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Biomedical subjects

S W Woods

Publications and source records attributed to S W Woods.

At least 19 recordsLinked to original sources
PubMed1998

Regional cerebral blood flow during acute and chronic abstinence from combined cocaine-alcohol abuse.

Regional cerebral blood flow (rCBF) was assessed using SPECT and HMPAO in ten cocaine abusers within 72 h of last cocaine use and then after 21 days of abstinence. In comparison to normals the cocaine abusers had significantly reduced rCBF in 11 of 14 brain regions with the largest reductions in the frontal and parietal cortex and greater rCBF in the brain stem. These perfusion defects appeared to be primarily due to combined alcohol and cocaine abuse and frontal but not parietal defects appeared to resolve partially during 21 days of abstinence.

Adult↗
PubMed1998

Hydromorphone-naloxone combinations in opioid-dependent humans under a naloxone novel-response discrimination procedure.

Naloxone-hydromorphone combinations were tested in participants trained to discriminate naloxone from placebo under a novel-response drug discrimination procedure while maintained on methadone. Naloxone alone produced dose-related increases in naloxone-appropriate responding, little or no "novel"-appropriate responding, and increases in opioid antagonist adjective ratings (n = 5). Hydromorphone alone produced dose-related increases in novel-appropriate responding, little or no naloxone-appropriate responding, and increases in opioid agonist adjective ratings (n = 6). When combined with naloxone, hydromorphone produced dose-related decreases in naloxone-appropriate responding and antagonist adjective ratings (n = 6). These findings are consistent with nonhuman data and suggest that this procedure may be useful as a human laboratory model of opioid withdrawal.

Adult↗
PubMed1998

Naltrexone augmentation of neuroleptics in schizophrenia.

This study was conducted to determine whether the addition of naltrexone to ongoing neuroleptic treatment would facilitate the reduction in positive or negative symptoms in patients with schizophrenia. Twenty-one patients meeting DSM-III criteria for schizophrenia were enrolled; all patients had been stabilized for at least 2 weeks on their dosage of neuroleptic medicine before entering the study. Patients were randomized to receive either placebo or naltrexone 200 mg/day for 3 weeks in addition to their neuroleptic. Patients randomized initially into the placebo arm were crossed over to receive naltrexone in a single-blind fashion for 3 additional weeks. All patients were rated weekly with the Brief Psychiatric Rating Scale (BPRS). Fifteen patients received placebo and six received naltrexone in the first 3 weeks. No significant effects of naltrexone on total BPRS scores or BPRS subscale scores were observed. Patients who received naltrexone on a single-blind basis at the end of the placebo-controlled trial demonstrated a transient exacerbation in negative symptoms as reflected by the total BPRS score and the BPRS Withdrawal-Retardation subscale score. Repeated-measures analysis of variance (ANOVA) on the BPRS total score of the subsequent treatment with naltrexone showed a trend for a significance in the drug by time effect. Repeated-measures ANOVA on the BPRS Withdrawal-Retardation subscale of the subsequent treatment with naltrexone showed a significant drug by time effect. The current data failed to indicate a clinical benefit when naltrexone was added to the neuroleptic regimen. Other potential applications of naltrexone in schizophrenia are addressed.

Adult↗
PubMed1998

Pretreatment attrition in a comparative treatment outcome study on panic disorder.

OBJECTIVE: Whereas the fact of attrition during the course of treatment is well documented, little is known about the factors that affect sample selection before the beginning of a study ("pretreatment attrition"). The present study reports on the degree and sources of pretreatment attrition at two sites of a multicenter study on panic disorder that compared treatment outcomes for imipramine and cognitive behavior therapy. METHOD: Data were collected at two clinical research sites, one with a pharmacological treatment orientation (N = 420) and one with a psychosocial treatment orientation (N = 208). RESULTS: The main source of pretreatment attrition was participant refusal. At both research sites, eligible patients most often refused participation because they were either unwilling to start treatment with imipramine (30.6% and 47.4%, respectively) or discontinue their current medication (22.6% and 35.1%, respectively). CONCLUSIONS: Results from comparative treatment outcome studies are limited not only to people who meet the study criteria but also to those who are willing to begin a medication treatment and discontinue their current medication.

Adolescent↗
PubMed1997

Multicenter collaborative panic disorder severity scale.

