Clinical consequences of nonnarcotic analgesic use

Abstract

The accuracy of the economic analysis of the selected adverse events evaluated by McGoldrick and Bailie is questionable. The quantitative perspective on the economics of the adverse events associated with nonnarcotic analgesic use proposed by these authors is limited by the fact that they have combined data on over 30 different NSAIDs into a single value for comparison with two single-entity agents: acetaminophen and aspirin. The relative prevalence of major organ system toxicities varies markedly among the NSAIDs, and this variance invalidates the use of a class conclusion approach. Their conservative incidence estimates, the lack of data in some areas (i.e., hepatic injury), and the exclusion of combination analgesics further limit the utility of their conclusions. However, it is difficult to argue authoritatively that the relative costs of toxicities associated with the three analgesic classes they reviewed are not representative. The ultimate question is, "What is the optimal analgesic for a given patient?" This question can be addressed only if one considers the underlying cause of pain, its chronicity/acuity, the patient's concurrent disease states, if any, and the potential for drug interactions with the patient's concomitant medications. McGoldrick and Bailie concluded on an economic basis that acetaminophen is the analgesic of choice for most patients, including those with impaired renal function. This recommendation is in agreement with those of the Analgesics and the Kidney Ad Hoc Committee of the National Kidney Foundation. It also would seem prudent to use acetaminophen as the first-line agent for those patients in whom aspirin and NSAID use should be avoided or used only with caution along with frequent monitoring of renal function, blood pressure, electrolytes, and/or coagulation status. Thus, there is little to no controversy in their recommendation to initiate treatment with acetaminophen. The authors, however, also suggested that switching patients from an NSAID to acetaminophen would result in significantly decreased costs and morbidity. These authors, however, did not address one key issue that impacts their economic analysis: the relative efficacy of acetaminophen and NSAIDs. If efficacy is similar, then the risk/benefit ratio and economic consequences would favor the use of acetaminophen. However, if many patients are receiving NSAIDs because they did not obtain pain relief with the use of acetaminophen, there would be neither rationale or likely benefit with a change in therapy to acetaminophen. Finally, McGoldrick and Bailie did not evaluate an issue that has perhaps the most far-reaching consequence. Many OTC analgesics are currently marketed as combinations of aspirin, acetaminophen, salicylamide, or caffeine (Table 2). Although the intent of these combinations was [Table: see text] to enhance efficacy while minimizing adverse events, it is now apparent that at least concerning adverse events, the goal was not achieved. Therefore, in light of the markedly higher risk for renal injury with combination analgesics, these agents should be withdrawn from the marketplace. While some might argue that patient education is the key and that addition of an explicit warning on the label of OTC combination products should be an adequate intervention, this agreement is not supported by the Belgium experience. The removal of combination analgesics from the OTC marketplace could be accomplished by governmental action, such as the ban on phenacetin over 10 years ago. Alternatively, pharmacists could no longer sell these products and counsel patients on the rational use of OTC analgesics. The choice among single-entity agents could then be individualized on the basis of patient's current medical status and the adverse event profile of the available agents.