ADL 8-2698, a trans-3,4-dimethyl-4-(3-hydroxyphenyl) piperidine, prevents gastrointestinal effects of intravenous morphine without affecting analgesia.

ADL-8-2698 is a novel peripherally restricted opioid antagonist that may selectively prevent opioid-induced gastrointestinal effects without reversing analgesia. Gastrointestinal transit time (lactulose hydrogen breath test) was measured in 14 volunteers with oral and intravenous placebo, oral placebo and intravenous morphine (0.05 mg x kg(-1)), and oral ADL 8-2698 (4 mg) and intravenous morphine (0.05 mg x kg(-1)) in a double blind, cross-over study. Morphine prolonged gastrointestinal transit time from 69 to 103 minutes (P = .005); this was prevented by ADL 8-2698 (P = .004). Postoperatively, 45 patients were randomly assigned in a double-blind fashion to receive ADL 8-2698 (4 mg) or placebo and intravenous morphine (0.15 mg/kg) or to receive oral and intravenous placebo. Analgesia and pupil constriction were measured. Morphine analgesia and pupil constriction were unaffected by ADL 8-2698 and differed from placebo (P < .002). We conclude that ADL 8-2698 prevents morphine-induced increases in gastrointestinal transit time by means of selective peripheral opioid anitagonism without affecting central opioid analgesia.

Comparison of the efficacy and safety of ketorolac and meperidine in the relief of dental pain.

A single-dose, randomized, double-blind study of parallel design was conducted to determine the analgesic efficacy and safety of ketorolac tromethamine in patients who experience moderate or severe pain after the surgical removal of three or more third molars, one of which was a bony-impacted mandibular molar. Meperidine hydrochloride was used as the control analgesic. In this 8-hour study, assessments were made of pain intensity, pain relief, and overall rating of the medication in 145 patients, each of whom had received an intramuscular injection of 10 mg, 30 mg, or 90 mg of ketorolac, or 50 mg or 100 mg of meperidine. The summed pain intensity and total pain relief scores showed that, at 3 and 8 hours, the effectiveness of 30 mg of ketorolac was similar to that of 90 mg ketorolac and that both of these doses were significantly more efficacious than 10-mg ketorolac, 50-mg meperidine, or 100-mg meperidine. Patients who received 30 mg or 90 mg of ketorolac gave the study medication significantly higher ratings overall than did patients who received 50 mg or 100 mg of meperidine. Significantly fewer patients treated with ketorolac reported adverse events in comparison with those treated with meperidine (17% and 59%, respectively), which suggests that it possesses a better therapeutic index than meperidine. Thus, ketorolac appears to represent an important advance in analgesic therapy.

Rofecoxib versus codeine/acetaminophen in postoperative dental pain: a double-blind, randomized, placebo- and active comparator-controlled clinical trial.

BACKGROUND: In recent studies of acute pain and primary dysmenorrhea, rofecoxib, a nonsteroidal anti-inflammatory drug that selectively targets the cyclooxygenase-2 enzyme, was found to be similar in efficacy to ibuprofen and naproxen sodium. OBJECTIVE: The purpose of this study was to determine the analgesic efficacy of a single oral dose of rofecoxib 50 mg compared with the combination of codeine 60 mg/acetaminophen 600 mg in a model of postsurgical dental pain. METHODS: In this double-blind, placebo- and active comparator-controlled, parallel-group study, patients experiencing moderate or severe pain after the surgical extraction of > or = 2 third molars, at least 1 of which was a mandibular impaction, were randomized to receive placebo, rofecoxib 50 mg, or codeine 60 mg/acetaminophen 600 mg. Patient evaluations of pain intensity, pain relief, and global assessments were recorded throughout the 24-hour period after dosing. The 2-stopwatch method was used to determine time to confirmed perceptible pain relief. The primary end point assessing overall analgesic effect was total pain relief over 6 hours (TOPAR6). Secondary end points were patient global assessment of response to therapy (PGART) at 6 hours, onset of analgesia, peak analgesic effect, and duration of analgesia. RESULTS: A total of 393 patients were enrolled; 182 received rofecoxib, 180 received codeine/acetaminophen, and 31 received placebo. The overall analgesic effect of rofecoxib 50 mg was greater than that of codeine 60 mg/acetaminophen 600 mg for TOPAR6 (12.4 vs 7.0; P < 0.001) and PGART at 6 hours (P < 0.001). The onset of analgesic effect was similar for rofecoxib and codeine/acetaminophen. Peak analgesic effect as measured by peak pain relief scores during the first 6 hours was significantly greater in the rofecoxib group compared with the codeine/acetaminophen group (P < 0.001), as was the duration of analgesic effect measured by the time to rescue analgesia (9.6 hours vs 2.3 hours, P < 0.001). Adverse events were reported in 33.0%, 46.1%, and 32.3% of patients treated with rofecoxib, codeine/acetaminophen, and placebo, respectively. The most common adverse events were nausea (6.0%, 25.0%, and 9.7%, respectively) and vomiting (3.8%, 18.3%, and 6.5%, respectively). Significantly more patients in the codeine/acetaminophen group than in the rofecoxib group experienced adverse events overall (P < 0.050) and nausea in particular (P < 0.001). CONCLUSION: In this study of moderate to severe postoperative dental pain, the analgesic efficacy of rofecoxib 50 mg was greater than that of codeine/acetaminophen, with a lower incidence of adverse events and nausea.

