Faculty Bibliography

Positron emission tomography with 11C-2-deoxyglucose was used to determine the test-retest variability of regional cerebral glucose metabolism in 22 young normal right-handed men scanned twice in a 24-h period under baseline (resting) conditions. To assess the effects of scan order and time of day on variability, 12 subjects were scanned in the morning and afternoon of the same day (a.m.-p.m.) and 10 in the reverse order (p.m.-a.m.) with a night in between. The effect of anxiety on metabolism was also assessed. Seventy-three percent of the total subject group showed changes in whole brain metabolism from the first to the second measurement of 10% or less, with comparable changes in various cortical and subcortical regions. When a scaling factor was used to equate the whole brain metabolism in the two scans for each individual, the resulting average regional changes for each group were no more than 1%. This suggests that the proportion of the whole brain metabolism utilized regionally is stable in a group of subjects over time. Both groups of subjects had lower morning than afternoon metabolism, but the differences were slight in the p.m.-a.m. group. One measure of anxiety (pulse at run 1) was correlated with run 1 metabolism and with the percentage of change from run 1 to run 2. No significant run 2 correlations were observed. This is the first study to measure test-retest variability in cerebral glucose metabolism in a large sample of young normal subjects. It demonstrates that the deoxyglucose method yields low intrasubject variability and high stability over a 24-h period

Two randomized, double-blind, single-dose studies were conducted to assess the analgesic efficacy and safety of piroxicam for the treatment of moderate or severe postoperative pain. Study 1 evaluated the analgesic efficacy of piroxicam 20 mg compared with that of codeine sulfate 60 mg and placebo. A final patient population of 149 subjects rated pain intensity and pain relief at one half hour and one hour following treatment and then hourly for six hours, with a global assessment made at the completion of 24 hours. Piroxicam 20 mg was significantly more efficacious than placebo for all analgesic variables, including the sum of the pain intensity differences (SPID), total pain relief (TOTAL), percent SPID, duration of effect, and time to remedication. Codeine 60 mg was significantly superior to placebo for percent SPID and some hourly measures. Piroxicam 20 mg was significantly more effective than codeine 60 mg for percent SPID and a few hourly measures including time to remedication. Study 2 assessed the efficacy of piroxicam 20 mg or 40 mg compared with aspirin 648 mg and placebo. Sixty patients rated their pain intensity and relief hourly for 12 hours and at 24 hours after administration of study medication. Both doses of piroxicam were significantly more effective than placebo from Hours 2 to 12 for pain intensity difference (PID) and relief scores, as well as for SPID and TOTAL. Aspirin was significantly more effective than placebo from Hours 2 to 8 for relief and Hours 2 to 10 for PID as well as SPID and TOTAL. Piroxicam 40 mg was significantly more effective than aspirin 648 mg for SPID, TOTAL, and hourly measures beginning with Hour 6 through Hour 12. Piroxicam 20 mg was significantly better than aspirin for a few hourly measures: Hours 7 to 9 for relief and Hour 7 for PID. In addition, effects of piroxicam 20 mg had a significantly longer duration than aspirin. Similarly, piroxicam 20 mg had a significantly longer time to remedication compared with aspirin and placebo. The results of these studies provide evidence in support of the longer duration of analgesic efficacy of piroxicam compared with codeine or aspirin in patients with postoperative pain

The effect of the addition of 0.5 mg naloxone on the analgesic efficacy of pentazocine 50 mg was studied. A single oral dose of either pentazocine, the combination of pentazocine plus naloxone, or placebo was given in a randomized double-blind parallel group study. The study sample consisted of 48 patients with moderate pain and 76 patients with severe pain resulting from episiotomy, cesarean section, or gynecological surgery. An analysis of the entire sample showed both pentazocine and the combination to be significantly more effective than placebo for all measures, including global assessments. In addition, the combination was significantly less efficacious than pentazocine for the sum of the pain intensity difference (SPID), percentage of the sum of the pain intensity difference (%SPID), and for relief and pain intensity difference (PID) at the fourth hour. Because there was a significant interaction between drug and baseline pain intensity for the variable SPID, comparisons were made between pentazocine and the combination within each baseline pain intensity group. For patients with moderate baseline pain, the combination produced significantly less pain relief than pentazocine for SPID and for relief and PID at hours 3 and 4. In patients with severe baseline pain, there was no significant difference between pentazocine and the combination of pentazocine plus naloxone. Further studies are needed to confirm the suggestion that naloxone taken orally may decrease the analgesia achieved with pentazocine; clinicians should be aware of this possibility

Our purpose was to compare the analgesic efficacy and safety of single oral doses of the combination of ibuprofen 400 mg plus codeine 60 mg and the combination of ibuprofen 200 mg plus codeine 30 mg with ibuprofen 400 mg alone, codeine sulfate 60 mg alone, and placebo. One hundred ninety-five patients with severe pain resulting from episiotomy, cesarean section, or gynecologic surgery completed a randomized, double-blind, stratified, parallel-group study. Patients were observed during a 4-hour period after medication. Based on the sum of the pain intensity differences (SPID), total pain relief (TOTPAR), and most of the hourly direct measures of pain and relief, both doses of the combination and ibuprofen 400 mg alone were statistically superior to placebo. Codeine 60 mg was statistically superior to placebo based on TOTPAR, the global ratings, and a few hourly measures. The mean effect of the combination of ibuprofen 400 mg plus codeine 60 mg was significantly superior to the mean effect of ibuprofen 400 mg alone 1/2, 1, and 2 hours after medication and to the mean effect of ibuprofen 400 mg alone and codeine 60 mg alone for SPID, TOTPAR, and other measures as well. The low-dose combination was significantly more effective than codeine 60 mg for a few hourly measures but was not significantly superior to ibuprofen 400 mg. Based on these findings it appears that the combination of ibuprofen 400 mg plus codeine 60 mg, particularly in the first few hours after medication, is more efficacious than its constituents