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Biomedical subjects

R W Houde

Publications and source records attributed to R W Houde.

At least 37 records · Page 2Linked to original sources

Clinical analgesic assay of sublingual buprenorphine and intramuscular morphine.

A six-point, incomplete block assay of sublingual buprenorphine and intramuscular morphine has been carried out, providing valid relative potency estimates of the two drugs in terms of total relief on both categorical and visual analog scales. Sublingual buprenorphine was about 15.5 times as potent as intramuscular morphine in terms of these total relief estimates. Similar relative potency estimates were obtained using first-dose-only data. There was no evidence of interaction by day in the crossover data, and the crossover study proved more efficient and provided tighter confidence limits. Sublingual buprenorphine produced a lower peak effect than intramuscular morphine. At equivalent peak effects, it produced longer-lasting analgesia. Side effect occurrence was roughly comparable for the two drugs, and no evidence of narcotic antagonist activity was seen after buprenorphine. The six-point assay proved to be effective in defining the dose-effect curves and relative potencies of the two drugs.

Administration, Oral↗

Analgesic and mood effects of heroin and morphine in cancer patients with postoperative pain.

We designed a study to determine the relative analgesic potency of intramuscular heroin and morphine and to compare mood and side effects in 166 cancer patients with postoperative pain. Heroin was about twice as potent as morphine (95 per cent confidence limits, 1.6 to 2.6 times) in graded-dose, twin-crossover assays. Heroin provided an analgesic peak effect earlier than morphine (1.2 plus or minus 0.08 and 1.5 plus or minus 0.10 hours, respectively [mean plus or minus S.E.M.]). Doses with equal analgesic effects provided comparable improvements in various elements of mood, particularly feelings of peacefulness. Peak mood improvement occurred earlier after heroin than after morphine (1.2 plus or minus 0.10 and 1.8 plus or minus 0.13 hours, respectively). Both analgesia and mood improvement were less sustained after heroin at doses providing equal peak analgesic effects. The drugs shared the most common side effects, with no marked differences in their occurrence; sleepiness was the most frequent side effect after both drugs (46 per cent with each). Heroin has no apparent unique advantages or disadvantages for the relief pain in patients with cancer.

Clinical Trials as Topic↗

Relative analgesic potency of intramuscular heroin and morphine in cancer patients with postoperative pain and chronic pain due to cancer.

Heroin hydrochloride is approximately twice as potent as morphine sulfate, and acts slightly faster but for a shorter duration than morphine. Although patients with chronic pain due to advanced cancer differ from cancer patients with postoperative pain in terms of their degree of tolerance to the analgesic effects of morphine and heroin and their reports of various elements of mood, there is, thus far, no indication that heroin has any unique advantage over morphine in terms of side effect occurrence or effects on mood at equianalgesic doses. Both drugs improve mood provided they are administered in doses which result in analgesia. While there appears to be some slight difference in the spectrum of side effects observed after heroin as compared to morphine, heroin and morphine share the most common side effects. The incidence of side effects following both drugs appear to be highest among those effects which are primarily somatic and undesirable. The use of visual analog scales concurrent with categorical pain and pain relief scores provides a means for the finer estimation of relative analgesic potency and time action. The results of these studies are in general agreement with those of other investigators. Where apparent differences exist they can usually be explained on the bases of differences in methods and subject populations.

Adult↗

Relative analgesic potency of oral zomepirac and intramuscular morphine in cancer patients with postoperative pain.

A twin crossover assay of oral zomepirac and intramuscular morphine was completed in 159 cancer patients with postoperative pain. Zomepirac was a surprisingly effective oral analgesic in these patients, 100 mg orally being roughly equivalent to 16 mg intramuscular morphine. Time-effect data indicate that the peak effect for oral zomepirac may occur slightly later than that for morphine but that zomepirac is relatively rapidly effective after oral administration. Side effect occurrence was roughly in the same range for both drugs, with drowsiness, nausea, dry mouth, and feelings of weakness being observed after both drugs while sweating was observed more frequently after zomepirac. The assay further provided a demonstration of the effectiveness of the twin crossover design as a clinical assay method, providing increased sensitivity of crossover data in a patient population available for only a limited number of study treatments.

Administration, Oral↗

beta-Endorphin: analgesic and hormonal effects in humans.

The pharmacokinetics and the hormonal, analgesic, and behavioral effects of several doses of human beta-endorphin were evaluated after intravenous administration to three patients and intracerebroventricular administration to one patient with pain caused by cancer. These effects were compared to the hormonal effects of intravenously administered morphine sulfate in two patients and an enkephalin analog in two baboons. The mean terminal half-life after intravenous administration of 5 or 10 mg of human beta-endorphin to three patients was 37 min; the mean volume of distribution was 178 ml/kg, and the metabolic clearance rate was 3.2 (ml/min)/kg. The half-life of beta-endorphin in cerebrospinal fluid after intracerebroventricular administration was 93 min, and the volume of distribution was 0.74 ml/kg. A rapid rise in plasma prolactin followed both intravenous and intracerebroventricular beta-endorphin. Intravenous administration did not affect plasma growth hormone, but intracerebroventricular administration suppressed plasma growth hormone. No significant change in plasma growth hormone was noted after intravenous administration of morphine to humans, but plasma growth hormone decreased in one baboon after administration of the enkephalin analog. beta-Endorphin-stimulated release of prolactin occurred at doses lower than those required to produce analgesic and other behavioral effects. When both hormonal and analgesic effects were observed (after 7.5 mg were given intracerebroventricularly), the onset of the hormonal response slightly preceded the analgesic and behavioral responses. These studies suggest that the hormonal effects of beta-endorphin are species dependent and are similar to those of morphine. Hormonal and analgesic effects of beta-endorphin appear to result from the activation of opiate receptors that differ in their locations and characteristics.

