Lack of efficacy of acetaminophen in treating symptomatic knee osteoarthritis: a randomized, double-blind, placebo-controlled comparison trial with diclofenac sodium. Comparison of naproxen and acetaminophen in a two-year study of treatment of osteoarthritis of the knee. A randomized, double blind, placebo controlled trial of intravenous loading with S-adenosylmethionine (SAM) followed by oral SAM therapy in patients with knee osteoarthritis. The effectiveness of exercise therapy in patients with osteoarthritis of the hip or knee: a randomized clinical trial. Efficacy of rofecoxib, celecoxib, and acetaminophen in osteoarthritis of the knee: a randomized trial. Comparison of an antiinflammatory dose of ibuprofen, an analgesic dose of ibuprofen, and acetaminophen in the treatment of patients with osteoarthritis of the knee. A randomized, double-blind, crossover clinical trial of diclofenac plus misoprostol versus acetaminophen in patients with osteoarthritis of the hip or knee. Patient Preference for Placebo, Acetaminophen (paracetamol) or Celecoxib Efficacy Studies (PACES): two randomised, double blind, placebo controlled, crossover clinical trials in patients with knee or hip osteoarthritis. Analgesic efficacy and safety of nonprescription doses of naproxen sodium compared with acetaminophen in the treatment of osteoarthritis of the knee.
Recommendations state that acetaminophen should be used in preference to nonsteroidal anti-inflammatory drugs in the initial treatment of symptomatic osteoarthritis (OA) of the hip or knee, because of lesser toxicity and the pervasive belief that acetaminophen is not only effective in treating OA pain but is of equal analgesic efficacy as nonsteroidal anti-inflammatory drugs.
                This was a randomized, double-blind, placebo-controlled trial of diclofenac sodium, 75 mg twice daily, vs acetaminophen, 1000 mg 4 times daily, in 82 subjects with symptomatic OA of the medial knee. Osteoarthritis was quantitated radiographically, and subjects met stringent baseline pain criteria. The primary evaluation of efficacy used the Western Ontario and McMaster Universities Osteoarthritis Index, with evaluations at screening, baseline, and 2 and 12 weeks after treatment. Intention-to-treat analysis was used.
                Twenty-five subjects were randomized to diclofenac, 29 to acetaminophen, and 28 to placebo. The groups were closely matched for age, sex, body mass index, prior use of OA medications, baseline pain, and radiographic features. At 2 and 12 weeks, clinically and statistically significant (P<.001) improvements were seen in the diclofenac-treated group; however, no significant improvements were seen in the acetaminophen-treated group (P =.92 at 2 weeks and.19 at 12 weeks). Stratification of subjects according to baseline pain, prestudy OA medication, and radiographic grade showed no clear pattern of preferential response to diclofenac, and did not reveal a subset of subjects who responded to acetaminophen.
                Diclofenac is effective in the symptomatic treatment of OA of the knee, but acetaminophen is not. A review of the literature reveals that there is scanty published evidence for a therapeutic effect of acetaminophen relative to placebo in patients with OA of the knee, because most published studies use active comparators (ie, nonsteroidal anti-inflammatory drugs) only. The advocacy of acetaminophen use in subjects with OA of the knee should be reconsidered pending further placebo-controlled studies. To compare the relative safety and efficacy of naproxen and acetaminophen in the treatment of osteoarthritis (OA) of the knee. The major outcome measures were radiographic progression and withdrawal from the trial due to lack of efficacy.
                One hundred seventy-eight patients with OA of the knee were enrolled in a 2-year prospective, controlled, double-blind multicenter trial and were randomly assigned to receive acetaminophen (ACT) or naproxen (NPX) treatment.
                After 6 weeks of treatment, modest improvement in pain on motion and in physician's global assessment was seen in both the ACT and the NPX groups, and the NPX group also had modest improvement in pain at rest and in 50-foot walk time. Sixty-two patients completed the 2-year study. Among these patients, radiographic progression was similar in the 2 treatment groups. Withdrawal from the trial due to lack of drug efficacy was slightly more frequent among patients in the ACT group (22% versus 16%), but withdrawal due to adverse drug effects was slightly more common in the NPX group (23% versus 18%).
