Masui. The Japanese journal of anesthesiology
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Pregabalin has been available in Japan since June 2010 for neuropathic pain. The adverse effects of pregabalin might be serious, and one must start at minimal doses and increase gradually to effective doses with enough explanation to patients. Pregabalin is a derivative of y-aminobutyric acid (GABA), but it has no effects on GABA receptors. ⋯ The effects of pregabalin is to bind alpha2delta-1 subunit and normalize the numbers of VGCCs at neuron surface and decreases neurotransmission, especially by excitatory amino acid. The descending facilitating serotonergic system from rostral ventromedial medulla may have effects on the occurrence and maintenance for the chronic pain. New drugs with less adverse effects may be developed.
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The treatment of chronic pain, whether of cancer or noncancer origin, frequently involves the use of opioids. Delay in GI transit and constipation are the most common and often disabling side effects of opioid analgesics. ⋯ This goal is currently addressed by the use of opioid receptor antagonists with limited absorption such as oral naloxone and by the development of peripheral opioid receptor antagonists such as methylnaltrexone and alvimopan. These drugs hold considerable promise in preventing constipation due to treatments with opioids, whereas the analgesic action of opioids remains unabated.
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Opioids are available for patients with chronic non-cancer pain. At the start of treatment, side effects such as nausea and vomiting may occur. As these symptoms appear at a dose lower than that at which analgesic actions are achieved, preventive strategies are important. ⋯ It is also effective to use opioid rotation or change the administration route from oral to continuous subcutaneous administration. However, concerning chronic, non-cancer pain, the opioid rotation regimen is limited to a combination of codeine preparations, morphine preparations, and fentanyl patches. For long-term administration, the continuous intravenous/subcutaneous injection of opioids is not indicated.