Biomedical subjects

M L Stitzer

Publications and source records attributed to M L Stitzer.

At least 55 records · Page 3Linked to original sources

PubMed1996

Voucher-based reinforcement of attendance by unemployed methadone patients in a job skills training program.

This study evaluated the use of voucher reinforcement for maintaining attendance of unemployed methadone patients in a job skills training program. Participants received vouchers for attending daily 2-h computer data entry training sessions. The vouchers had monetary values and were exchangeable for goods and services. During the first 6-week condition, daily vouchers were initially worth $8, increased by $0.90 for every consecutive day of attendance to a maximum of $34.10, and reset to $8 following any day of missed attendance. During the second 6-week condition, voucher values decreased each day by 20% of that individuals' earnings on the previous day. During a final 4-week condition, the highest pay level previously achieved by each individual was reinstated and stayed at that level for the remainder of the condition, except that voucher values reset back to $8 following any missed session. Five of 7 participants completed the study. For those 5 participants, 94% and 98% attendance rates were sustained during first and second high pay conditions, respectively. Four of 5 subjects stopped attending when pay fell to $6-$9 (median = $7) per session in the descending pay amount condition (the fifth subject continued to attend throughout). Mean percent of work days attended was significantly higher during the two high pay conditions than during the decreasing pay condition (P < 0.001). All participants acquired data entry skills. Participants reliably rated the work experience as 'interesting', 'enjoyable', 'challenging', and 'helpful'. Mean ratings for these adjectives obtained on all days attended were significantly higher than ratings of the experience as 'frustrating', 'boring', or a 'waste of time' (P < 0.001). These data show that voucher-based reinforcement can promote sustained attendance of chronically unemployed substance abusers in intensive employment training programs and support the continued evaluation of these incentive procedures under a wider range of worksite training conditions.

Adult↗

PubMed1996

Concurrent validity of cocaine and sedative dependence diagnoses in opioid-dependent outpatients.

The present study evaluated the relationship between diagnoses of cocaine and sedative dependence and drug use early in treatment among opioid-dependent patients in methadone substitution therapy. New admissions (n = 138) were assessed via the Structured Clinical Interview for the DSM III-R (SCID) for presence of Axis I and Axis II disorders and followed for five weeks on standard methadone maintenance. Patients submitted urines three times per week tested for opioids, cocaine, and benzodiazepines. Patients diagnosed with current cocaine dependence (n = 90) submitted a higher proportion of cocaine-positive urines (M = 0.84) than patients diagnosed with past cocaine dependence (n = 32; M = 0.28) and those diagnosed with no cocaine use disorder (n = 14; M = 0.12), P < 0.001. Current cocaine dependence diagnosis accounted for 52% of the cocaine use variance. Patients exhibiting current sedative dependence (n = 25) submitted a higher proportion of benzodiazepine-positive urines (M = 0.60) than patients with past sedative dependence (n = 44; M = 0.20) and those with no sedative use disorder (n = 60; M = 0.05), P < 0.001. Current sedative dependence diagnosis accounted for 37% of the benzodiazepine use variance. Lifetime major depression (12%) and antisocial personality disorder (39%) were the most common nonsubstance use comorbid diagnoses. Axis I nonsubstance use disorder was associated with benzodiazepine use, while Axis II disorder was associated with both benzodiazepine and cocaine use early in treatment (P < 0.05). These data demonstrate the concurrent validity of DSM-III-R cocaine and benzodiazepine use diagnoses, and support the potentially important relationship between drug use and other psychiatric disorders.

Adult↗

PubMed1996

Buprenorphine versus methadone in the treatment of opioid dependence: self-reports, urinalysis, and addiction severity index.

This article reports results for patients who completed the 16-week maintenance phase of a double-blind clinical trial comparing buprenorphine (N = 43; average dose = 9.0 mg/day sublingually) with methadone (N = 43; average dose = 54 mg/day orally) in the outpatient treatment of opioid dependence. In addition to pharmacotherapy, treatment during the clinical trial included individual counseling, weekly group therapy, and on-site medical services. Patients in both medication groups showed significant and substantial improvements over time in areas of psychosocial functioning, as assessed by the Addiction Severity Index, rates of urinalysis tests positive for opioids, and self-reports of opioid withdrawal symptoms, illicit opioid use, and cocaine use. Buprenorphine and methadone produced very similar outcomes on the wide array of outcome measures assessed, and improvements for both groups were large and occurred rapidly after treatment entry. A trend toward continued improvement in opioid-positive urines over time was noted for the buprenorphine but not the methadone group. These results provide further evidence of the efficacy of buprenorphine in the treatment of opioid dependence and provide a characterization of the time course of effects for buprenorphine and methadone. In addition, these results demonstrate the benefits of drug abuse treatment, both for drug and alcohol use and in other areas of psychosocial functioning.

