Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alpha(2) agonists have been in clinical use for decades, primarily in the treatment of hypertension. In recent years, alpha(2) agonists have found wider application, particularly in the fields of anesthesia and pain management. It has been noted that these agents can enhance analgesia provided by traditional analgesics, such as opiates, and may result in opiate-sparing effects. This has important implications for the management of acute postoperative pain and chronic pain states, including disorders involving spasticity or myofascial pain, neuropathic pain, and chronic daily headaches. The clinical utility of these agents is ever expanding, as they are gaining broader use in neuraxial analgesia, and new applications are continuously under investigation. The alpha(2) agonists that are currently employed in anesthesia and pain management include clonidine, tizanidine, and dexmedetomidine. Moxonidine and radolmidine, which are not currently in clinical use in humans, may offer favorable side-effect profiles when compared with traditional alpha(2) agonists, and may thereby allow for more widespread pain management applications.
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PMID:Alpha(2) receptors and agonists in pain management. 1701 39

The family of alpha(2)-adrenergic receptors (alpha(2)-ARs) comprises three subtypes which are each endowed with specific functions. alpha(2)-agonists and alpha(2)-antagonists are part of the clinician armamentarium since several decades; however, none of the compounds so far available is subtype selective. For long, clonidine and yohimbine have been used for the treatment of hypertension and impotence respectively, but both have been superseded by newer drugs. This review attempts, by a comprehensive analysis of the literature, to cover the present clinical use and the potential therapeutic interest of alpha(2)-agonists or antagonists. From the clinical data, it is concluded that, with the exception of a few particular situations, alpha(2)-agonists are only of limited utility as a monotherapy. By contrast, they offer several powerful advantages when used in adjunctive therapy. In perioperative settings, alpha(2)-agonists are extremely valuable adjuncts to anesthetics and analgesics for the induction of anxiolysis, maintenance of sedation, management of pain and prevention of shivering. In the ophthalmic clinic, they are used to lower intra-ocular pressure during laser surgery of the eye. As a daily medication, alpha(2)-agonists are also of interest for the treatment of glaucoma, muscle spasticity, opiate withdrawal, and behavior disorders. The alpha(2)-antagonists are useful antidotes for reversing the threatening effects of agonist overdose, but currently there are very few indications. New applications are under investigation, and new molecules with more refined subtype-selectivity may emerge, so the clinical utility of both alpha(2)-agonists and antagonists will undoubtedly expand in the future.
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PMID:Interest of alpha2-adrenergic agonists and antagonists in clinical practice: background, facts and perspectives. 1726 5

Spinal cord infarction is uncommon and usually presents with sudden onset of paralysis and sensory disturbances. A variety of causes are described, but rarely with multiple factors involved. We report a case of a 63-year-old man with a history of diabetes mellitus, hypertension, and osteoarthritis who presented with acute onset of chest pain, numbness, and weakness associated with episodic hypotension. He had incomplete tetraplegia and was areflexic without spasticity. Pain and temperature sensations were impaired below the C7 dermatome and absent below the T4 dermatome bilaterally. Proprioception and vibration sensations were diminished on the right below the C6 dermatome. Magnetic resonance imaging showed spinal cord infarction affecting C6-T3 segments, and severe cervical and lumbar spine degenerative changes. This case illustrates an unusual presenting symptom of spinal infarction, the need to identify multiple risk factors for spinal cord infarction, and the importance of optimal preventive therapy in patients at risk.
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PMID:Spinal cord infarction with multiple etiologic factors. 1735 58

Intrathecal baclofen (ITB) withdrawal is a well-recognized complication when drug delivery is disrupted for any reason. ITB withdrawal varies widely in its severity and poses the very real possibility of death if not promptly managed. Cases of withdrawal lasting greater than 1 or 2 weeks, however, are sparse. We report the case of an 11-year-old girl with spastic quadriplegic cerebral palsy who developed an infected pump and subsequent meningitis, prompting the removal of her pump and catheter. She subsequently developed a severe, prolonged baclofen withdrawal syndrome marked by increased spasticity, agitation, hypertension, and tachycardia that lasted nearly 2 months, requiring intensive care and continuous intravenous sedation with benzodiazepines and opiates. Her pump was eventually replaced on hospital day 56 and within 24 hours her symptoms dramatically improved. She was eventually weaned off sedating medications and returned to baseline functional status. Typical management of baclofen withdrawal is reviewed. To date, the literature has not discussed the potential role for opiates in managing baclofen withdrawal, yet a growing body of literature is examining the interplay between opiates and gamma-aminobutyric acid B pathways. A potential role for opiates in managing severe baclofen withdrawal is proposed.
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PMID:Prolonged, severe intrathecal baclofen withdrawal syndrome: a case report. 1796 89

