may be required. There is increasing evidence for the efficacy of specific antivenom. The advance in supportive care and antivenom efficacy has markedly improved the outcome of patients with scorpion envenomation.
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PMID:Clinical manifestations and management of scorpion envenomation. 1044 63

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by high instability and extension of CAG sequences within the coding region of IT15 gene. It affects both sexes and age at onset of the disease may be different but usually occurs in midlife. The term Juvenile Huntington's disease is generally applied to 10% of the cases with onset before 20. We present clinical features and results of DNA analysis in 16 patients from 14 families aged 9 to 36. The age of onset was between 5 to 20 years; duration of the disease was from 2 to 16 years. In 10 cases the mutated gene was transmitted by the affected father; only in two cases by the mother. In all cases anticipation manifested by earlier onset of the disease in subsequent generations and expansion of CAG repeats was documented. The number of CAG repeats was between 50 and 92 (mean 67.3). Progressive mental deterioration, declining school performance, hyperactivity and emotional disturbances were the first symptoms of juvenile HD. Neuropsychological assessment showed mean IQ in Wechsler test 59.6 and Mini-Mental State Examination scores 22.8. Rigidity and bradykinesia were predominant features in the cases with juvenile onset, the remaining ones developed choreatic movements. Three persons had epileptic seizures; two (both females) revealed behaviour and psychiatric disturbances. Amplitudes of somatosensory evoked potentials, visual evoked potentials and brainstem auditory evoked potentials were markedly reduced. MRI of the brain showed atrophy of heads of the caudate nuclei, putamen and globus pallidus.
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PMID:[Clinical and genetic study of juvenile form of Huntington's disease]. 1204 2

During the recent decade an increasing number of inquiries concerning cases of overdoses exhibiting typical signs of the serotonin syndrome have been recorded at the Swedish Poisons Information Centre. Four of these cases are presented together with a review of the literature. All patients had overdosed moclobemide and in one case this was the only drug taken. The other patients had ingested moclobemide together with citalopram (2 cases) and clomipramine (1 case). Moreover, other serotoninergic pharmaceuticals as sertraline and sumatriptan were simultaneously ingested in one case and buspirone in another. Three of the cases had hyperthermia, > 40 degrees C and the same number showed pronounced muscle rigidity, coma and mydriasis. Other severe signs and symptoms upon admission included positive Babinski and trismus in two cases each and seizures in one. All patients received mechanical ventilation. Two were treated with dantrolene sodium and one of them was given cyproheptadine as well. One patient received cyproheptadine treatment alone and another prolonged muscle relaxation. Three patients had a typical short clinical course, whereas one patient developed rhabdomyolysis, DIC and arrhythmias. All patients fully recovered.
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PMID:[Serotonin syndrome. Several cases of this often overlooked diagnosis]. 1208 84

A 59-year-old man, who was diagnosed as having Parkinson's disease and depression seven years ago and was on oral antiparkinsonian agents, antianxiety agents, and antidepressants, developed a high fever, disturbed consciousness, and marked muscle rigidity after discontinuation of etizolam and amitriptyline. He was admitted to a nearby hospital. Hypothyroidism had been noted two months before admission. Marked muscle rigidity and increased serum CK were observed. Since discontinuation of benzodiazepine has been known to rarely trigger a neuroleptic malignant syndrome (NMS), he was diagnosed as having NMS. After receiving dantrolene and bromocriptine, these symptoms temporarily improved but he again developed consciousness disturbance, and convulsive seizures associated with an elevated serum CK. He was transferred to our hospital. On admission, the CK level was normal at 168 IU/l, while free T4 was 0.6 ng/dl (normal range, 0.9-2.3) and TSH was 108.7 mU/ml (normal range, 0.2-4.2) in serum, indicating the presence of primary hypothyroidism. As an increase in thyroid hormone dosage improved the thyroid function to normal level, his disturbed consciousness and muscle rigidity gradually improved. Convulsive seizure and recurrence of NMS in a short interval are unusual in neuroleptic malignant syndrome. In this patient, hypothyroidism may have contributed to the development of malignant syndrome through metabolic changes of the central dopaminergic system, and discontinuation of etizolam, a kind of benzodiazepine, may have triggered NMS, since there has not been reported that discontinuation of antidepressants including amitriptyline triggers NMS.
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PMID:[A patient with Parkinson's disease complicated by hypothyroidism who developed malignant syndrome after discontinuation of etizolam]. 1242 63

