Evolving therapeutic strategies to improve nonsteroidal anti-inflammatory drug safety

Nonsteroidal anti-inflammatory drugs (NSAIDs) possess potent anti-inflammatory and analgesic properties through inhibition of cyclooxygenase enzymes (COX-1 and COX-2), which are responsible for synthesis of proinflammatory mediators. NSAIDs are frequently used for treatment of acute and chronic pain conditions. However, their use is associated with serious dose-dependent gastrointestinal (GI), cardiovascular, renal, and hepatic adverse effects, which pose a serious clinical concern for both patients and physicians. During the past 2 decades, approaches to improving the tolerability of NSAIDs were mainly directed toward discovery of COX-2 selective NSAIDs (coxibs), which were expected to minimize the risk of GI injury. Unfortunately, the results from multiple clinical studies have shown that treatment with coxibs may increase the risk for cardiovascular complications. This review summarizes current strategies used to reduce the toxicity of NSAIDs and outlines novel therapeutic approaches still in preclinical development. To minimize the risk of GI ulcerations and bleeding, combination therapies with gastroprotective agents are currently recommended. The new therapeutic agents anticipated to have similar effects include nitric oxide- and hydrogen sulfide-releasing NSAIDs. Novel manufacturing technologies enhance dissolution and absorption of NSAID products, allowing for their administration at low doses, which could lead to improved drug tolerability without diminishing the analgesic and anti-inflammatory efficacy of NSAIDs. This principle is in line with the current recommendation by the US Food and Drug Administration that NSAIDs should be used at the lowest effective dosage. Finally, NSAID formulations targeted directly to the site of inflammation are expected to reduce systemic drug exposure and thus decrease the risk of systemic adverse effects.