Nonsteroid anti-inflammatory drugs (NSAIDs) are major drugs against inflammation and pain. They are well known inhibitors of cyclooxygenases (COXs). However, many studies indicate that they may also act on other targets. Acidosis is observed in inflammatory conditions such as chronic joint inflammation, in tumors and after ischemia, and greatly contributes to pain and hyperalgesia. Administration of NSAIDs reduces low-pH-induced pain. The acid sensitivity of nociceptors is associated with activation of H(+)-gated ion channels. Several of these, cloned recently, correspond to the acid-sensing ion channels (ASICs) and others to the vanilloid receptor family. This paper shows (1) that ASIC mRNAs are present in many small sensory neurons along with substance P and isolectin B4 and that, in case of inflammation, ASIC1a appears in some larger Abeta fibers, (2) that NSAIDs prevent the large increase of ASIC expression in sensory neurons induced by inflammation, and (3) that NSAIDs such as aspirin, diclofenac, and flurbiprofen directly inhibit ASIC currents on sensory neurons and when cloned ASICs are heterologously expressed. These results suggest that the combined capacity to block COXs and inhibit both inflammation-induced expression and activity of ASICs present in nociceptors is an important factor in the action of NSAIDs against pain.
Etodolac should be avoided by patients with a history of asthma attacks, hives , or other allergic reactions to aspirin or other NSAIDs. Rare but severe allergic reactions have been reported in such individuals. It also should be avoided by patients with peptic ulcer disease or poor kidney function , since this medication can worsen both conditions. Etodolac is used with caution in patients taking blood thinning medications ( anticoagulants ), such as warfarin (Coumadin), because it increases the risk of bleeding . Patients taking both lithium and etodolac may develop toxic blood lithium levels. Additionally, etodolac has been found to interact with certain anti-depressant medications, such as sertraline or fluoxetine , which can increase risks of stroke, heart attack, and other cardiovascular conditions. Patients also taking ciclosporin (Sandimmune) can develop kidney toxicity. Use in children has not been adequately studied. Etodolac is not habit-forming. NSAIDs should be discontinued prior to elective surgery because of a mild interference with clotting that is characteristic of this group of medicines. Etodolac is best discontinued at least four days in advance of surgery.