                The efficacy of ACT treatment and NPX treatment was similar, although it was slightly better for NPX. The toxicity rate was slightly lower with ACT. However, the high rate of withdrawal in both treatment groups suggests that neither is satisfactory for the treatment of OA. We evaluated the effectiveness and rapidity of onset of S-adenosylmethionine (SAM), administered as daily intravenous boluses of 400 mg for 5 days, followed by oral tablets, 200 mg thrice daily for 23 days, versus a matching placebo regimen, in the treatment of 81 patients with symptomatic knee osteoarthritis (OA).
                The study was bicentric, randomized, double blinded, and placebo controlled. Patients underwent a 7-day washout of arthritis medications prior to initiation of this study treatment. Major outcome measures were the Stanford Health Assessment Questionnaire disability and pain scales, and supplemental visual analog scales for rest and walking pain.
                At one site, patients had milder OA, the baseline characteristics of the treatment groups were well matched, and the SAM treated group showed significantly greater reduction in overall pain and rest pain (p < 0.05) than the placebo treated group. At the other site, the patients had more severe OA, randomization yielded markedly different treatment groups, and the response to treatment did not differ between groups. Onset of SAM effect was seen as early as 14 days after the start of treatment.
                SAM may be an effective treatment for some patients with symptomatic knee OA, and merits further study. Intravenous loading before oral maintenance therapy may be advantageous. To determine the effectiveness of exercise therapy in patients with osteoarthritis (OA) of the hip or knee.
                A randomized single blind, clinical trial was conducted in a primary care setting. Patients with hip or knee OA by American College of Rheumatology criteria were selected. Two intervention groups were compared. Both groups received treatment from the patients' general practitioner, including patient education and medication if necessary. The experimental group also received exercise therapy from a physiotherapist in primary care. The treatment period was 12 weeks. The main outcome measures were pain, medication use (nonsteroidal antiinflammatory drugs, NSAID) and observed disability.
                A total of 201 patients were randomized. Exercise therapy was associated with a reduction of pain in the past week (difference in change -17.0; 95% CI -23.6, -10.4) and observed disability (-0.19; 95% CI -0.38; -0.01). Effect sizes were medium (0.58) and small (0.28), respectively. No effect of exercise therapy was found for the use of NSAID. Additional beneficial effects (p = 0.05) were found for the use of paracetamol (effect size 0.33), global effect as perceived by the patient (effect size 0.68), and muscle strength of the hip (effect size 0.34).
                After 12 weeks, exercise therapy is effective in reducing pain and disability. The size of the effects is medium and small, respectively. Osteoarthritis (OA) is often treated with nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, or specific inhibitors of cyclooxygenase 2 (COX-2).
                To assess the relative therapeutic efficacy of rofecoxib, celecoxib, and acetaminophen in adults with OA.
                Randomized, parallel-group, double-blind trial, conducted from June 1999 to February 2000, in 29 clinical centers in the United States.
                Three hundred eighty-two patients aged at least 40 years who had OA of the knee that was previously treated with NSAIDs or acetaminophen.
                Patients were randomly assigned to receive rofecoxib, 12.5 mg/d (n = 96); rofecoxib, 25 mg/d (n = 95); celecoxib, 200 mg/d (n = 97); or acetaminophen, 4000 mg/d (n = 94) for 6 weeks.
                Assessments over days 1 to 6 and over 6 weeks included pain on walking, night pain, pain at rest, and morning stiffness as measured on a Western Ontario McMaster Universities Osteoarthritis Index (100-mm visual analog scale [VAS]) and global response to therapy compared among 4 treatment groups.
