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Biomedical subjects

R I Wang

Publications and source records attributed to R I Wang.

At least 37 records · Page 2Linked to original sources
PubMed1981

Crossover and parallel study of oral analgesics.

Ten years ago, analgesics were studied using crossover designs. In recent years, analgesics have been studied only in parallel designs primarily because biostatisticians do not like crossover studies. The advantages of crossover studies are numerous: (1) patients serve as their own control; (2) there is less variability of responses among patients; and (3) a smaller number of patients is needed to provide statistically significant data. As long as crossover of treatment medications does not occur within 4 to 6 hours, the problem of carryover effect of the previous medication is insignificant or negligible. Two studies will be presented. One is a crossover study of Percodan with and without naloxone to placebo. The other is a parallel study comparing the effects of propoxyphene with naloxone to those of propoxyphene alone. The results of these studies reaffirm the value of the crossover method of evaluating analgesics.

Administration, Oral↗
PubMed1981

Reserpine and alpha-methyldopa in the treatment of tardive dyskinesia.

Thirty inpatients with evidence of tardive dyskinesia secondary to antipsychotic medications participated in this double-blind, controlled, randomized study comparing reserpine, alpha-methyldopa and placebo. Reserpine at doses of 0.75--1.5 mg daily, or alpha-methyldopa at doses of 750--1,500 mg daily, produced a statistically significant improvement in tardive dyskinesia symptomatology compared to the results obtained with placebo.

Adult↗
PubMed1981

Propoxyphene napsylate compared to methadone for opiate dependence.

When high single doses of propoxyphene napsylate (PN) were given to patients on a methadone maintenance program, results indicated that, to avoid undesirable side effects, the dose should not exceed 600 mg. However, when PN was given in divided doses (800 mg/day in two equal doses), no significant adverse reactions were noted. In the double-blind comparison of 800 mg PN in two divided doses versus 20 mg methadone, 10 mg methadone, or placebo methadone, it was found that PN (1) did not alleviate withdrawal symptoms in patients previously maintained on 20 mg methadone, (2) produced a slightly overmedicated effect in the detoxified group of ex-methadone patients, and (3) compared favorably to 10 mg methadone in suppressing withdrawal symptoms without producing evidence of overmedication in those patients previously stabilized on a methadone maintenance dose of 10 mg. It is concluded that on a mg for mg basis, PN at a dose of 80-times that of methadone will relieve withdrawal symptoms in the treatment of mildly addicted patients requiring 10 mg methadone or less per day.

Adult↗
PubMed1981

Doxpicomine in postoperative pain.

In a single-dose study the analgesic activity of 400 mg doxpicomine was compared with 4 and 8 mg morphine administered intramuscularly. Our subjects wee 43 men with moderate or severe postsurgical pain on the first postoperative day. Results of a double-blind trial indicate the analgesic activity of 400 mg intramuscular doxpicomine to be within the range of 8 mg morphine. There was no statistical significance between the effects of 400 mg doxpicomine and 8 mg morphine with the exception of half-hour data where doxpicomine was more effective than morphine. Doxpicomine has a rapid onset of analgesic action, the duration of which is equivalent to that of 8 mg morphine.

Adult↗
PubMed1981

Effect of intraventricular beta-endorphin and morphine on hypothalamic-pituitary-adrenal activity and the release of pituitary beta-endorphin.

The effects of intraventricular (i.v.t.) morphine sulfate (MS) and beta-endorphin (beta-EP) on pituitary-adrenal activity and the release of pituitary beta-EP were studied in rats. Pituitary-adrenal activity was monitored by measuring plasma corticosterone (CS) levels. 45 min after i.v.t. injection, both MS and beta-EP caused dose-related increases in plasma CS, with beta-EP being approximately ten times more potent on a molar basis. MS injected i.v.t. at 0.3, 1.0, 3.0 and 10.0 microgram did not cause a significant reduction in pituitary immunoreactive (i.r.) beta-EP, but did cause an increase in plasma i.r. beta-EP at 3 microgram of MS. beta-EP injected i.v.t. at 1.5 microgram caused a reduction of pituitary i.r. beta-EP. Since i.v.t.-injected beta-EP may have contributed to the measured plasma i.r. beta-EP, a nonimmunoreactive analog (Des-Asn20-beta c-EP) was used to assess the change in plasma i.r. beta-EP. 5 microgram of DES-Asn20-beta c-EP injected i.v.t. caused increases in plasma i.r. beta-EP and CS, as well as a 40% reduction in pituitary i.r. beta-EP. The concomitant intraperitoneal (i.p.) injection of naloxone HCl (10 mg/kg) significantly blocked the increase in plasma CS induced by 5 microgram of beta-EP. When naloxone HCl, 10 mg/kg was injected alone, a significant increase in plasma CS was found. The results indicate that i.v.t. beta-EP is more potent than MS in causing the release of pituitary ACTH and beta-EP. These findings are consistent with a role for brain endorphins in the regulation of CRF release.

Animals↗
PubMed1980

Absence of cross-tolerance to heroin in morphine-tolerant mice.

Mice implanted with morphine pellets demonstrated a 30-fold increase in tolerance to subcutaneously administered morphine but showed no cross-tolerance to subcutaneously administered heroin. When given morphine intracerebroventricularly, the mice showed no tolerance to morphine or cross-tolerance to heroin. These observations depended on the presence of the morphine pellet. If the pellets were removed prior to determinations of potency, the expected responses--tolerance to morphine and cross-tolerance to heroin--were obtained. The blood-brain barrier may be a prime site for the expression of morphine tolerance in mice.

Animals↗
PubMed1980

Enterohepatic circulation of l-alpha-acetylmethadol in the rat.

The enterohepatic circulation of the biliary metabolites of l-alpha[3H]acetylmethadol ([3H]LAAM) was studied in rats. Bile was collected for 48 hr from a biliary-cannulated donor rat after s.c. administration of [3H]LAAM. This bile containing tritium-labeled LAAM metabolites was then infused into the small intestine of a recipient rat for 48 hr and the appearance of radioactivity in bile formed in the liver of the recipient rat was monitored. Forty-eight hours after the start of infusion, 40% of the infused radioactivity had been excreted into the bile of the recipient rat, indicating extensive enterohepatic circulation of the biliary metabolites of LAAM. The data indicated that only a small percentage of the infused [3H]LAAM metabolites were present in the systemic circulation at any one time. This was further investigated by comparing the plasma levels of tritium with time and the tissue concentrations at 24 and 48 h after s.c. [3H]LAAM administration in biliary-cannulated and sham-operated control rats. Complete diversion of the bile did not significantly decrease the levels of [3H]LAAM or its metabolites in the systemic pool. These findings tend to minimize the contribution of enterohepatic circulation in the recirculation of active metabolites of LAAM and ultimately in its long duration of opiate-like action.

Animals↗
PubMed1979

The clinical analgesic efficacy of oral nefopam hydrochloride.

The analgesic efficacy of 60 and 120 mg nefopam hydrochloride was compared to 650 mg aspirin and placebo in a double-blind single-dose study. Oral doses were administered to 120 patients suffering from acute postsurgical or fracture pain. All active medications demonstrated analgesic activity in comparison to placebo. Patients on 120 mg nefopam obtained the greatest degree of analgesia. Side effects were minor and did not interfere with the course of therapy. The incidence of side effects (sweating, nausea, and lightheadedness) was greater on 120 mg nefopam than on 650 mg aspirin).

Adult↗