Adolescent↗

PubMed1996

Buprenorphine's physical dependence potential: antagonist-precipitated withdrawal in humans.

Buprenorphine is a partial mu opioid agonist with demonstrated efficacy in the treatment of opioid dependence. One potential advantage of buprenorphine over full mu opioid agonists is its reported low physical dependence profile. This study systematically examined physical dependence produced by maintenance with a clinically relevant dose of buprenorphine using antagonist challenge procedures. In this residential laboratory study, eight opioid-dependent volunteers maintained on 8 mg/day of sublingual buprenorphine were each challenged on independent occasions with placebo, i.m. naloxone (0.3, 1.0, 3.0 and 10.0 mg/70 kg) and p.o. naltrexone (0.3, 1.0 and 3.0 mg/70 kg) 14 hr after their daily buprenorphine dose using a repeated measures, cross-over design. Both naloxone and naltrexone precipitated time- and dose-dependent withdrawal, as evidenced by changes in subject-rated, observer-rated and physiological measures. Significant precipitated withdrawal occurred at 3.0 and 10 mg/70 kg i.m. of naloxone and 3.0 mg/70 kg p.o. of naltrexone. These results indicate that buprenorphine maintenance produces physical dependence and that i.m. naloxone and p.o. naltrexone produce equivalent effects in withdrawal precipitation under these conditions. Findings have implications for selection of antagonist doses for use in formulating combination agonist/antagonist medications and for use in transition of drug abusers from buprenorphine to antagonist maintenance therapies.

Adult↗

PubMed1996

Comparative clinical pharmacology of short-acting mu opioids in drug abusers.

The clinical pharmacology of fentanyl and alfentanil was examined in opioid-experienced volunteers with agonist and antagonist sensitivity measures. Two studies used within-subject, placebo-controlled, crossover designs. In study 1, fentanyl (0.125, 0.25 mg/70 kg i.v.) was followed at 0, 20, 60 and 180 min by naloxone (10 mg/70 kg i.m.). Agonist effects during 180-min and 0-min (control; simultaneous fentanyl-naloxone i.v. infusion) challenge sessions were compared. Fentanyl rapidly constricted pupils, depressed respiration and produced subjective "high" and opiate symptoms lasting 60 to 120 min, depending on the measure. Naloxone precipitated withdrawal symptoms of comparable intensity at each challenge point. In study 2, fentanyl (0.125, 0.25 mg/70 kg i.v.), alfentanil (1, 2 mg/70 kg i.v.) and saline were followed at 1 and 6 hr by naloxone (10 mg/70 kg i.m.). Agonist effects were examined during 6-hr challenge sessions. The two drugs produced a comparable range of effects with similar peak magnitude for 0.125 mg/70 kg fentanyl and 1 mg/70 kg alfentanil and for 0.25 mg/70 kg fentanyl and 2 mg/70 kg alfentanil. Alfentanil's duration of action was brief ( < 60 min). Withdrawal was precipitated at 6 hr only after 0.25 mg/70 kg fentanyl. These findings support typical mu opioid characteristics (pleasurable subjective effects, physical dependence) for both drugs, differential duration of action (fentanyl > alfentanil) and peak effects consistent with a 1:8 (fentanyl/alfentanil) potency ratio.

Adolescent↗

PubMed1996

Buprenorphine, morphine and naloxone effects during ascending morphine maintenance in humans.

