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Biomedical subjects

C P O'Brien

Publications and source records attributed to C P O'Brien.

At least 37 records · Page 2Linked to original sources
PubMed2000

Amantadine in the treatment of cocaine-dependent patients with severe withdrawal symptoms.

OBJECTIVE: The study examined the effectiveness of amantadine in reducing cocaine withdrawal symptoms and improving treatment outcome among cocaine-dependent patients in outpatient treatment. METHOD: Sixty-one cocaine-dependent subjects participated in a double-blind, placebo-controlled trial of amantadine. RESULTS: Among subjects with severe cocaine withdrawal symptoms at the start of treatment, those who received amantadine used significantly less cocaine during the trial than did subjects who received placebo. Compared to subjects who received placebo, subjects who received amantadine submitted significantly more benzoylecgonine-negative urine samples and used cocaine on significantly fewer days during the trial. CONCLUSIONS: Amantadine may be an effective treatment for cocaine-dependent patients with severe cocaine withdrawal symptoms.

Amantadine↗
PubMed2000

Improving naltrexone response: an intervention for medical practitioners to enhance medication compliance in alcohol dependent patients.

The effectiveness of naltrexone, a FDA-approved medication for alcohol dependence, can be improved if we support and help patients to consistently take their medication. We illustrate how patient noncompliance with treatment negatively affects outcome, and, we describe a new intervention to enhance medication compliance. Outcome was evaluated for 196 alcohol dependent outpatients who were treated with 50 mg/day naltrexone or placebo for 12 weeks. For patients who adhered to the prescribed treatment, relapse rates were lower with naltrexone than placebo (10% vs. 38.6%, p < 0.001). For noncompliant patients, relapse rates were high and comparable between naltrexone- and placebo-treated patients (42.9% vs. 40%). In a second study of 100 alcohol dependent outpatients, we introduced an intervention that resulted in better medication compliance rates compared to a previous naltrexone study of patients who did not receive the intervention (77.0% vs. 60.8%, p < 0.01). This provided some support for the use of an intervention that targets medication compliance when prescribing naltrexone.

Adult↗
PubMed2000

Alcohol and the athlete.

Alcohol and the athlete have been linked together since ancient times. It continues to be the most commonly consumed drug among the athletic population. Alcohol use carries significant potential adverse effects for both the health and welfare of the individual. It is suggested that alcohol related problems may be more prevalent in the athletic population due to their risk taking mentality and the age profile of athletes (18- to 24-year-old males). Alcohol consumption also appears to have a causative effect in sports related injury, with an injury incidence of 54.8% in drinkers compared with 23.5% in nondrinkers (p < 0.005). This may be due in part to the hangover effect of alcohol consumption, which has been shown to reduce athletic performance by 11.4%. Alcohol is a potentially lethal drug and is a banned substance for certain Olympic sports. Education is the cornerstone for appropriate social use of this drug. Athletes and coaches need to be aware of the sports related adverse effects of alcohol consumption and its role in sports injury and poor physiological performance. It is recommended that alcohol should be avoided by the serious athlete.

Adolescent↗
PubMed2000

6-beta-naltrexol reduces alcohol consumption in rats.

BACKGROUND: In humans, 6-beta-naltrexol is the major metabolite of naltrexone, and its effectiveness at suppressing alcohol consumption in any species has not been previously investigated. Naltrexone is an opiate antagonist that reduces excessive drinking in many species, including humans with alcohol dependence. Whether 6-beta-naltrexol is an active metabolite that contributes to the efficacy of naltrexone remains unknown. METHODS: Placebo and four doses of 6-beta-naltrexol were given by intraperitoneal injection to outbred Wistar rats and alcohol consumption was measured using a limited access model. RESULTS: 6-beta-Naltrexol reduced alcohol consumption in a dose-dependent manner. At doses 7.5, 12.5, and 25 mg/kg, 6-beta-naltrexol significantly decreased consumption of a 6% ethanol solution compared with saline control groups. CONCLUSIONS: These data suggest that there may be a potential clinical use for 6-beta-naltrexol in recovering alcoholics.

Alcohol Drinking↗
PubMed1999

Comparing levels of cocaine cue reactivity in male and female outpatients.

