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Biomedical subjects

R I Wang

Publications and source records attributed to R I Wang.

At least 55 records · Page 3Linked to original sources
PubMed1977

Detection of benzoylecgonine in human urine.

A thin-layer chromatography (TLC) method is described that can be used to detect benzoylecgonine (BE), a metabolite of cocaine, in human urine. It is a two-part procedure that can be integrated into a rapid screening program for drug abuse. The first part of the method utilizes two TLC solvent systems to identify a variety of drugs, including BE. The second part is specific for the cocaine metabolite and can be used as a confirmation method. The procedure is sensitive to 3-4 microgram/ml of BE in urine.

Chromatography, Thin Layer↗
PubMed1977

The safety and value of naloxone as a therapeutic aid.

The safety and value of naloxone as a therapeutic aid was demonstrated in a large population of narcotic dependent persons over a two-year period. Naloxone was used to precipitate the narcotic withdrawal syndrome. This withdrawal syndrome was rated according to a previously developed scale. Retrospectively, naloxone rating scores were correlated with the patients' initial dose of methadone. With patients who received 0.8 mg naloxone, good correlation was obtained between the naloxone test score and the optimum methadone dose (mg), as indicated by the patients' physical status during the initial three days of methadone treatment. Three hundred and sixty-three tests were administered to 343 persons and no individuals developed any serious effects such as convulsions, syncope or cardiovascular collapse.

Adolescent↗
PubMed1977

Determining optimum dose and acute tolerance of triazolam.

The present two-phase study was designed to determine the optimum hynotic dose of triazolam and to assess any evidence of acute tolerance. Subjective and objective data were used to assess hypnotic efficacy. In the dose-titration phase, the dose of triazolam was increased in 0-5 mg increments to the highest level tolerated by each individual patient. Maximum tolerable doses ranged between 0-5 and 3-0 mg; however, all subjects experienced maximum therapeutic effect at 1-5 mg triazolam. During the 4-night acute tolerance portion of the study no clear evidence of tolerance was found.

Adult↗
PubMed1976

Hypnotic efficacy of lorazepam and flurazepam.

In a double-blind crossover study involving 15 insomniac subjects, the hypnotic efficacy of lorazepam, 2 and 4 mg, was compared with flurazepam, 15 and 30 mg, and placebo. Five subjective measures were used: onset, length, and depth of sleep, number of times awakened, and satisfaction with the hypnotic. Lorazepam in 2- and 4-mg doses was comparable in hypnotic efficacy to flurazepam, 30 mg, according to most parameters of measurement. Side effects were minor, although relatively numerous at the 4-mg doses.

Anti-Anxiety Agents↗
PubMed1976

Characteristics of drug abuse patients at a Veterans Administration Hospital.

A total of 308 patients were treated at the Wood VAC Drug Treatment Center during its first 2 years of operation (November 1, 1971-October 318 1973). They completed confidential questionnaires upon admission. Personal information and data concerning drug usage were obtained. Significant findings include the following: 1. A wide variety of opiate and nonopiate drugs were available in the military. 2. Although most patients had experienced illicit drugs prior to service, over 60% tried heroin for the first time while in the military; 83% of these men were subsequently treated for opiate dependence. 3. High rates of unemployment, marital instability, and convictions for illegal activities were revealed. A significant proportion of first convictions occurred prior to major drug usage. Data suggest that a flexible and multimodal approach to drug abuse therapy may have the best potential for success. Problems in evaluating and coordinating drug treatment programs are discussed briefly.

Adult↗
PubMed1976

Effects of desipramine treatment on the biliary, fecal and urinary excretion of methadone in the rat.