                79% of patients completed the study. More patients treated with acetaminophen discontinued early due to lack of efficacy than patients treated with COX-2 inhibitors (31% vs 18%-19%). Efficacy assessed in the first 6 days of therapy showed greatest response to rofecoxib, 25 mg/d, followed by rofecoxib, 12.5 mg/d, celecoxib, and acetaminophen, respectively, in terms of relief of pain on walking (-32.2, - 29.0, - 26.4, and -20.6 mm change on the VAS; P</=.04 for all others vs acetaminophen; P =.05 for 25-mg rofecoxib vs celecoxib), rest pain (-21.8, - 18.6, - 15.5, and - 12.5 mm; P</=.02 for either dose of rofecoxib vs acetaminophen and P =.02 for rofecoxib, 25 mg/d, vs celecoxib), night pain (-25.2, - 22.0, - 18.7, and - 18.8 mm; P =.04 for rofecoxib, 25 mg/d, vs both acetaminophen and celecoxib), and morning stiffness (-30.4, - 28.4, - 25.7, and - 20.9 mm; P</=.02 for either dose of rofecoxib vs acetaminophen). Over 6 weeks, rofecoxib, 25 mg/d, provided greatest response for night pain (P<.002 vs celecoxib and P =.006 vs acetaminophen and P =.02 vs rofecoxib, 12.5 mg/d), composite pain subscale (P</=.03 vs all other treatments), stiffness subscale (P</=.04 vs celecoxib and acetaminophen), and physical function subscale (P =.001 vs acetaminophen). Global responses over 6 weeks showed a similar pattern (good or excellent response at week 6: 60%, 56%, 46%, and 39%, respectively; P</=.03 for rofecoxib, 25 mg/d, vs celecoxib and acetaminophen; P =.02 for rofecoxib, 12.5 mg/d, vs acetaminophen). All treatments were generally safe and well tolerated.
                Rofecoxib, 25 mg/d, provided efficacy advantages over acetaminophen, 4000 mg/d, celecoxib, 200 mg/d, and rofecoxib, 12.5 mg, for symptomatic knee OA. The optimal short-term, symptomatic therapy for osteoarthritis of the knee has not been fully determined. Accordingly, we compared the efficacy of a nonsteroidal antiinflammatory drug, ibuprofen, given in either an antiinflammatory dose (high dose) or an analgesic dose (low dose), with that of acetaminophen, a pure analgesic.
                In a randomized, double-blind trial, 184 patients with chronic knee pain due to osteoarthritis were given either 2400 or 1200 mg of ibuprofen per day or 4000 mg of acetaminophen per day. They were evaluated after a washout period of three to seven days before the beginning of the study, and again after four weeks of treatment. The major measures of outcome included scores on the pain and disability scales of the Stanford Health Assessment Questionnaire (range of possible scores, 0 to 3), scores on the visual-analogue scales for pain at rest and pain while walking, the time needed to walk 50 ft (15 m), and the physician's global assessment of the patient's arthritis.
                Seventy-eight percent of the patients completed four weeks of therapy. No significant differences were noted among the three treatment groups with respect to failure to complete the trial because of noncompliance or adverse events. All three groups had improvement in all major outcome variables, and the groups did not differ significantly in the magnitude of improvement in most variables. The mean improvement (change) in the scores on the pain scale of the Health Assessment Questionnaire was 0.33 with acetaminophen (95 percent confidence interval, 0.14 to 0.52), 0.30 with the low dose of ibuprofen (95 percent confidence interval, 0.09 to 0.51), and 0.35 with the high dose of ibuprofen (95 percent confidence interval, 0.13 to 0.57). Side effects were minor and similar in all three groups.
                In short-term, symptomatic treatment of osteoarthritis of the knee, the efficacy of acetaminophen was similar to that of ibuprofen, whether the latter was administered in an analgesic or an antiinflammatory dose. To perform a randomized, double-blind, crossover clinical trial of diclofenac + misoprostol versus acetaminophen in ambulatory patients with osteoarthritis of the hip or knee.
                Patients in 12 ambulatory care settings were eligible if they were age >40 years and if they had Kellgren/Lawrence radiographic grade 2-4 osteoarthritis of the knee or hip and a score of > or =30 mm on a 100-mm visual analog pain scale. Patients were randomized to one of two groups, 75 mg diclofenac + 200 microg misoprostol twice daily or 1,000 mg acetaminophen 4 times daily (each for 6 weeks), and were then crossed over to the other treatment for 6 weeks. A placebo was included in each treatment regimen to enable double blinding. The primary outcome measures were the Western Ontario and McMaster Universities Osteoarthritis Index and the visual analog pain scale of the Multidimensional Health Assessment Questionnaire. Safety was assessed using a standard form to review adverse events.
                We enrolled 227 patients, of whom 218 provided data for the first treatment period and 181 provided data for both treatment periods. Significantly higher levels of improvement in the primary outcomes were seen for diclofenac + misoprostol than for acetaminophen (P < 0.001). Adverse events were more common when patients took diclofenac + misoprostol (P = 0.046). Diclofenac + misoprostol was rated as "better" or "much better" by 57% of the 174 patients who provided such ratings for both treatment periods, while acetaminophen was rated as "better" or "much better" by 20% of these patients, and 22% reported no difference (P < 0.001). Differences favoring diclofenac + misoprostol over acetaminophen were greater in patients with more severe osteoarthritis according to baseline pain scores, radiographs, or number of involved joints.