Adult↗

Relative analgesic potency of intramuscular heroin and morphine in cancer patients with postoperative pain: a preliminary report.

The results of this study in postoperative patients have, thus far, revealed little that was not expected from a review of the literature. Heroin hydrochloride appears to be about two to three times more potent than morphine sulfate as an analgesic, to act more promptly and to have a slightly shorter duration of action. There is a suggestion that heroin may have a somewhat different spectrum of side effects and mood effects compared to morphine, but the effects of both drugs on mood were inversely correlated with the patients' feelings at the time of drug administration. Regardless, as a group, patients responded to both drugs with significantly improved moods. A lag time between the peak intensity of analgesic and mood effects of both heroin and morphine suggest a dissociation between these effects. Whether or not these early impressions will be reinforced as this study proceeds, and whether or not the effects of the drugs in patients with chronic pain due to advanced cancer will be any different than in these patients with postoperative pain, remains to be seen.

Affect↗

Clinical analgesic assay of oral zomepirac and intramuscular morphine.

Zomepirac appears to be an unexpectedly effective oral, non-opioid analgesic. The relative potency of oral zomepirac is roughly 1/5 to 1/8 that of intramuscular morphine. Visual analogues of pain relief offer a reliable alternative to verbal categorical scales, and may provide some advantages in assays of peak drug effect, and in relatively small patient populations.

Administration, Oral↗

Analgesic studies of codeine and oxycodone in patients with cancer. II. Comparisons of intramuscular oxycodone with intramuscular morphine and codeine.

The relative analgesic potency of single graded intramuscular doses of oxycodone and morphine was evaluated in a double-blind study in patients with chronic pain due to cancer. When both intensity and duration of analgesia are considered (total analgesic effect), oxycodone was 2/3 to 3/4 as potent as morphine, while in terms of peak analgesia, it was 8/10 to equipotent. In doses producing equivalent peak effect, oxycodone had a shorter duration of action than morphine. Intramuscular oxycodone was also compared to intramuscular codeine in a similar patient group. In terms of total analgesic effect, oxycodone was 10 times as potent as codeine, while in terms of peak analgesia it was 12 times as potent. These relative potency relationships of oxycodone, taken in conjunction with the oral/parenteral potency ratios of codeine and oxycodone established in the previous paper and several previous relative potency assays involving morphine, oxymorphone and codeine, demonstrate a highly consistent pattern of analgesic structure-activity relationships encompassing morphine, oxymorphone, codeine and oxycodone. The results of these studies do not appear to support the hypothesis that, in man, the analgesic activity of codeine is due to its O-demethylation to morphine.

Adult↗

Analgesic studies of codeine and oxycodone in patients with cancer. I. Comparisons of oral with intramuscular codeine and of oral with intramuscular oxycodone.

The relative analgesic potency of oral and intramuscular codeine was evaluated in a double-blind crossover comparison of graded single doses in patients with chronic pain due to cancer. When both duration and intensity of analgesia are considered (total effect), oral codeine was 6/10 as potent as the intramuscular form. This is a high oral/parenteral analgesic relative potency ratio compared with morphine, metopon and oxymorphone and correlates well with the results of recent studies which have determined the oral vs. intramuscular bioavailability of codeine in man. Oral and intramuscular oxycodone were also compared in a similar patient group. Like codeine, oxycodone retained at least 1/2 of its analgesic activity when administered orally. We hypothesize that the high oral/parenteral relative potency ratios of codeine and oxycodone relative to morphine and its congeners are not due to more efficient absorption after oral administration, but rather that methylation at position 3 in codeine and oxycodone protects these drugs from rapid first-pass metabolism.

Administration, Oral↗

Comparisons of the analgesic effects of oral and intramuscular oxymorphone and of intramuscular oxymorphone and morphine in patients with cancer.

The relative analgesic potency of oral and intramuscular oxymorphone was evaluated in a double-blind crossover comparison of graded single doses in patients with chronic pain due to cancer. When both duration and intensity of analgesia are considered (total effect), oral oxymorphone was 1/6 as potent as the intramuscular form. In terms of peak effect, however, oral oxymorphone was only 1/14 as potent. These values are almost identical to those obtained in a previous study comparing oral with intramuscular morphine. The analgesic effect of oral oxymorphone rose to a peak later and had a longer duration than the effect of intramuscular oxymorphone. Intramuscular oxymorphone and morphine were also compared in a similar patient group. Intramuscular oxymorphone proved to be 8.7 times as potent as morphine in terms of total analgesic effect and 13 times as potent in terms of peak effect. In roughly equinalgesic doses, the occurrence of side effects was qualitatively and quantitatively similar for oral and intramuscular oxymorphone and for intramuscular oxymorphone and morphine.

Administration, Oral↗