The effects of desipramine (DMI) given i.p. 1 hour before administration of 14C-methadone (5 mg/kg s.c.) on the excretion of methadone in bile, feces and urine were studied. Rats with cannulated bile ducts excreted 52% of administered 14C into bile within 4 hours, 60% of the excretion as 2-ethylidine-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 30% as water-soluble metabolite (WSM). The percentages of 14C excreted within 48 hours into the feces and urine of rats without biliary fistula were 60.6 and 17.4%, respectively. The excretion of 14C in feces consisted mostly of EDDP. Urinary excretion consisted of unchanged methadone, EDDP and WSM in the first 12 hours and consisted mostly of WSM thereafter. DMI treatment increased biliary flow but decreased the biliary excretion of 14C, mainly by a decrease in WSM. The fecal output was greatly decreased by DMI, thus decreasing fecal excretion of 14C in the first 12 hours. DMI treatment markedly decreased urinary volume but did not change the urine pH. The decreased urinary excretion of WSM in DMI-treated rats during the first 12-hour urine sample accounted for most of the decreased elimination of 14C. It is suggested that DMI-induced inhibition of methadone metabolism in the liver is a major factor responsible for the observed decreases in the biliary and urinary excretion of WSM...

Animals↗
PubMed1976

Radioimmunuassay compared to thin-layer and gas--liquid chromatography for detecting methadone in human urine.

Radioimmunoassay was compared to thin-layer and gas--liquid chromatographic methods for detection of methadone in the urine of patients undergoing methadone maintenance therapy as treatment of heroin abuse. With urine samples known to contain methadone, 84% were positive by thin-layer chromatography as compared to 99% positives by the other two methods. This difference is attributed to the difference in sensitivity of the three methods. All three methods gave consistently positive results with urine samples from patients receiving 25 mg of methadone per day or more. With smaller daily doses the percentage of positive results obtained with thin-layer chromatography decreased. Analysis of urine samples not containing methadone showed no incidence of cross reaction of other drugs with the methadone radioimmunoassay. The methadone radioimmunoassay appears to be both sensitive and reliable; however, certain other factors limit its use as a primary screening method.

Chromatography, Gas↗
PubMed1976

Role of metabolism in the biliary excretion of methadone metabolites.

The biliary excretion of the major methadone metabolites was studied after the administration of purified 14C-labeled metabolites of methadone. The three methadone metabolites administered to rats were the pyrrolidine and pyrroline metabolites and the glucuronide conjugate of the hydroxylated pyrroline metabolite. We found that the excretion of 14C into bile was greater after administration of the metabolites which underwent fewer metabolic steps prior to biliary excretion. Phenobarbital pretreatment of rats increased the biliary excretion of 14C after the administration of the 14C-labeled pyrrolidine and pyrroline metabolites, both of which undergo further metabolism. Phenobarbital pretreatment did not change the biliary excretion of 14C-labeled glucuronide of the pyrroline metabolite which does not undergo further metabolism in the liver. Analysis of bile samples showed that the increased biliary excretion of 14C in phenobarbital-pretreated rats after administration of the labeled pyrrolidine and pyrroline metabolites was due primarily to increases in the biliary excretion of methadone metabolites which resulted from further in vivo metabolism of the injected metabolites. These data confirm our earlier suggestion (Roerig et al., Biochem. Pharmacol. 24: 355-362, 1975) that phenobarbital pretreatment increases biliary excretion of methadone metabolites by increasing hepatic metabolism of methadone. Furthermore, it can be concluded from these studies that metabolism is a rate-limiting process in the excretion of methadone metabolites in bile.

Animals↗
PubMed1975

Methods of identification and confirmation of abusive drugs in human urine.

A thin-layer chromatography (TLC) procedure is described to be used as the initial drug detection method for urine surveillance in a drug abuse treatment program. While the TLC method is sufficiently sensitive, it is prone to false-positive results. For this reason, two other drug detection methods (gas-liquid chromatography and radioimmunoassay) have been incorporated to confirm positive results obtained with TLC. The combined methodologies result in a urine surveillance procedure that is versatile, sensitive and highly reliable.

Amphetamine↗