                Patients with osteoarthritis of the hip or knee had significantly greater improvements in pain scores over 6 weeks with diclofenac + misoprostol than with acetaminophen, although patients with mild osteoarthritis had similar improvements with both drugs. Acetaminophen was associated with fewer adverse events. Acetaminophen (paracetamol) is recommended as the initial pharmacological treatment for knee or hip osteoarthritis. However, survey and clinical trial data indicate greater efficacy for non-steroidal anti-inflammatory drugs and cyclo-oxygenase-2 specific inhibitors.
                Two randomised, double blind, placebo controlled, crossover multicentre clinical trials, Patient Preference for Placebo, Acetaminophen or Celecoxib Efficacy Studies (PACES).Patients: Osteoarthritis of knee or hip.Intervention: "Wash out" of treatment; randomisation; 6 weeks of celecoxib 200 mg/day, acetaminophen 1000 mg four times a day, or placebo; second "wash out;" crossover to 6 weeks of second treatment.Measurements: Western Ontario McMaster Osteoarthritis Index (WOMAC), visual analogue pain scale, patient preference between two treatments.
                Celecoxib was more efficacious than acetaminophen in both periods in both studies; WOMAC and pain scale scores differed at p<0.05 in period II and both periods combined of PACES-a and in periods I and II and both periods combined in PACES-b, but not in period I of PACES-a. Acetaminophen was more efficacious than placebo, generally p<0.05 in PACES-b, and >0.05 in PACES-a. Patient preferences were 53% celecoxib v 24% acetaminophen in PACES-a (p<0.001) and 50% v 32% in PACES-b (p = 0.009); 37% acetaminophen v 28% placebo in PACES-a (p = 0.340) and 48% v 24% in PACES-b (p = 0.007). No clinically or statistically significant differences were seen in adverse events or tolerability among the three treatment groups.
                Greater efficacy was seen for celecoxib v acetaminophen v placebo, while adverse events and tolerability were similar. Variation in results and statistical significance in the two different trials are of interest. Nonprescription doses of naproxen sodium, acetaminophen, and placebo were compared to determine their efficacy and safety in osteoarthritis of the knee. In two identical multicenter, randomized, double-blind, placebo-controlled, multidose, parallel-design studies, patients with osteoarthritis aged (mean +/- SD) 60.6 +/- 12.8 years were randomized to daily doses of 660 mg naproxen sodium (440 mg naproxen sodium in patients >or=65 years), 4000 mg acetaminophen, or placebo for 7 days. Naproxen sodium (440/660 mg) provided significantly greater improvements in pain at rest, on passive motion, on weight-bearing, stiffness after rest (morning), day and night pain compared with placebo, and significantly greater relief from resting pain than acetaminophen (P < 0.05). Acetaminophen provided significantly greater improvements in day pain compared with placebo. Daily evaluations showed naproxen sodium (440/660 mg) provided superior pain relief to acetaminophen and was significantly better than acetaminophen at reducing difficulties experienced in walking several blocks and difficulties in bending, lifting, and stooping. Naproxen sodium (440/660 mg) and acetaminophen (4000 mg) were significantly more effective than placebo in improving mobility level, household tasks, and walking and bending. Patient and investigator evaluation scores were significantly higher in naproxen sodium and acetaminophen groups compared with placebo; no differences were observed between active treatments. Naproxen sodium and acetaminophen had similar safety profiles to placebo. Nonprescription doses of naproxen sodium (440/660 mg) effectively relieve pain and other symptoms of osteoarthritis. Naproxen sodium is an alternative in the initial treatment of osteoarthritis and may be preferred to acetaminophen as first-line therapy in patients with moderate or severe pain.
The evidence to date suggests that NSAIDs are superior to acetaminophen for improving knee and hip pain in people with OA. The size of the treatment effect was modest, and the median trial duration was only six weeks, therefore, additional considerations need to be factored in when making the decision between using acetaminophen or NSAIDs. In OA subjects with moderate-to-severe levels of pain, NSAIDs appear to be more effective than acetaminophen.