Analgesic efficacy of single oral doses of lumiracoxib and ibuprofen in patients with postoperative dental pain.

This randomised, double-blind study compared single dose lumiracoxib (a cyclooxygenase-2 selective inhibitor) 100 and 400 mg, ibuprofen 400 mg and placebo in patients with postoperative dental pain over 12 h. The primary efficacy variable was pain intensity difference. Lumiracoxib 400 mg and ibuprofen were superior to placebo from 1 to 12 h post dose while lumiracoxib 100 mg was superior from 1.5 to 9 h. Lumiracoxib 400 mg demonstrated the fastest median time to onset of analgesia (37.4 min) followed by ibuprofen (41.5), and lumiracoxib 100 mg (52.4; all p < or = 0.001 vs. placebo). Median time to rescue medication (h) was longer for lumiracoxib 400 mg (> or = 12), lumiracoxib 100 mg (approximately 7) and ibuprofen (approximately 8) than placebo (approximately 2; all p < or = 0.001 vs. placebo). Patients rated lumiracoxib 400 mg superior to the other active treatments (p < 0.05); lumiracoxib 100 mg was comparable with ibuprofen and superior to placebo (p < 0.001). Lumiracoxib provided rapid, effective and well-tolerated analgesia.

Development of a probabilistic blood lead prediction model.

A partially probabilistic blood lead prediction model has been developed, based on the US Environmental Protection Agency integrated exposure-uptake-biokinetic blood lead model (IEUBK model). This study translated the IEUBK model into a spreadsheet format. The uptake submodel incorporates uncertainty distributions for exposure and bioavailability parameters. The biokinetic submodel is duplicated with a table incorporating partitioning and decay of lead levels in the body. As a case study, the probabilistic model is applied to a lead exposure scenario involving a former smelter site in Sandy, Utah. The probabilistic model produces less biased estimates of means and standard deviations than the deterministic model. Parameter uncertainty is propagated in the model by the use of Monte Carlo simulation. Thus, sensitivity analysis is possible, and driving variables can be determined.

An assessment of lead absorption from soil affected by smelter emissions.

The purpose of this study was to assess the oral bioavailability of lead in soil collected from a former smelter site in Sandy, Utah, USA. Sprague-Dawley rats (approximately 4 weeks of age, 5 of each sex in group) were given either soil lead or lead acetate mixed in a purified diet (AIN-93G ™) at four different concentrations for 31 consecutive days. Food consumption measurements were used to compute mean daily lead exposures for the soil lead and lead acetate groups. The lead acetate treatment yielded higher concentrations of lead in the blood and bone than the soil lead treatment. Mean blood lead values ranged from below the detection limit (3 µg dL(-1)) to 27.25 µg lead dL(-1) for the lead acetate groups at dose levels of 0.10-2.91 mg lead kg body weight(-1) and from below the detection limit to 8.8 µg lead dL(-1) for the soil lead groups at doses of 0.11-3.43 mg lead kg body weight(-1). At these same doses, mean bone values ranged from 0.52 to 26.92 µg lead g(-1) for the lead acetate groups and from 0.64 to 13.1 µg lead g(-1) for the soil lead groups. Relative per cent bioavailability was estimated by modelling the dose-blood concentration curves for the lead acetate treatment and the dosed soil lead treatment, and then comparing doses that produce an equivalent blood lead concentration. The ratio of the doses of lead acetate and soil lead that produced the same tissue response (i.e., concentration) provided an index of relative bioavailability. For lead, the bioavailability of soil lead relative to lead acetate was 41% at a blood concentration of 6 µg lead dL(-1).