Standards of Laboratory Practice: Analgesic Drug Monitoring (Nacb Symposium‪)‬

Analgesic drugs comprise the largest category of pharmaceutical agents consumed by individuals in the United States. The number of over-the-counter formulations available to the consumer is staggering. Acetaminophen alone is estimated to be present in 200 brand name, over-the-counter preparations today (1). In addition, hundreds of products containing aspirin, amounting to 20 billion tablets, are consumed annually in the United States (2). Combinations with other analgesics, antihistamines, opioids, stimulants, and sedatives are available. With the recently expanded sales and marketing of over-thecounter ibuprofen and naproxen, additional increases in the already widespread use of nonsteroidal antiinflammatory drugs (NSAIDs) [3] is likely. One major concern is that the analgesic class of drugs accounted for more exposures reported to the American Association of Poison Control Centers in 1995 than did any other category of pharmaceutical agents (3). The serious nature of these exposures is underscored by the fact that they also led to the highest number of pharmaceutical drug-related deaths during that same year (3). Analgesics are used in the treatment of a wide variety of medical conditions. Their use in treating both acute and chronic pain syndromes such as cephalgia or dysmenorrhea is well recognized. With the exception of acetaminophen and tramadol, the above analgesics, also classified as NSAIDs, are indicated for the treatment of acute or chronic inflammatory diseases such as rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, acute pericarditis, and Kawasaki's disease. Antipyresis is another common indication for the administration of these agents, particularly in the pediatric age group. Acetylsalicylic acid may be useful for the prevention of thrombosis in patients with coronary artery or cerebrovascular disease, given its antiplatelet effect, and salicylate may have a role in minimizing tissue hypoxia-reperfusion injury after organ transplantation (4). Finally, increasingly important clinical applications are being realized by both NSAIDs and opioid analgesics for the treatment of postoperative and cancer pain (5).