Thirty-eight female and 26 male cocaine-dependent outpatients were exposed to cocaine cues in a laboratory setting. Stimuli consisted of an audiotape of patients discussing cocaine use, a videotape of simulated cocaine preparation and use, and the handling of cocaine paraphernalia. Overall, the stimuli produced significant decreases in skin temperature and skin resistance, and significant increases in heart rate, self-reported drug states (high, craving, and withdrawal), and self-reported negative moods. Females were more likely to report increased craving in response to the cues than males, but there were no other gender differences in any of the responses. Levels of reactivity in females were comparable to the results of previous studies with all male samples. These results support the use of a constant set of cues in future treatment studies employing gender-balanced patient samples.

Adult↗
PubMed1999

Attenuation of the euphoric effects of cocaine by the dopamine D1/D5 antagonist ecopipam (SCH 39166)

BACKGROUND: The subjective and reinforcing effects of cocaine in humans are associated with the enhancement of endogenous dopamine function in the mesolimbic system. This study examined the role of dopamine D1-like receptors in the behavioral and mood effects of cocaine by evaluating the effects of the selective D1/D5 antagonist ecopipam (SCH 39166) on subjective responses to intravenous cocaine in 11 subjects with cocaine dependence as defined by DSM-IV. METHODS: Subjects were pretreated in a randomized double-blind fashion with either placebo or 10 mg, 25 mg, or 100 mg of ecopipam orally on 4 separate occasions. Two hours later a single intravenous injection of 30 mg of cocaine was administered. Subjective and cardiovascular responses were measured and blood samples for pharmacokinetic evaluation were obtained prior to cocaine dosing and at various times after dosing. RESULTS: The euphoric (P = .004) and stimulating (P = .03) effects of cocaine were attenuated in a dose-dependent manner by ecopipam, while ratings of desire to take cocaine were diminished (P = .02). Ecopipam in combination with cocaine was safe and well tolerated. CONCLUSION: These data indicate a potentially important role for D1-like receptors in the acute mood-altering and rewarding effects of cocaine in humans.

Adult↗
PubMed1999

The NMDA receptor partial agonist, 1-aminocyclopropanecarboxylic acid (ACPC), reduces ethanol consumption in the rat.

The present studies assessed the effects of both systemic and intraaccumbens injections of 1-aminocyclopropanecarboxylic acid (ACPC), and NMDA partial agonist, on ethanol consumption in a limited access procedure in Wistar rats. Systemically administered ACPC reduced ethanol consumption in a dose-dependent manner, while a single dose of ACPC administered bilaterally into the nucleus accumbens also reversibly reduced ethanol consumption. Indirect measures of general appetitive behavior showed no effect of ACPC on weight or water intake, which suggests that this effect of ACPC may be specific to ethanol. These data are compatible with the role of NMDA receptors in modulating ethanol consumption and provide the first data showing that ACPC can reduce ethanol consumption. ACPC has neuroprotective effects and does not show the psychotomimetic effects observed with NMDA receptor agents. Thus, ACPC may be helpful in future clinical studies designed to reduce alcohol use.

Alcohol Drinking↗
PubMed1999

The effects of naltrexone on alcohol and cocaine use in dually addicted patients.

Concurrent dependence on cocaine and alcohol is common among patients seeking addiction treatment. This study was undertaken to explore the effectiveness of naltrexone (150 mg) as a potential treatment for patients who are alcohol and cocaine dependent. Of 15 subjects enrolled in the 12-week, open medication trial, 7 subjects did not complete the study. Relapse to clinically significant drinking occurred in 7 subjects (47%). There was a reduction in the average daily amount of alcohol consumed from pretreatment to treatment (p < .001) and the percentage of days engaged in drinking behavior (p < .001). Similarly, there was a reduction in the average weekly amount spent on cocaine from pretreatment to treatment (p = .001) and the percentage of days using cocaine (p < .001). This preliminary study suggests that naltrexone (150 mg) may be tolerable in patients dependent upon alcohol and cocaine and may be effective in reducing both cocaine and alcohol use. The results of this study provide a rationale for a double-blind placebo-controlled study of the efficacy of naltrexone in this difficult to treat but prevalent population.

