PubMed Health⌕ Search

Biomedical subjects

I Liebson

Publications and source records attributed to I Liebson.

At least 19 recordsLinked to original sources
PubMed1987

Phenylpropanolamine: effects on subjective and cardiovascular variables at recommended over-the-counter dose levels.

Two controlled clinical studies evaluated the effects of phenylpropanolamine HCL (PPA) on measures of blood pressure, pulse, and subjective state (mood). One hundred fifty subjects participated in a parallel groups design that compared a 75-mg sustained release (SR) preparation with a 25-mg tid. dosing regimen and placebo. Fifty-nine of these subjects participated in an additional cross-over component that compared SR PPA 75 mg with placebo. Measures of blood pressure, pulse, and subjective drug effect were obtained nine times throughout the course of a 12-hour session. Data analysis revealed no clinically and few statistically significant effects due to drug treatment. As expected, most measures showed circadian changes on both the cardiovascular and mood variables, which were not related to drug treatment. No euphorogenic or "amphetamine-like" effects were noted. Although further work is warranted regarding the effects of chronic or higher-than-normal doses of PPA, the current studies suggest that PPA, at currently recommended dose levels, is not associated with adverse effects on either cardiovascular or subjective functioning.

Adult↗
PubMed1978

Effects of d-amphetamine on speaking in isolated humans.

The effects of oral d-amphetamine, 5--20 mg were studied in isolated humans who produced speech monologues during experimental sessions. Drug effects were studied under double-blind conditions by making repeated observations within each subject after placebo or active drug. In the first experiment, d-amphetamine 15 mg was studied in 4 isolated subjects who had received instructions that they should talk some of the time during experimental sessions. All subjects spoke more after active drug than after placebo. In the second experiment, d-amphetamine 5--20 mg was studied in 4 subjects who were instructed to talk, but who also earned points under a fixed interval 5 min schedule by speaking (i.e. by closure of a voice operated relay). Point delivery did not generally influence patterns of speech over time. Reliable drug produced increases in amount of talking were observed in 3 of 4 subjects. Adjective checklist self report scores indicating a stimulant drug effect were also sensitive to effects of d-amphetamine. Under controlled laboratory conditions, an increase in speaking is a reliable behavioral effect of d-amphetamine in isolated humans producing speech monologues.

Adult↗
PubMed1977

Drug-produced changes in human social behavior: facilitation by d-amphetamine.

The effects of oral d-amphetamine 5-30 mg on human social and verbal behavior were studied using repeated observations within subjects under a time-sampling observation procedure in a residential research ward. d-Amphetamine increased socializing in all three subjects studied, but only increased standing in one of the subjects. In the second experiment throat microphones and voice-operated relays were used to measure automatically quantitative aspects of dyadic verbal interactions during 1-hr daily sessions. Total speaking time showed dose-related increases in 5 of the 7 subjects receiving d-amphetamine. Adjective checklist self-report scores indicating stimulant drug effects were as sensitive and reliable as the speaking measure to the effects of d-amphetamine in these subjects. Speaking time also increased in 2 of the 8 partners who received placebo when the subjects with whom they were paired received d-amphetamine. This represents a socially mediated indirect drug effect. Adjective checklist scores of the partners receiving placebo were not changed when the paired subjects received d-amphetamine. Under controlled experimental conditions the naturalistic human behaviors of socializing and speaking are sensitive dependent variables for behavioral pharmacology research.

Adult↗
PubMed1976

Facilitation of human tobacco self-administration by ethanol: a behavioral analysis.

The effect of ethanol on the cigarette smoking of alcoholic subjects was studied in a residential laboratory. During daily 6-hr sessions, cigarettes were obtained either by request to the ward staff or by operation of a lever (fixed-ratio 5 or 10). In a mixed sequence across days, sessions involved ingestion of either vehicle (orange juice or vehicle plus ethanol (133.7 g). During ethanol sessions, the rate of cigarette smoking increased from 26% to 117% of vehicle levels. A series of control studies eliminated a number of potential behavorial mechanisms for the observed effect and indicated that the ethanol-induced increase in cigarette smoking occurred under a variety of experimental conditions: (1) when smoking could not occur concurrently with ethanol or vehicle consumption; (2) when subjects were not allowed to socialize; (3) when ingestion of ethanol or vehicle was scheduled for a number of consecutive days; (4) when various doses of ethanol were administered under blind conditions. In control experiments, weighing unsmoked tobacco and counting the number of puffs per cigarette indicated the effect was not due to smoking less of each cigarette. The effect was not limited to the experimental sessions alone, since total daily smoking was higher on ethanol days than vehicle days.

Adult↗