Current pain and headache reports
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Recent discoveries in opioid pharmacology help explain the enormous variability in clinical responses to these powerful analgesics. Although there is only one m opioid receptor gene, splice variants of that gene's expression result in a panoply of different functioning receptors. Other sources of variable response include polymorphisms in the m opioid receptor regulatory region, and pharmacokinetic differences because of cytochrome P-450 mono-oxygenase heterogeneity. ⋯ Among them are the N-methyl-D-aspartate receptor, protein kinase C gamma activity, nitric oxide synthase, and GM1 ganglioside content of the neuronal membrane. Clinical studies undercut the routine use of meperidine in most settings. Other studies have shown better ways to diminish opioid side effects.
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Curr Pain Headache Rep · Feb 2003
Review Comparative StudyAnticonvulsants for the treatment of neuropathic pain syndromes.
This article is an evidence-based summary of randomized clinical trials published in peer-reviewed journals regarding the efficacy of anticonvulsants for the treatment of neuropathic pain.
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Curr Pain Headache Rep · Feb 2003
Review Comparative StudyErgotamine and dihydroergotamine: a review.
The ergot alkaloids were the first specific antimigraine therapy available. However, with the advent of the triptans, their use in the treatment of migraine has declined and their role has become less clear. This review discusses the pharmacology, efficacy, and safety of the ergots. ⋯ Ergotamine is still widely used in some countries for the treatment of severe migraine attacks. It is generally regarded as a safe and useful drug if prescribed for infrequent use, in the correct dose, and in the absence of contraindications; however, safer and more effective options do exist in the triptans. In patients with status migrainous and patients with frequent headache recurrence, ergotamine is still probably useful.
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Curr Pain Headache Rep · Feb 2003
Review Comparative StudyThe role of anticonvulsants in preventive migraine therapy.
The mainstay of migraine treatment is pharmacotherapy. There have been numerous medications used to prevent migraine headaches, including b-blockers, calcium-channel blockers, anticonvulsants, and nonsteroidal anti-inflammatory drugs. ⋯ The mechanism of action of antiepileptics is not fully understood, but they all share a common role in enhancing gamma-aminobutyric acid-mediated inhibition. This article reviews the role of anticonvulsants in preventive migraine therapy.
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Curr Pain Headache Rep · Feb 2003
ReviewOpioid resistance in chronic daily headache: a synthesis of ideas from the bench and bedside.
Chronic daily headache is a complex pain disorder that encompasses many diagnostic and therapeutic challenges. Our understanding of the pathophysiologic processes of intermittent migraine has improved over the past decade, but the biologic basis of chronic daily headache remains obscure. ⋯ Current concepts of the pathophysiologic basis of chronic pain and associated neural plasticity may elucidate a biologic basis for the general inefficacy of opioids in the management of chronic daily headache. This article explores the models of pathophysiology for migraine and chronic daily headache, the concept of chronic daily headache as a neuropathic pain syndrome, neural plasticity in the context of neuropathic pain states, the physiologic basis for opioid tolerance and opioid-induced hyperalgesia, and how each of these conditions interact to provoke the general lack of opioid efficacy often observed in the management of chronic daily headache.