One purpose of this study was to characterize the acute effects of the partial mu-opioid agonist buprenorphine administered to human subjects undergoing maintenance treatment with ascending doses of morphine. A second purpose was to examine the development of tolerance, cross-tolerance and physical dependence under the same morphine maintenance conditions. Six opioid-dependent volunteers were treated chronically with ascending morphine doses of 15, 30, 60 and 120 mg/day. Each morphine dosing level was maintained for 2 weeks, with test drugs administered during the second week of maintenance of each morphine dose. Both morphine (30 mg i.m.) and buprenorphine (6 mg i.m.) constricted pupils and produced reports of opioid-like subjective effects. The magnitude of these effects was inversely related to the morphine maintenance dose, with no effects being detected at higher maintenance levels. Naloxone (0.3 mg) produced little effect at lower morphine maintenance doses but precipitated withdrawal at higher maintenance doses. Buprenorphine failed to precipitate withdrawal even when subjects were treated with 120 mg/day morphine. These findings indicate that dose-dependent tolerance to morphine, cross-tolerance to buprenorphine and physical dependence develop during morphine maintenance. The finding that buprenorphine does not act as an antagonist under these dosing conditions further supports the clinical observation that there are conditions under which patients dependent on short-acting opioids can be comfortably transferred directly to buprenorphine maintenance treatment.

Adult↗

PubMed1995

Response to smoking as a function of prior smoking amounts.

Smoking patterns are changing to accommodate new environmental smoking restrictions. The current study explored the effects of prior smoking amounts on the behavioral, physiological, and subjective effects of smoking a single cigarette. Ten smokers (six females, four males) each participated in four laboratory sessions of 6 h duration. During each session, they smoked 0, 2, 5, or 11 cigarettes which were evenly spaced throughout the 6-h period at intervals ranging from 30 min (11 cigarettes) to 120 min (2 cigarettes), with condition order determined by a Latin square. At the end of each session, all smoked a final cigarette. Response to the last cigarette of the 6-h session was influenced by pretreatment smoking amounts. Number of puffs drawn from the cigarette (15.0, 14.1, 13.3, and 10.1) was inversely related to prior smoking density, as was heart rate increase (5.8, 4.0, 2.4, and 1.3 bpm). Three physical symptoms of smoking, dizzy, lightheaded and tingling, were significantly greater when preceded by 6 h of no smoking than when preceded by smoking at 30-min intervals. However, these symptoms were rated as mild (19-27 on a 100-point scale) even when no cigarettes had been smoked. These results suggest some dissipation of acute tolerance after 6 h of smoking abstinence. Liking and satisfaction ratings were inversely related to the pretreatment density of smoking. Liking scores for the last cigarette were 85, 71, 68 and 48 (on a 100-point analog scale) when 0, 2, 5 and 11 cigarettes had been smoked. Overall, the study showed that physiological and subjective effects of smoking are modulated by recent histories of smoking.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

Effects of buprenorphine and methadone in methadone-maintained subjects.

Buprenorphine, a partial mu opioid agonist, is an experimental medication under development for the treatment of opioid dependence as an alternative to methadone maintenance. The present study examined the relationship between level of opioid physical dependence and response to buprenorphine administration as part of a program to develop procedures for transferring patients from methadone to buprenorphine treatment. This laboratory study characterized the agonist and antagonist effects of acute doses of buprenorphine and methadone in subjects maintained on either 30 (n = 7) or 60 (n = 6) mg/day oral methadone. Test doses of placebo [sl. and PO), methadone (15, 30, and 60 mg PO) and buprenorphine (2, 4, and 8 mg sl.) were administered to volunteers residing on a closed residential unit. Subjective, physiological, observer-rated, and cognitive/psychomotor measures were collected for 6.5 h after test doses. Test doses of methadone, but not buprenorphine, constricted pupils and produced dose-related increases on subjective report measures reflecting opioid agonist drug effects. Agonist effects of methadone were more prominent in the 30 mg than in the 60 mg methadone maintenance condition. Buprenorphine, but not methadone, precipitated opioid withdrawal signs and symptoms that were more prominent in the 60 mg than in the 30 mg methadone maintenance condition. These findings suggest that abrupt transition from methadone to buprenorphine may produce patient discomfort that is positively related to both methadone maintenance dose and buprenorphine transition dose.

Administration, Oral↗

PubMed1995

Desire to smoke during spaced smoking intervals.