Adult↗
PubMed1999

Continuing care for cocaine dependence: comprehensive 2-year outcomes.

This report presents 2-year outcome data from an outpatient continuing care study in which cocaine-dependent patients (N = 132) were randomly assigned to either standard group counseling (STND) or individualized relapse prevention (RP). Data on cocaine outcomes during the 6-month treatment phase of the study were presented in an earlier report (J. R. McKay, A. I. Alterman, J. S. Cacciola, M. R. Rutherford, & C. P. O'Brien, 1997). In the present report, a continuing care condition main effect was obtained on only 1 of 8 outcome variables examined. However, patients who endorsed a goal of absolute abstinence on entering continuing care had better cocaine use outcomes in RP than in STND, whereas the opposite was the case for those with less stringent abstinence goals. In addition, patients with current cocaine or alcohol dependence on entering continuing care who received RP had better cocaine use outcomes in Months 1-6 and better alcohol use outcomes in Months 13-24 than those in STND.

Adult↗
PubMed1999

The disabling nature of comorbid depression among older DUI recipients.

Alcoholism and depression are two of the most common and disabling mental illnesses in late life. This study is a descriptive report of a sample of 49 adults who had recently been convicted of Driving Under the Influence of alcohol (DUI). A lifetime history of alcohol abuse or dependence was present in 48 subjects (98%), while a depressive disorder occurred in 24 (49%) of the subjects. Concurrent alcoholism and depression, present in 12 subjects (24.5%), produced greater self-reported disability compared to those subjects with alcoholism alone. One-year longitudinal follow-up was available on 31 subjects (63.3%). Over the course of one year, there were no changes in drinking behavior, depressive symptoms, or self-reported quality of life. These data support previous studies that suggest greater disability in patients with concurrent mental illnesses.

Adult↗
PubMed1999

Limbic activation during cue-induced cocaine craving.

OBJECTIVE: Since signals for cocaine induce limbic brain activation in animals and cocaine craving in humans, the objective of this study was to test whether limbic activation occurs during cue-induced craving in humans. METHOD: Using positron emission tomography, the researchers measured relative regional cerebral blood flow (CBF) in limbic and comparison brain regions of 14 detoxified male cocaine users and six cocaine-naive comparison subjects during exposure to both non-drug-related and cocaine-related videos and during resting baseline conditions. RESULTS: During the cocaine video, the cocaine users experienced craving and showed a pattern of increases in limbic (amygdala and anterior cingulate) CBF and decreases in basal ganglia CBF relative to their responses to the non-drug video. This pattern did not occur in the cocaine-naive comparison subjects, and the two groups did not differ in their responses in the comparison regions (i.e., the dorsolateral prefrontal cortex, cerebellum, thalamus, and visual cortex). CONCLUSIONS: These findings indicate that limbic activation is one component of cue-induced cocaine craving. Limbic activation may be similarly involved in appetitive craving for other drugs and for natural rewards.

Adult↗
PubMed1999

The frequency of caffeine withdrawal in a population-based survey and in a controlled, blinded pilot experiment.

Reports of symptoms when regular caffeine consumption is stopped have appeared in the medical literature, but the frequency and significance of this phenomenon have remained controversial. The objective of this study was to collect information on the prevalence and severity of caffeine withdrawal in the general population and determine the incidence and type of symptoms reported on blind abrupt and gradual caffeine cessation among coffee drinkers reporting past episodes of caffeine-withdrawal symptoms. A community-based telephone survey was followed by a stratified, randomized, double-blind controlled study. Participants included 11,112 persons spontaneously calling to inquire about studies not related to caffeine and 57 regular caffeine users selected from among the callers because of self-reported caffeine-withdrawal symptoms. Gradual or abrupt withdrawal from caffeine was compared to continuation of the same caffeine level. In a survey of 11,112 persons, 61% reported daily caffeine consumption, and 11% of the caffeine consumers reported symptoms upon stopping caffeine. Among the regular caffeine users, only 0.9% of males and 5.5% of females reported symptoms significant enough to interfere with normal activities when they abruptly stopped caffeine. A group of those reporting withdrawal symptoms were randomly assigned to three subsamples. In the group subjected to abrupt withdrawal (N = 18), 6 (33.3%) reported symptoms (e.g., headaches and tiredness). Including decreases in functional ratings, a total of 7 of the 18 (38.8%) could be considered to have experienced caffeine withdrawal. The gradual withdrawal group (N = 20) reported minimal if any caffeine withdrawal symptoms. A third group (N = 18) was kept on a level dose of caffeine for comparison. When participants are unaware of the caffeine-withdrawal focus of the study, these results suggest that both the frequency and severity of caffeine-withdrawal symptoms are much lower than found in some previous reports and that clinically significant symptoms may be uncommon events among the general population.

