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

This case report describes a patient affected by a neuropathic pain syndrome, which was secondary to a renal cell carcinoma metastatic to the spine, and complicated by incidental components and somatization. Due to a rapid development of tolerance and toxicity from hydromorphone, a rotation to methadone was made, with a decrease of the morphine equivalent daily dose (MEDD) from 1050 to 36. After 4 mos of good pain relief, a switch over back to hydromorphone was necessary due to worsening pain, associated with myoclonus and sedation secondary to methadone; the MEDD this time escalated from 480 to 4950. The use of hydromorphone was complicated by the onset of intractable nausea and sedation. After 2 wks, the patient was rotated again to methadone, with a decrease of the MEDD to 24. He achieved good pain control and was free of opioid toxicity. Our findings illustrate a role of methadone in the management of cancer pain associated with poor prognostic indicators, the development of tolerance towards its effects, and the regaining of sensitivity to methadone, by temporary rotation to another opioid. Possible mechanism for opioid tolerance and its reversal are discussed.
Pain 1996 Sep
PMID:Individualized use of methadone and opioid rotation in the comprehensive management of cancer pain associated with poor prognostic indicators. 889 38

A 62-year-old man receiving subcutaneous fentanyl for the management of cancer pain developed generalized central excitation after an overdose of 5000 micrograms of fentanyl. The patient developed acute confusion, restlessness, generalized myoclonus, visual hallucinations, and hyperalgesia and tremors upon tactile stimulation of the arms or legs. These symptoms rapidly disappeared after the administration of 0.2 mg of naloxone. Within an hour the symptoms reappeared and once again, responded immediately after a second injection of 0.2 mg of naloxone. Our findings suggest that fentanyl overdose can occasionally present with general central irritability that responds to naloxone.
Pain 1997 Jan
PMID:Acute neuropsychiatric findings in a patient receiving fentanyl for cancer pain. 906 31

Morphine is a potent opioid analgesic widely used for the treatment of acute pain and for long-term treatment of severe pain. Morphine is a member of the morphinan-framed alkaloids, which are present in the poppy plant. The drug is soluble in water, but its solubility in lipids is poor. In man, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) are the major metabolites of morphine. The metabolism of morphine occurs not only in the liver, but may also take place in the brain and the kidneys. The glucuronides are mainly eliminated via bile and urine. Glucuronides as a rule are considered as highly polar metabolites unable to cross the blood-brain barrier. Although morphine glucuronidation has been demonstrated in human brain tissue, the capacity is very low compared to that of the liver, indicating that the M3G and M6G concentrations observed in the cerebrospinal fluid (CSF) after systemic administration reflect hepatic metabolism of morphine and that the morphine glucuronides, despite their high polarity, can penetrate into the brain. Like morphine, M6G has been shown to be relatively more selective for mu-receptors than for delta- and kappa-receptors while M3G does not appear to compete for opioid receptor binding. The analgesic properties of M6G were recognised in the early 1970s and more recent work suggests that M6G might significantly contribute to the opioid analgesia after administration of morphine. The analgesic potency of M6G after intracerebroventricular (ICV) or intrathecal (IT) administration in rats is from 45-800 timer greater than that of morphine, depending on the animal species and the experimental antinociceptive test used. Furthermore, the development of a sensitive high-performance liquid chromatography (HPLC) assay for the quantitative determination of morphine, M6G and M3G has revealed that M6G and M3G were present in abundance after chronic oral morphine administration and that the area under the plasma concentration-time curve exceeded that of morphine. M3G has been found to antagonise morphine and M6G induced analgesia and ventilatory depression in the rat, which has led to the hypothesis that M3G may influence the development of morphine tolerance. M3G exhibits no analgesic effect after ICV or IT administration. Some studies do, however, indicate that M3G may cause non-opioid mediated hyperalgesia/allodynia and convulsions after IT administration in rats. These observations led to the hypothesis that M3G might be responsible for side-effects, hyperalgesia/allodynia and myoclonus seen after high-dose morphine treatment.
 ...
PMID:Morphine metabolites. 906 Oct 94

Pain occurs in more than 80% of cancer patients before death. Because of the increase in the frequency of cancer deaths worldwide, it is imperative to address cancer pain as a public health problem. Until recently, educational efforts were focused on treatment issues rather than adequate assessment. The approach to pain intensity as a multidimensional construct has helped in focusing treatments and identifying prognostic factors. Valid tools have been developed that allow multidisciplinary assessment of these prognostic factors and their complex interrelationship with the analgesic response. As a result of increased opioid exposure, patients are currently developing newer toxicities, mostly central excitability including delirium, myoclonus, grand mal seizures, and hyperalgesia. The observation that more than 80% of patients will require alternate routes for opioid delivery before death led to the development of a number of novel and effective alternate routes for delivery. Finally, in recent years it has become evident that some specific pain syndromes need to be addressed using specific assessment and management techniques. Incidental pain, somatization, neuropathic pain, and cancer pain in patients with alcoholism and drug addiction are some of these syndromes.
 ...
PMID:Cancer pain management. 906 Oct 98

A case of severe opioid toxicity is described in a 52-year-old cancer patient. The patient presented with classical clinical features of central hyperexcitability associated with opioid toxicity: delirium, myoclonus, hallucinations, hyperalgesia, and a possible seizure. This patient had a background of severe psychosocial distress and somatization in addition to a history of benzodiazepine dependence and alcohol abuse. The occurrence of opioid toxicity in this patient highlights the risks of a unidimensional approach to cancer pain, which ignores the non-organic components of pain, such as psychosocial distress, which will not respond to escalating doses of opioid medication.
J Pain Symptom Manage 1997 Jun
PMID:Severe opioid toxicity and somatization of psychosocial distress in a cancer patient with a background of chemical dependence. 920 57

