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Biomedical subjects

S L Wallenstein

Publications and source records attributed to S L Wallenstein.

30 records · Page 2Linked to original sources
PubMed1978

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↗
PubMed1978

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↗
PubMed1977

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↗
PubMedDate not supplied

Crossover trials in clinical analgesic assays: studies of buprenorphine and morphine.

Analgesic studies of buprenorphine, a thebaine derivative and potent partial narcotic agonist, were carried out in patients with cancer who had postoperative or chronic pain. Intramuscular buprenorphine was compared with intramuscular morphine in a series of sequentially related, twin crossover assays and was found to be about 25 times as potent as morphine. Side effects were essentially morphine-like. In a second assay, the acceptability and analgesic activity of sublingual buprenorphine was studied in a 6-dose, balanced, incomplete block assay, a modification of the twin crossover design employed in the all-intramuscular trial. Sublingual buprenorphine was found to be about 15 times as potent as intramuscular morphine and was well accepted by our patients. The 4-dose twin crossover trial in which doses are adjusted sequentially is more flexible in that a wide range of doses may be studied, but it lacks the ability of the 6-dose design to provide estimates of the curvature of the dose-response slopes of the study drugs. When first-dose-only data were analyzed as parallel group assays, the main difference in results compared with the crossover studies was a decrease in efficiency and sensitivity.

Administration, Oral↗