This study examined the detailed time course of desire to smoke self-reports during brief periods of tobacco smoking deprivation to determine how these reports are related to amount and spacing of scheduled smoking. During four independent sessions, subjects (n = 10) smoked cigarettes at 30-, 60-, or 120-min intervals, or only smoked a single cigarette at the end of the 6-h session. At 15-min intervals, subjects answered four analog scale questions measuring their desire to smoke which were averaged to produce a single score. Mean desire to smoke scores were 28, 43, 59 and 71 in the 30-, 60-, 120- and 360-min cigarette spacing conditions, respectively, indicating an orderly relationship with amount of scheduled smoking. Patterns of change were similar across repeated observations and during several different deprivation intervals. Desire to smoke ratings, although temporarily suppressed by smoking, began rising within minutes of smoking and increased to near maximum levels (about 80 on a 100-point scale) after fewer than 3 h of abstinence. The observed rapid escalation in desire to smoke ratings during brief periods of abstinence is consistent with cigarette craving being reported by regular smokers who are not trying to quit. Further, if cravings can be accepted as a feature of tobacco withdrawal, the results support the view that avoidance of withdrawal is an important factor that maintains regular cigarette smoking.

Adult↗

PubMed1995

Acute physical dependence: time course and relation to human plasma morphine concentrations.

OBJECTIVES: To characterize the postmorphine time course of precipitated withdrawal responses in comparison with the time course of opioid agonist effects and of plasma morphine concentrations. BACKGROUND: The study provides a more detailed and comprehensive assessment of the postagonist time course of acute dependence effects in humans than previously available. DESIGN: Opioid agonist effects, morphine plasma levels, and withdrawal effects precipitated by naloxone (10 mg/70 kg, administered intramuscularly) were examined at 1, 3, 6, 12, 18, 24, 30, 36, and 42 hours after a single dose of morphine (18 mg/70 kg, administered intramuscularly) in 10 nondependent opioid-experienced subjects. RESULTS: The intensity of subjectively reported precipitated withdrawal effects was greatest when testing was conducted at 6 hours after morphine administration, whereas peak intensity of agonist effects (pupil constriction and subjective ratings) and highest plasma morphine concentrations (57.3 ng/ml) were observed at the shortest test interval (1 hour) after morphine. Offset time course of naloxone-precipitated effects differed across specific measures, with hot and cold feelings elevated for the longest time after morphine (36 hrs), but significant effects were generally apparent for up to 24 hours after morphine pretreatment. Agonist effects lasted through only 12 hours; trace amounts of morphine were detected in plasma for up to 30 hours after administration. CONCLUSIONS: Results show that acute physical dependence engendered by a single dose of morphine peaks later and persists over a longer duration after morphine administration than do other agonist effects. This suggests that neuronal adaptations underlying physical dependence develop and decay gradually over time during a single episode of receptor occupancy. The presence of detectable morphine in plasma is consistent with a competitive displacement mechanism of precipitated effects, although noncompetitive actions of morphine or its metabolites are not ruled out.

Acute Disease↗

PubMed1995

Evaluating the reinforcement value of clinic-based privileges through a multiple choice procedure.

A novel multiple choice procedure was utilized to evaluate the potential reinforcement value of three clinic-based incentives available during routine methadone treatment: methadone take-homes, methadone dose increases, and extra counseling. Fourteen methadone maintenance patients who were not earning any of these incentives completed a multiple choice form in which they made choices between pairs of incentives and subsequently between each incentive and a series of monetary values. Choice behavior was intermittently reinforced by randomly awarding to patients one of their chosen preferences. Results demonstrated that take-homes were worth US$20.24 and were rated as more desirable than dose increases (US$13.89) and extra counseling (US$7.47). The study updates and extends past research in this area and provides a methodology for establishing both a monetary value for clinic-based incentives and an absolute magnitude between preferences. The procedure could be used to examine a larger number of potential reinforcers and to understand individual differences in responding to incentive-based treatment programs.

Adult↗

PubMed1995

A placebo controlled clinical trial of buprenorphine as a treatment for opioid dependence.

Large-scale placebo controlled clinical trials assessing the efficacy of medications for the treatment of drug dependence have generally been limited to alcohol, cocaine and nicotine dependent populations. The purpose of the present study was to assess the early (1-2 week) clinical effectiveness of buprenorphine versus placebo in an opioid dependent population. The study used a parallel-group design with a behavioral choice component to compare buprenorphine (a mu-opioid partial agonist) to placebo for the treatment of opioid dependence. Opioid dependent volunteer patients participated in a 14-day study to assess the effectiveness and patient acceptance of this new pharmacotherapy for the treatment of opioid dependence. Patients were randomly assigned to placebo (n = 60) or 2 mg (n = 60) or 8 mg (n = 30) daily sublingual buprenorphine. All doses were administered double-blind. On days 6-13 all patients could request a dose change, knowing that their new dose would be randomly chosen from the remaining 2 alternatives. Compared to placebo, patients given buprenorphine (independent of dose) showed greater time on initial dose, requested fewer dose changes, used less illicit opioids (assessed by urinalysis), and rated dose adequacy higher. These results demonstrate that a placebo controlled study with a behavioral choice component is an effective means of assessing the potential efficacy and acceptability of new pharmacotherapies for opioid dependence.

