Lessons from early large-scale adoption of celecoxib and rofecoxib by Australian general practitioners

In reply: The advantage of the COX-2-selective NSAIDs (C2SNs) is the reduction in clinically significant gastrointestinal complications compared with conventional NSAIDs, but, as Florin agrees, other toxicities, including the risk of renal failure and heart failure, are similar for C2SNs and the older drugs.1 We speculated that doctors may have been more aware of the differences between the new and the conventional anti-inflammatories rather than the similarities: between 4.7% and 7.9% of patients in our study cohorts were treated with a combination of drugs which placed the patient at risk of renal complications. Florin points out that there is an approximate 50% reduction in clinically significant gastrointestinal (GI) complications with C2SNs compared with conventional NSAIDs. If, in a population, the annual incidence of serious GI complications with NSAID use is around 1.4%,2 then the absolute risk reduction is 0.7%. This means that about 140 patients would need to be treated with a C2SN for one year to prevent one serious GI complication. Messages conveyed in this way may be more pertinent to clinical decision making than a statement about relative risk reduction.

Florin also notes the problems with elderly patients who often take multiple medications, and are probably at increased risk of upper-GI events with NSAIDs. Our data demonstrated very high prescribing rates in patients who were not elderly. Over 20% of patients in our cohorts were aged less than 50 years, and over 50% were aged less than 65 years. Furthermore, between 34.5% and 61.3% had no pain medication prescribed in the 12 months before the first C2SN prescription, suggesting that C2SNs may have been used as a first-line pain medication in these patients. Quality use of medicines advocates prescribing which is safe, judicious, effective and cost-effective. Recent pharmacoeconomic studies suggest the cost-effectiveness may only be realised when prescribing of C2SNs is confined to patients who are at high risk of GI complications.3,4