In children with spasticity, deep tendon reflexes are hyperactive and even stimulation of normal dorsal rootlets can produce exaggerated full-strength, single-twitch responses in the muscles they innervate. This phenomenon is called the brisk hyperactive response (BHR). The aim of this study was to compare the efficacy of 2 volatile anesthetics, isoflurane and sevoflurane, for suppressing the confounding effect of BHR during selective dorsal rhizotomy (SDR) in children with spasticity. The subjects were 54 consecutive children of American Society of Anesthesiology physical status III who were scheduled for SDR. After tracheal intubation, each child was randomly assigned to Group I (isoflurane; n=27) or Group S (sevoflurane; n=27). There was no significant difference between the mean operation times in Groups I and S (200+/-40 vs. 220+/-35 minutes, respectively; p=0.0559). Thirteen patients in Group I (48.1%) and 5 in Group S (18.5%) exhibited BHR during stimulation of the dorsal rootlets (odds ratio 4.086; p=0.0418). Three of these 18 patients (2 in Group I and 1 in Group S) experienced hypertension and tachycardia simultaneously with BHR (odds ratio 4.086; p=1.0). The results suggest that sevoflurane is more effective at preventing BHR and might be a better choice for anesthetic management of children with spasticity undergoing SDR.
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PMID:Prevention of brisk hyperactive response during selective dorsal rhizotomy in children with spasticity: isoflurane versus sevoflurane maintenance anesthesia. 1910 94

Autonomic dysreflexia may occur following spinal cord injury above mid-thoracic level, commonly developing in the early posttraumatic period. Cardiovascular dysregulation is the most prominent feature, characterized by paroxysmal high blood pressure attacks, which are precipitated by distension of urinary bladder or bowels, skin wounds, or increased spastic muscle tone. Severe drops in blood pressure may occur in orthostatic conditions. Baclofen is effective for treating spasticity. While orally administered baclofen often fails to alleviate severe spasticity adequately, intrathecal baclofen (ITB) is more effective and thus is being used increasingly. A 61-year-old male sustained a cervical spinal cord injury, subsequently developing severe spastic tetraparesis, predominantly in the legs. Some 30 years later he experienced marked spasms of the muscles of the abdominal wall, leading to extreme fluctuations of blood pressure. After positive evaluation with ITB the patient underwent implantation of a pump-catheter-system for continuous ITB application. Abdominal wall spasms ceased entirely with a daily dose of 190 microg ITB, accompanied by a sustained normotensive blood pressure profile. However, spasms reoccurred after inadvertent reduction of ITB flow when increasing the pump's ITB concentration but subsided again when the optimal antispastic dose was reestablished. Baclofen per se has the potential of lowering blood pressure. In this patient, however, ITB treatment enabled permanent stabilization of insidious blood pressure fluctuations. It would appear that suppression of abdominal spasms prevented the triggering of dysautonomic crises. This case demonstrates that ITB administration may help to stabilize autonomic dysreflexia and orthostatic hypotension in patients with spinal cord lesions.
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PMID:Intrathecal baclofen for autonomic instability due to spinal cord injury. 1915 92

Intrathecal baclofen (ITB) is increasingly being used to reduce spasticity among children with cerebral palsy, dystonia, and spinal cord injuries. However, complications such as withdrawal, which is a potentially life-threatening condition, can occur. Intrathecal baclofen withdrawal should be differentiated with autonomic dysreflexia, malignant hyperthermia, neuroleptic malignant syndrome, and serotonin syndrome. We report a case of ITB withdrawal secondary to low residual volume in the pump reservoir and resembling serotonin syndrome in an adolescent with cerebral palsy. He presented with agitation, diaphoresis, increasing spasticity, rigidity, jitteriness, hyperreflexia, clonus, tachycardia, hypertension, and rhabdomyolysis. Treatment consisted of emergent refilling of the pump, intravenous diazepam, and oral cyproheptadine. We also emphasize the importance of prompt recognition of ITB withdrawal among high-risk patients.
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PMID:Intrathecal baclofen withdrawal resembling serotonin syndrome in an adolescent boy with cerebral palsy. 1924 Jun 73