Administration, Sublingual↗

PubMed1995

Buprenorphine treatment of opioid dependence: clinical trial of daily versus alternate-day dosing.

Buprenorphine, a mu-opioid partial agonist, has demonstrated efficacy for the treatment of opioid dependence comparable to that of methadone. The clinical utility of buprenorphine would be enhanced if it could be dosed on a less than daily basis. The current study is a parallel-group outpatient clinical trial of daily versus alternate-day dosing with 8 mg sublingual (s.l.) buprenorphine. Participants were randomly assigned to daily (n = 51) or alternate-day (n = 48) schedules of active medication administration for an 11-week double-blind trial. Patients assigned to alternate-day buprenorphine received placebo every other day. Primary outcome measures were retention in treatment and urine specimens positive for opiates. Clinic attendance, dose adequacy ratings, withdrawal symptomatology, and urine specimens positive for cocaine were secondary outcome measures. Neither endpoint analysis with the intent-to-treat sample nor time course analysis with treatment completers revealed any statistically significant differences between the dosing schedules on any outcome measure. Examination of 95% confidence intervals suggested a non-significant trend for the daily dosing schedule to have superior clinical efficacy at the dose tested. Nevertheless, these results are generally consistent with previous studies of less than daily dosing with buprenorphine and support the conclusion that an alternate-day dosing schedule can be effective in and acceptable to a substantial portion of patients.

Adult↗

PubMed1995

Incongruity between occupational interests and academic skills in drug abusing women.

This study assessed the occupational interests and academic skills of 50 patients of a center for addiction and pregnancy. Patient ratings of 31 occupations showed that a subset of ten occupations (telephone operator, cosmetologist, mail clerk, data entry operator, child care worker, receptionist, office clerk, word processor, billing clerk, secretary) were of interest to significantly more subjects than other occupations (P < or = 0.05). Most of the desired occupations were office jobs requiring basic skills not possessed by most study participants. Although participants had completed a mean (range) of 11 (8-15) years of education, their mean (range) grade levels of reading, spelling and arithmetic were estimated at 6.9 (0.8-12), 6.8 (1-12), and 5.7 (2-11.8) years, respectively. These data suggest that the study participants will need basic skills training to achieve their occupational goals. Importantly, patient ratings also indicated that most participants were interested in receiving the needed training. Overall, the study suggests that provision of basic academic skills training may improve the long-term employment outcomes of these drug abusing women.

Achievement↗

PubMed1995

Acute administration of buprenorphine in humans: partial agonist and blockade effects.

Buprenorphine, a mixed opioid agonist-antagonist, is being investigated as a treatment for opioid dependence. This study compared the acute subjective and physiological effects of sublingual buprenorphine to those of p.o. methadone over a wide range of doses and compared the ability of both drugs to alter the effects of an opioid challenge. Male inpatient volunteers (n = 9) with histories of opioid abuse participated in this double-blind, double-dummy study. Sublingual buprenorphine (0, 0.5, 2, 8, 16 and 32 mg) and p.o. methadone (3.75, 15 and 60 mg) were administered once weekly according to a Latin-square design, and subjects were monitored on a variety of physiological and subjective measures. Twenty-four hours later, subjects were tested with ascending doses of i.m. hydromorphone (0, 1 and 4 mg) given 45 min apart. Buprenorphine and methadone produced typical opioid agonist effects of long duration, including pupillary constriction, respiratory depression and elevations on subject-rated and observer-rated indices of euphoria, sedation and opioid-like symptoms. The buprenorphine dose-effect curves were nonlinear and maximal effects for most physiological and subjective measures were observed between 4 and 8 mg, with no greater effects observed at higher doses. The methadone dose-effect curves were linear across the range of doses tested. High doses of buprenorphine and methadone both attenuated the response to hydromorphone challenge 24 hr later. These data indicate that there is a ceiling on the effects of buprenorphine in humans that may reduce its abuse liability and increase its safety, and indicate that opioid blockade occurs after acute administration of buprenorphine or methadone.