During the recent decade an increasing number of inquiries concerning cases of overdoses exhibiting typical signs of the serotonin syndrome have been recorded at the Swedish Poisons Information Centre. Four of these cases are presented together with a review of the literature. All patients had overdosed moclobemide and in one case this was the only drug taken. The other patients had ingested moclobemide together with citalopram (2 cases) and clomipramine (1 case). Moreover, other serotoninergic pharmaceuticals as sertraline and sumatriptan were simultaneously ingested in one case and buspirone in another. Three of the cases had hyperthermia, > 40 degrees C and the same number showed pronounced muscle rigidity, coma and mydriasis. Other severe signs and symptoms upon admission included positive Babinski and trismus in two cases each and seizures in one. All patients received mechanical ventilation. Two were treated with dantrolene sodium and one of them was given cyproheptadine as well. One patient received cyproheptadine treatment alone and another prolonged muscle relaxation. Three patients had a typical short clinical course, whereas one patient developed rhabdomyolysis, DIC and arrhythmias. All patients fully recovered.
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PMID:[Serotonin syndrome--several cases of this often overlooked diagnosis]. 1255 8

Fyn-mediated tyrosine phosphorylation of N-methyl-D-aspartate (NMDA) receptor subunits has been implicated in various brain functions, including ethanol tolerance, learning, and seizure susceptibility. In this study, we explored the role of Fyn in haloperidol-induced catalepsy, an animal model of the extrapyramidal side effects of antipsychotics. Haloperidol induced catalepsy and muscle rigidity in the control mice, but these responses were significantly reduced in Fyn-deficient mice. Expression of the striatal dopamine D(2) receptor, the main site of haloperidol action, did not differ between the two genotypes. Fyn activation and enhanced tyrosine phosphorylation of the NMDA receptor NR2B subunit, as measured by Western blotting, were induced after haloperidol injection of the control mice, but both responses were significantly reduced in Fyn-deficient mice. Dopamine D(2) receptor blockade was shown to increase both NR2B phosphorylation and the NMDA-induced calcium responses in control cultured striatal neurons but not in Fyn-deficient neurons. Based on these findings, we proposed a new molecular mechanism underlying haloperidol-induced catalepsy, in which the dopamine D(2) receptor antagonist induces striatal Fyn activation and the subsequent tyrosine phosphorylation of NR2B alters striatal neuronal activity, thereby inducing the behavioral changes that are manifested as a cataleptic response.
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PMID:Fyn is required for haloperidol-induced catalepsy in mice. 1640 46

This paper reviews the main neurological complications of psychiatric drugs, in particular antipsychotics and antidepressants. Extrapyramidal syndromes include acute dystonia, parkinsonism, akathisia, tardive dyskinesia and tardive dystonia. Extrapyramidal symptoms (EPS) are less frequent with atypical than with conventional antipsychotics but remain common in clinical practice partly due to lack of screening by health professionals. Neuroleptic malignant syndrome (NMS) consists of severe muscle rigidity, pyrexia, change in conscious level and autonomic disturbance but partial forms also occur. NMS is particularly associated with the initiation and rapid increase in dose of high-potency antipsychotics but it has been reported with all the atypical antipsychotics and rarely with other drugs including antidepressants. Serotonin toxicity comprises altered mental state (agitation, excitement, confusion), neuromuscular hyperactivity (tremor, clonus, myoclonus, hyper-reflexia) and autonomic hyperactivity and occurs on a spectrum. Severe cases, termed serotonin syndrome, usually follow the co-prescription of drugs that increase serotonergic transmission by different pathways, for example a monoamine oxidase inhibitor (MAOI) and a selective serotonin reuptake inhibitor (SSRI). Most antipsychotics and antidepressants lower the seizure threshold and can cause seizures; the risk is greater with clozapine than with other atypical antipsychotics and greater with tricyclic antidepressants (TCAs) than with SSRIs. In randomised controlled trials in elderly patients with dementia atypical antipsychotics are associated with a higher risk of stroke and death than placebo. Cohort studies suggest that conventional drugs carry at least the same risk. Cessation of treatment with antipsychotics and antidepressants can lead to a wide range of discontinuation symptoms which include movement disorders and other neurological symptoms. Clinicians need to be familiar with strategies to reduce the risk of these adverse events and to manage them when they arise. Their occurrence needs to be balanced against the benefits of psychiatric drugs in terms of efficacy and improved quality of life in a range of disorders.
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PMID:Neurological complications of psychiatric drugs: clinical features and management. 1809 17


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