Autonomic dysreflexia (AD) is not an uncommon clinical condition and it is usually detected in patients with complete spinal injuries at or above thoracic 6th vertebral level (T 6). This condition is reported to occur in 48- 60% of cases of spinal cord injury at or above the level of T6. But AD due to injury below T6 is rare. The basic mechanism is thought to be due to excessive, uncontrolled activation of sympathetic system. In the present case, we discuss a persistent AD in 55-yr-old tetraplegic patient with C5 American Spinal Injury Association (ASIA) grade A lesion due to a fall from 10 metre height. MRI examination showed C5 and C6 bi-facets fracture and dislocation with canal compromise. Wiring and fusion was performed but recurrent mucous plugging and aspiration pneumonia and urinary tract infection happened during the hospital stay. Three months later, he was re-admitted with multiple pressure sores, pneumonia, sepsis and high blood pressure. He was administered with nifedepine but the blood pressure kept fluctuating. The present study highlights how the precipitating factors like concomitant urinary tract infection, decubitus ulcers, spasticity triggered the AD attack. The knowledge of the AD and its proper diagnosis and management may be beneficial to all clinicians and the present article attempts to highlight such.
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PMID:An interesting case of autonomic dysreflexia. 1999 83

GABA(B) receptors belong to family III G protein-coupled receptors (GPCRs) and are widely distributed in the peripheral and central nervous systems. The GABA(B) receptor is one of the most important therapeutic targets in the treatment for spasticity. GABA(B) agonists, such as baclofen, are used as muscle relaxants clinically and are effective for the treatment of anxiety, depression, epilepsy, and cognitive disorders (Caddick & Hosford, 1996; Dichter, 1997; Enna & Bowery, 1997). In addition, GABA(B) receptors regulate neurotransmitter release and neuronal excitability in the brain regions involved in the autonomic nervous system. Recent studies have led to a better understanding of the role of GABA(B) in the regulation of the autonomic nervous system, especially in disease conditions such as hypertension. Here, we provide an overview of the recent progress, a discussion of disparate and contradictory findings, and a description of theories used to explain various cardiovascular effects of GABA(B) receptor drugs. Particular emphasis is placed on the role of GABA(B) receptors in the neural plasticity of brain regions related to the control of sympathetic outflow in cardiovascular disorders.
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PMID:Role of GABAB receptors in autonomic control of systemic blood pressure. 2065 86

Spasticity is a state of sustained pathological increase in the tension of a muscle. Treatment for spasticity has been revolutionized by the introduction of intrathecal baclofen (ITB) continuous infusion. ITB is associated with a 30% rate of complications mostly as a result of catheter problems that lead to acute ITB withdrawal. We describe a 10-year-old girl with spastic quadriplegia caused by cerebral palsy successfully treated with ITB who developed dystonic-dyskinetic status following acute ITB withdrawal because of a catheter kink resolved by external manipulation. The patient presented with a subacute onset of generalized malaise characterized by anorexia, difficulty in speaking and swallowing, insomnia, worsening of hypertonus with a left predominance, and late appearance of dystonic-dyskinetic movements. Soon after hospitalization the child had a generalized tonic-clonic seizure followed by unresponsiveness. One hour later she developed multiple muscle contractions with dystonic posturing and continuous chaotic movements. She also had pyrexia, tachycardia, and hypertension. A video/EEG recording showed the nonepileptic nature of the symptoms and revealed dystonic-dyskinetic status. We report the clinical features and the video recording of the status. The prompt recognition of this life-threatening complication is essential, as rapid treatment may reduce the increased risk of death. Misdiagnosis is possible, and video/EEG monitoring is useful to this end. Although differing among patients, all symptoms are related to overexcitability of the extrapyramidal and autonomic systems.
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PMID:Prolonged episode of dystonia and dyskinesia resembling status epilepticus following acute intrathecal baclofen withdrawal. 2160 4


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