Pharmacology of nonsteroidal antiinflammatory drugs and opioids.

Chronic pain affects up to 50 million Americans every day. Traditional treatment has included acetaminophen, nonsteroidal antiinflammatory drugs (NSAIDs), or opioids. The combination of NSAIDs and opioids can provide effective treatment for up to 90% of patients with chronic pain, but the NSAIDs have the potential for significant, even life-threatening side effects. Additionally, the nonselective cyclooxygenase inhibitors with 16,000 deaths per year in the United States might not be any safer. The opioids are great for short-term pain, but may need to be adjusted or changed frequently due to the development of tolerance. Understanding of the mechanism of opioids and NSAIDs has improved greatly over the past decade, but is still incomplete.