Level 1: Likely reliable evidence
Seventy-nine adults with osteoarthritis pain for at least one month were enrolled in a trial program to compare sustained-release paracetamol (acetaminophen) 1.33 g three times daily vs. celecoxib (Celebrex) 200 mg once daily (or twice daily if patient was already using celecoxib) (Rheumatology. 2007;46:135-140). Treatments were given for two weeks each in three paired cycles for a total of 12 weeks. Placebos were given as alternate drug to maintain double-blinding. The trial was stopped early when the Australian Therapeutic Goods Administration directed all celecoxib research to stop. The analysis included 41 patients who completed all three cycles; 20 patients did not start the trials and 18 patients completed only one or two cycles.
Pain scores were similar with both treatments in 24 patients (59%); 10 patients (24%) had reduced pain with celecoxib and two patients (5%) had reduced pain with paracetamol. Twenty-six patients (63%) had similar functional limitation scores with both treatments, while celecoxib was associated with lower functional limitation in two patients (5%).
The majority of patients (N=28, 68%) did not prefer one treatment over the other, while nine patients (22%) preferred celecoxib. The totals did not reach 100% due to incomplete data. Overall response was similar comparing both treatments in 33 patients (80%); several patients (17%) had better overall response with celecoxib, and one patient (2%) had better overall response with paracetamol.