Adult↗
PubMed1999

Damage to the superior gluteal nerve after two different approaches to the hip.

We have carried out a blind, prospective study of 50 consecutive patients undergoing replacement arthroplasty of the hip using two different approaches. Clinical assessment, including the Harris hip score and a modified Trendelenberg test, and electrophysiological examination of the abductor muscles of the hip were undertaken before and three months after surgery. We found that 48% of patients had preoperative evidence of chronic injury to the superior gluteal nerve. Perioperative injury to the nerve occurred commonly with both approaches to the hip. We did not find a significant correlation between injury to the superior gluteal nerve and clinical problems.

Aged↗
PubMed1998

A comparison of the effects of the opioid antagonists naltrexone, naltrindole, and beta-funaltrexamine on ethanol consumption in the rat.

The effects of the universal opioid antagonist naltrexone were compared to the delta-selective opioid antagonist naltrindole and the mu-selective opioid antagonist beta-funaltrexamine on ethanol consumption in the absence of food or fluid deprivation using a limited access procedure in Wistar rats. Both naltrexone, at doses of 0.1, 0.25, 0.5, 1.0, 3.0, and 10 mg/kg, and beta-funaltrexamine, at doses of 5.0 and 20.0 mg/kg, significantly decreased consumption of a 6% ethanol solution compared to saline control groups. Naltrindole, at doses of 5.0 and 15.0 mg/kg, failed to significantly reduce ethanol consumption. In addition, the highest doses of naltrexone, which antagonize delta as well as mu-opioid receptors, did not differ significantly from the lowest doses in their ability to reduce ethanol consumption. These data suggest that ethanol consumption using the limited access paradigm in the outbred rat is modulated by mu rather than delta-opioid receptors. Although this is not consistent with other data showing that delta antagonists decrease ethanol consumption, it is suggested that these difference may be related to the alcohol-preferring rats used in those experiments.

Alcohol Drinking↗
PubMed1998

Random versus nonrandom assignment in the evaluation of treatment for cocaine abusers.

Cocaine-abusing patients randomly assigned to day-hospital or inpatient rehabilitation were compared with patients who self-selected these treatment settings to examine differences in substance use and psychosocial outcomes under experimental and nonexperimental designs. There was little evidence of setting or assignment effects or Setting x Assignment interactions over the 12-month follow-up period. However, Assignment x Time interactions were obtained with 2 measures of cocaine use and measures of family-social and psychiatric problem severity. These interactions indicated greater problem severity at intake among the randomized patients coupled with greater improvements by the 3-month follow-up relative to the nonrandomized patients. Findings suggest that randomized studies of treatment for cocaine abuse may produce somewhat larger estimates of improvement than what is observed in more typical treatment situations.

Adult↗
PubMed1998

Conditioning factors in drug abuse: can they explain compulsion?

There is a good deal of clinical evidence suggesting that compulsion to resume drug taking is an important part of the addiction syndrome. The symptoms comprising motivation to resume drug use, namely craving and compulsion, have been studied experimentally in human subjects. While much work remains to be done, there is evidence showing that these symptoms are influenced by learning. The research has been guided by animal studies demonstrating that drug effects can be conditioned. Much attention has been directed toward demonstrating the existence of drug conditioning in human addicts and exploring the neurological structures that may underlie such learned responses. We do not yet know the relative importance of learning in the overall phenomenon of relapse, and treatments based on conditioning principles are still under investigation.

Alcohols↗