OBJECTIVE: To address the lack of a simple and standardized instrument to assess overall panic disorder severity, the authors developed a scale for the measurement of panic disorder severity. METHOD: Ten independent evaluators used the seven-item Panic Disorder Severity Scale to assess 186 patients with principal DSM-III-R diagnoses of panic disorder (with no or mild agoraphobia) who were participating in the Multicenter Collaborative Treatment Study of Panic Disorder. In addition, 89 of these patients were reevaluated with the same scale after short-term treatment. A subset of 24 patients underwent two independent assessments to establish interrater reliability. Internal consistency, convergent and discriminant validity, and sensitivity to change were also determined. RESULTS: The Panic Disorder Severity Scale was associated with excellent interrater reliability, moderate internal consistency, and favorable levels of validity and sensitivity to change. Individual items showed good convergent and discriminant validity. Analysis suggested a two-factor model fit the data best. CONCLUSIONS: The Panic Disorder Severity Scale is a simple, efficient way for clinicians to rate severity in patients with established diagnoses of panic disorder. However, further research with more diverse groups of panic disorder patients and with a broader range of convergent and discriminant validity measures is needed.

Agoraphobia↗
PubMed1997

Sustained-release methylphenidate for cognitive impairment in HIV-1-infected drug abusers: a pilot study.

Other investigators have reported clinical improvement from psychostimulant drugs in patients with HIV-1-related cognitive impairment. However, no previous research has substantiated this claim by using a controlled study design. We examined the efficacy of sustained-release methylphenidate (MSR) in a sample of substance abusers with HIV-1-related cognitive impairment. Eight HIV-1-infected methadone patients with impaired neuropsychological test performance participated in an inpatient double-blind placebo-controlled crossover trial of MSR 20-40 mg/day. On a composite neuropsychological measure, patients improved significantly from baseline during MSR but not placebo treatment. Nevertheless, MSR performance did not differ significantly from placebo performance. Patients appeared to improve as a function of time, regardless of sequence, with somewhat more improvement during MSR than placebo treatment.

Adult↗
PubMed1997

Cost-effectiveness of antidepressant treatment reassessed.

BACKGROUND: A recent simulation concluded that the serotonin-specific reuptake inhibitor (SSRI) paroxetine was more cost-effective than the tricyclic antidepressant (TCA) imipramine, despite substantially higher medication acquisition costs. METHOD: We replicated the previous model and revised key assumptions which drove the results. The revised model was subjected to sensitivity analysis. RESULTS: Most scenarios in the revised model showed that the TCA is equally or more cost-effective than the SSRI. Model revision producing these results were changes in assumptions about switched treatment success rates, treatment length and initial treatment success. The revised model appears sensitive to drug acquisition and delivery costs and costs of treatment failure. CONCLUSIONS: Based on the model, a policy of using TCAs as first-choice antidepressant treatment, with SSRIs reserved for those patients not doing well initially, appears more cost-effective than the reverse sequence. Given limitations in current knowledge about key parameters to include in a simulation model, large prospective random-assignment cost-effectiveness studies are needed.

Antidepressive Agents, Tricyclic↗
PubMed1997

Dose dependent effects of yohimbine on methadone maintained patients.

Twelve methadone-maintained patients were randomized into a controlled crossover study with active and placebo yohimbine 20 mg once a day (n = 4), 5mg three times a day (n = 4) or 10 mg three times a day (n = 4) for seven days to evaluate the effect of yohimbine on naloxone precipitated opiate withdrawal. The yohimbine dose of 10 mg TID was well tolerated and was associated with an average decrease of 30% in precipitated withdrawal symptoms.

Administration, Oral↗
PubMed1997

Chronic neuroleptic exposure in bipolar outpatients.

BACKGROUND: Although the chronic use of neuroleptic medications is generally discouraged in patients with bipolar disorder, data on the actual extent of this practice are relatively scarce. METHOD: All bipolar patients receiving treatment at the Connecticut Mental Health Center on September 1, 1994, were identified through a computerized administrative database; the medical record was then examined. Patients were included in the study if (1) the last two recorded diagnoses in the chart were concordant for bipolar disorder and (2) the patient had not been hospitalized in the past year. RESULTS: Of 49 patients meeting review criteria, 33 (67%) met criteria for chronic neuroleptic exposure. The mean +/- SD continuous neuroleptic dosage for these 33 outpatients was 416 +/- 527 mg/day chlorpromazine (CPZ) equivalents. The dosage distribution was skewed, with 17 (52%) receiving < or = 200 mg/day CPZ [corrected] equivalents. CONCLUSION: Chronic neuroleptic administration occurred frequently in our sample of nonhospitalized bipolar outpatients.

