Effect of unit dose and route of administration on self-administration of morphine

1976 ◽  
Vol 50 (1) ◽  
pp. 103-105 ◽  
Author(s):  
Stanley G. Smith ◽  
Toreen E. Werner ◽  
W. Marvin Davis
Keyword(s):  
Route Of Administration ◽  
Self Administration ◽  
Unit Dose

scholarly journals Assessment of the Reinforcing Properties of Orally Administered MDMA ('Ecstasy') in Rats

2021 ◽  
Author(s):  
◽  
Lincoln S. Hely
Keyword(s):  
Oral Administration ◽  
Drugs Of Abuse ◽  
Demand Curve ◽  
Subcutaneous Administration ◽  
Route Of Administration ◽  
Schedules Of Reinforcement ◽  
Self Administration ◽  
Onset Of Action ◽  
Reinforcing Efficacy ◽  
Reinforcing Effects

<p>The so-called “party drug” 3,4-Methylenedioxymethamphetamine (MDMA, or ecstasy) may share many of the addictive properties common to other CNS stimulants. In humans MDMA is primarily consumed orally in one more pills per session. However, animal research has mostly focused on examining the effects of MDMA as a function of other routes of administration. Route of administration can have profound effects on the subjective and reinforcing properties of drugs of abuse. This thesis assessed the locomotor-activating and reinforcing properties of MDMA when delivered orally. MDMA-induced hyperlocomotion was used to examine magnitude of response and onset of action as a function of ip, sc and oral administration. Significant route-dependant effects were found with ip producing higher locomotor activity than sc and oral respectively. Onset of action was slower for subcutaneous administration compared with both ip and oral administration. The reinforcing properties of MDMA were examined by use of the self-administration procedure. Oral MDMA self-administration was firstly examined using simple schedules of reinforcement as a function of two different vehicle substrates, water (under water deprivation) and saccharin. Oral MDMA maintained responding and reliable dose-response curves were obtained under both water and saccharin vehicle conditions. However, both saccharin and water vehicle conditions also acted as strong reinforcers in these studies. Further studies utilising a behavioural economic approach were conducted in order to delineate the reinforcing effects of MDMA from that of its parent vehicle. In addition, demand-curve analysis using both the Linear-Elasticity model (Hursh et al., 1988, 1989) and the Exponential Model of Demand (Hursh & Silberberg, 2008) were compared in order to evaluate each model and assess the relative reinforcing efficacy of oral MDMA. Demand curves for the oral self-administration of MDMA revealed that responding for MDMA was more elastic (lower Pmax) than responding for saccharin-alone indicating that saccharin functioned as stronger reinforcer than did MDMA+saccharin. The results of these studies provide evidence for the positive-reinforcing effects of MDMA when it is delivered via the oral route of administration, however, the relative reinforcing efficacy of orally delivered MDMA appears to be low.</p>

scholarly journals Assessment of the Reinforcing Properties of Orally Administered MDMA ('Ecstasy') in Rats

2021 ◽  
Author(s):  
◽  
Lincoln S. Hely
Keyword(s):  
Oral Administration ◽  
Drugs Of Abuse ◽  
Demand Curve ◽  
Subcutaneous Administration ◽  
Route Of Administration ◽  
Schedules Of Reinforcement ◽  
Self Administration ◽  
Onset Of Action ◽  
Reinforcing Efficacy ◽  
Reinforcing Effects

<p>The so-called “party drug” 3,4-Methylenedioxymethamphetamine (MDMA, or ecstasy) may share many of the addictive properties common to other CNS stimulants. In humans MDMA is primarily consumed orally in one more pills per session. However, animal research has mostly focused on examining the effects of MDMA as a function of other routes of administration. Route of administration can have profound effects on the subjective and reinforcing properties of drugs of abuse. This thesis assessed the locomotor-activating and reinforcing properties of MDMA when delivered orally. MDMA-induced hyperlocomotion was used to examine magnitude of response and onset of action as a function of ip, sc and oral administration. Significant route-dependant effects were found with ip producing higher locomotor activity than sc and oral respectively. Onset of action was slower for subcutaneous administration compared with both ip and oral administration. The reinforcing properties of MDMA were examined by use of the self-administration procedure. Oral MDMA self-administration was firstly examined using simple schedules of reinforcement as a function of two different vehicle substrates, water (under water deprivation) and saccharin. Oral MDMA maintained responding and reliable dose-response curves were obtained under both water and saccharin vehicle conditions. However, both saccharin and water vehicle conditions also acted as strong reinforcers in these studies. Further studies utilising a behavioural economic approach were conducted in order to delineate the reinforcing effects of MDMA from that of its parent vehicle. In addition, demand-curve analysis using both the Linear-Elasticity model (Hursh et al., 1988, 1989) and the Exponential Model of Demand (Hursh & Silberberg, 2008) were compared in order to evaluate each model and assess the relative reinforcing efficacy of oral MDMA. Demand curves for the oral self-administration of MDMA revealed that responding for MDMA was more elastic (lower Pmax) than responding for saccharin-alone indicating that saccharin functioned as stronger reinforcer than did MDMA+saccharin. The results of these studies provide evidence for the positive-reinforcing effects of MDMA when it is delivered via the oral route of administration, however, the relative reinforcing efficacy of orally delivered MDMA appears to be low.</p>