Adult↗

PubMed1995

Marijuana smoking: effects of varying puff volume and breathhold duration.

Two studies were conducted to quantify biological and behavioral effects resulting from exposure to controlled doses of marijuana smoke. In one study, puff volume (30, 60 and 90 ml) and in a second study, breathhold duration (0, 10 and 20 sec) were systematically varied while holding constant other smoking topography parameters (number of puffs = 10, interpuff interval = 60 sec and inhalation volume = 25% of vital capacity). Each study also varied levels of delta 9-tetrahydro-cannabinol marijuana cigarette content (1.75% and 3.55%). Regular marijuana users served as subjects (n = 7 in each experiment). Subjects smoked 10 puffs in each of six sessions; a seventh, nonsmoking session (all measures recorded at the same times as in active smoking sessions) served as a control. Variations in puff volume produced significant dose-related changes in postsmoking plasma delta 9-tetrahydro-cannabinol levels, carbon monoxide boost and subjective effects (e.g., "high"). In contrast, breathholding for 10 or 20 sec versus 0 sec increased plasma delta 9-tetrahydro-cannabinol levels but not CO boost or subjective effects. Task performance measures were not reliably influenced by marijuana smoke exposure within the dosing ranges examined. These findings confirm the utility of the controlled smoking technology, support the notion that cumulative puff volume systematically influences biological exposure and subjective effects, but cast doubt on the common belief that prolonged breathholding of marijuana smoke enhances classical subjective effects associated with its reinforcing value in humans.

Adult↗

PubMed1994

Opioid physical dependence development: effects of single versus repeated morphine pretreatments and of subjects' opioid exposure history.

In acute dependence, signs and symptoms of opioid withdrawal are precipitated when an opioid antagonist (naloxone) is administered following acute (e.g. single dose) pretreatment with a mu agonist. This study examined the influence of amount of previous opioid exposure, both immediate and remote, on intensity of precipitated withdrawal effects in an acute dependence model. Two groups of subjects, opioid abusers (n = 20) and nonabusers (n = 20), received either one 15 mg/70 kg IM morphine pretreatment or two such pretreatments spaced 24 h apart. Naloxone challenge (30 mg/70 kg) followed 4.33 h after the second pretreatment. There were clear effects of morphine pretreatment condition (single versus repeated 15 mg) on the intensity of precipitated withdrawal responses elicited by naloxone. More intense effects were seen after the repeated pretreatment, suggesting that physical dependence escalates with repeated opioid exposures spaced at appropriate intervals. Subjects with an opioid abuse history reported greater liking of agonist drug effects than did nonabusers, whereas nonabusers reported more sedating effects. However, an opioid abuse history did not influence the intensity of precipitated withdrawal symptoms and signs. The latter finding suggests that a previous opioid exposure history does not dramatically modulate initial stages of physical dependence development during subsequent opioid exposure episodes.

Adult↗

PubMed1994

Buprenorphine versus methadone in the treatment of opioid-dependent cocaine users.

This study compared the efficacy of buprenorphine to methadone for decreasing cocaine use in patients with combined opioid and cocaine use. Participants (n = 51) were enrolled in a 26-week treatment program and randomly assigned to either buprenorphine or methadone. Dosing was double-blind and double-dummy. Patients were stabilized on either 8 mg sublingual buprenorphine or 50 mg oral methadone, with dose increases given in response to continued illicit cocaine use or opioid use through week 16 of treatment. Maximum doses possible were 16 mg buprenorphine and 90 mg methadone. Average doses achieved were 11.2 mg buprenorphine and 66.6 mg methadone; 49% of the patients received the maximum doses possible. Urine samples were collected three times per week, and there was no significant difference in the rate of cocaine positive urines for the intent-to-treat sample (69% for buprenorphine versus 63% for methadone). For patients who remained in treatment through the flexible dosing period (n = 28), there were significant decreases in cocaine positive urines over time (P < 0.01), but no significant differences between groups or group x time effects. Buprenorphine and methadone were equally effective on measures of treatment retention, urine results for opioids, and compliance with attendance and counseling. These results demonstrate no selective efficacy of either buprenorphine or methadone in attenuating cocaine use in this population, but do provide further support for the equivalent efficacy of buprenorphine and methadone in the treatment of opioid dependence.

Adolescent↗