While occasional myoclonic jerks are prevalent in cancer patients receiving opioids, severe myoclonic jerks and seizures due to opioids are uncommon. In this retrospective case series, we describe five cancer patients with refractory cancer pain and severe neuroexcitatory toxicity associated with extremely high-dose opioid therapy to characterize better the syndrome, its treatment, and its outcome. Two patients died following seizures, but three patients recovered following prompt treatment with parenteral midazolam infusions and rotation to alternative opioids. Possible mechanisms and treatment options for this potentially lethal clinical syndrome are reviewed. The authors conclude that severe multifocal myoclonus and seizures associated with extremely high-dose opioid therapy are life-threatening, and respond to parenteral midazolam infusion, rotation to alternative opioids, and aggressive supportive care.
J Pain Symptom Manage 1997 Jul
PMID:Strychnine-like multifocal myoclonus and seizures in extremely high-dose opioid administration: treatment strategies. 956 11

Pain affects most patients with malignant disease, and the prevalence of severe pain increases in the advanced stages of the condition. One in 5 patients with cancer has uncontrolled pain, even after 10 years of the use of the World Health Organization programme for cancer pain control and its 'three-step ladder' for the rational use of analgesics including morphine. Morphine has long been the 'gold standard' for the treatment of severe cancer pain. However, its side-effects, particularly sedation, cognitive impairment and myoclonus at high doses, have provoked the use of 'opioid rotation' to alternatives such as methadone and hydromorphone. The new 72-h transdermal patch for fentanyl also offers advantages of reduced side-effects and increased convenience over oral morphine. Intravenous strontium-89 and bisphosphonate therapy are effective for both short- and long-term control of metastatic bone pain. The spinal N-methyl-D-aspartate (NMDA) receptor is important in modulating the plasticity of the central nervous system and in aggravating chronic pain through the phenomenon of 'wind-up'. The NMDA antagonist ketamine, an anaesthetic, can be used at low doses for the management of refractory and neuropathic pains. Among adjuvant drugs, ketorolac has emerged as a potent non-steroidal anti-inflammatory drug. Palliative care is gaining acceptance as a new discipline in healthcare. Its strategic role is being reviewed as an adjunct to cancer therapy at all stages and its use is no longer confined to the terminal phase of disease after curative treatment has failed. Pain control and other aspects of symptom control are, therefore, viewed as an integral part of cancer management.
 ...
PMID:New approaches to pain control in patients with cancer. 940 34

Posthypoxic myoclonus (Lance-Adams' syndrome) is a rare complication of cardiorespiratory arrest. It has a better prognosis than other movement disorders secondary to brain ischaemia. We report a case of posthypoxic myoclonus in a 66-year-old woman after acute myocardial infarction and cardiopulmonary arrest. She had action and intention myoclonus, and these movements were also initiated by acoustic and pain stimuli. The origin of the myoclonus was probably subcortical, and it improved with clonazepam 2 mg t.i.d. We emphasize that early diagnosis is necessary in intensive care units in order to avoid misinterpretation of this syndrome and to start appropriate treatment.
 ...
PMID:Posthypoxic myoclonus in intensive care. 942 52

Myoclonus occasionally occurs in the perioperative setting and in patients on chronic opioid therapy. It appears to be dose-related in a unpredictable manner. Different mechanisms have been proposed to explain the occurrence of a series of neuromuscular disturbances probably sharing final common pathways. A neuroexcitatory opioid metabolite accumulation has been proposed to have a relevant role in determining myoclonus in patients treated with chronic opioid therapy for cancer pain, especially in the presence of renal impairment. The neurological status, previous oncologic treatment and concomitant therapy with neuroleptic drugs, the metabolic and hydration status should also have been considered. Adjuvant drugs, such as benzodiazepines or dantrolene may avoid the reduction of the opioid dose while maintaining an acceptable analgesia. Current practice suggests a change in opioid when pain control is not obtained at opioid doses resulting in unacceptable adverse effects, including myoclonus and hyperalgesia. A change in the type of opioid may be useful in patients who develop severe central adverse effects, even if these patients appear to have normal renal function or hydration status.
Pain 1998 Jan
PMID:Pathophysiology and treatment of opioid-related myoclonus in cancer patients. 951 54

We report here a boy suffering from muscle cramps in the right upper extremity. At 32 days of age, he developed purulent meningitis followed by paresis of the right upper extremity. From infancy he had intermittent episodes myoclonus-like involving the right hand. Since he also had true epileptic seizures with loss of consciousness, ocular deviation, and vomiting at 6 and 8 years of age, he was treated with anti-epileptic drugs as therapy for focal motor seizures. At 6 years of age, these episodes increased in frequency. The cramps spread from the right hand to involve the entire upper extremity with pain. At the age of 10, he was referred to Hirosaki University Hospital and was admitted. Using closed circuit television with continuous EEG and EMG monitoring we observed during his episodes repeated EMG abnormalities consisting of continuous discharges of polyphasic motor unit potentials, but no epileptic EEG discharges. We diagnosed these episodes as muscle cramp. His muscle cramps were controlled by medication with muscle relaxants and Chinese medicines. This case illustrates that the differential diagnosis between muscle cramps and epileptic seizures is important for proper treatment.
 ...
PMID:[Case report of muscle cramp versus focal epilepsy]. 1048 69


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>