Effects of response cost and unit dose on alcohol self-administration in moderate drinkers

1995 ◽  
Vol 6 (7) ◽  
pp. 754 ◽  
Author(s):  
M. L. Van Etten ◽  
ST. Higgins ◽  
W. K. Bickel
Keyword(s):  
Response Cost ◽  
Self Administration ◽  
Unit Dose

Discrete-trial control of cocaine self-injection behaviour in squirrel monkeys: effects of morphine, naloxone, and chlorpromazine

1977 ◽  
Vol 55 (4) ◽  
pp. 778-790 ◽  
Author(s):  
Roger Stretch
Keyword(s):  
Fixed Ratio ◽  
Relative Sensitivity ◽  
Suppressive Effect ◽  
Dependent Manner ◽  
Self Administration ◽  
Drug Reinforcement ◽  
Discrete Trials ◽  
Small Doses ◽  
Large Injection ◽  
Unit Dose

Intravenous cocaine self-injection behaviour was studied using a new discrete-trials procedure in monkeys. Daily sessions consisted of two sets of 40 discrete trials, separated by a 5-min time out (TO) period; the intertrial interval during each segment of the session was equal to 50 s. In the first experiment, cocaine self-injection behaviour (15 μg/kg per injection) was suppressed in a dose-dependent manner by morphine pretreatment (1–5.6 mg/kg, im). When cocaine self-injection responding was suppressed by morphine pretreatment (3 or 5.6 mg/kg, im), the morphine antagonist, naloxone (0.01–1.0 mg/kg, im), reinstated drug-taking behaviour; the effect depended upon the dose of the antagonist and upon the amount of morphine given to suppress cocaine self-administration behaviour. When monkeys were pretreated with chlorpromazine (0.03–5.6 mg/kg, im) before a cocaine self-injection session, small doses marginally increased responding and larger doses exerted a suppressive effect. These effects were observed when cocaine was available at a unit dose of 15 μg/kg per injection. When the unit dose of cocaine was increased to 300 μg/kg per injection, small doses of chlorpromazine (0.03–1 mg/kg, im) exerted no clearly detectable effects, though responding for drug injections was profoundly suppressed when sessions were preceded by chlorpromazine pretreatment at doses of 3 and 5.6 mg/kg, im. In this experiment, drug intake per session was greater when a large injection dose (300 μg/kg per injection) was available for self-administration than when a small dose (15 μg/kg per injection) could be self-injected; the frequency of drug self-injection was reduced, however, when the larger unit dose of cocaine replaced the smaller one. When considered in relation to the results of other experiments, it is evident that control of cocaine self-injection responding by a discrete-trials procedure results in schedule-dependent behaviours that differ in relative sensitivity to drug pretreatments from cocaine-reinforced responding controlled by fixed-ratio schedules of drug reinforcement.

scholarly journals Female rats self-administer heroin by vapor inhalation

2020 ◽  
Author(s):  
Arnold Gutierrez ◽  
Jacques D. Nguyen ◽  
Kevin M. Creehan ◽  
Michael A. Taffe
Keyword(s):  
The United States ◽  
Route Of Administration ◽  
Female Rats ◽  
Initial Increase ◽  
Prescription Opioids ◽  
Self Administration ◽  
Heroin Use ◽  
Male And Female Rats ◽  
Opioid Drugs ◽  
Withdrawal Signs

AbstractOver the last two decades the United States has experienced a significant increase in the medical and non-medical use of opioid drugs, resulting in record numbers of opioid-related overdoses and deaths. There was an initial increase in non-medical use of prescription opioids around 2002, followed later by increased heroin use and then most recently fentanyl. Inhalation is a common route of administration for opioids, with a documented history spanning back to Mediterranean antiquity and up through modern use with e-cigarette devices. Unfortunately, preclinical studies using inhalation as the route of administration remain relatively few. This study was conducted to determine the efficacy of e-cigarette vapor inhalation of heroin in rats. Non-contingent exposure to heroin or methadone vapor produced anti-nociceptive efficacy in male and female rats. Female rats were trained to self-administer heroin vapor; the most-preferring half of the distribution obtained more vapor reinforcers when the concentration of heroin was reduced in the vapor vehicle and when pre-treated with the opioid receptor antagonist naloxone. The anti-nociceptive effect of heroin self-administered by vapor was identical in magnitude to that produced by intravenous self-administration. Finally, anxiety-like behavior increased 24-48 hours after last heroin vapor access, consistent with withdrawal signs observed after intravenous self-administration. In sum, these studies show that rewarding and anti-nociceptive effects of heroin are produced in rats by vapor inhalation using e-cigarette technology. Importantly, self-administration models by this route can be deployed to determine health effects of inhaled heroin or other opioids.

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