Adult↗
PubMed1996

Plasma levels of gamma-aminobutyric acid and panic disorder.

Low levels of gamma-aminobutyric acid (GABA) in plasma have been associated with the presence of mood disorders in patients with major depressive disorder. We examined plasma GABA in patients with panic disorder, a disorder that is often comorbid with major depression, and in a group of control subjects. Patients with panic disorder had plasma GABA levels that did not differ significantly from levels in controls subjects. These data support the specificity of low plasma GABA as a marker for mood disorders.

Adult↗
PubMed1996

A pilot study of dextromethorphan in naloxone-precipitated opiate withdrawal.

Dextromethorphan and its metabolite dextrophan antagonize N-methyl-D-aspartate (NMDA)-mediated activity in pre-clinical studies. We examined dextromethorphan's effects on naloxone-precipitated opiate withdrawal in opiate-dependent subjects stabilized on 25 mg of methadone. Subjects received challenges on three different days with 0.4 mg of intramuscular naloxone. Pretreatment 1 h before naloxone was with dextromethorphan in a double-blind, balanced, randomized design with either placebo, dextromethorphan 60 mg, or dextromethorphan 120 mg for six subjects; and placebo, dextromethorphan 120 mg, or dextromethorphan 240 mg for five subjects. There was considerable inter-individual variability in the response to dextromethorphan, but no net attenuation by dextromethorphan on any withdrawal measure assessed. Two of three subjects detoxified from methadone with dextromethorphan 60 mg orally every 4 h demonstrated considerable withdrawal.

Adult↗
PubMed1996

Acute cocaine effects on absolute cerebral blood flow.

Cocaine use has been associated with vasoconstriction and stroke, and several studies have demonstrated that it decreases relative cerebral blood flow (rCBF) in humans. However, rCBF has not been quantitated. We compared 40 mg IV cocaine hydrochloride to placebo effects on absolute rCBF in four cocaine users using 99mTc-HMPAO SPECT with a modified microsphere model for CBF quantitation. Cocaine produced significant decreases in rCBF in all regions studied with a mean decrease of 30% in absolute whole brain blood flow (P = 0.002) which was 3-fold greater than relative blood flow changes.

Adult↗
PubMed1996

The effect of gamma-hydroxybutyric acid on naloxone-precipitated opiate withdrawal.

Because gamma-hydroxybutyric acid (GHB), a GABA metabolite, attenuated spontaneous opiate withdrawal in a prior study, we studied GHB's effect on naloxone-precipitated opiate withdrawal. Eight opiate-dependent inpatients were stabilized on the opioid levorphanol, 18 mg daily. After an initial acclimatization challenge, subjects underwent three double-blind challenges on consecutive days. Pretreatment in a balanced randomization was with either placebo, GHB, 15 mg/kg, or GHB, 30 mg/kg, followed an hour later by intravenous naloxone, 0.4 mg/70 kg. GHB produced no significant attenuation of multiple withdrawal measures except for hot-cold feelings. GHB pretreatment slightly accelerated respiration prior to naloxone. Differences with prior studies may be due to (1) timing of GHB administration (giving postwithdrawal in prior studies), (2) direct reversal of GHB's anti-withdrawal effects by naloxone, or (3) differences between naloxone-precipitated and spontaneous opiate withdrawal.

Adult↗
PubMed1996

Effect of clonidine pretreatment on naloxone-precipitated opiate withdrawal.

The purpose of this pilot study was to validate a methodology for testing the opioid withdrawal-attenuating effects of new medications using clonidine as a positive control. Seven heroin-dependent subjects stabilized on levorphanol received naloxone challenge tests on 4 consecutive days in a 2 x 2 design with placebo or clonidine (0.4-0.5 mg) pretreatment, followed by 0.2 or 0.4 mg of i.v. naloxone. The change in the area-under-the-curve from the preclonidine base line for various measures of withdrawal was analyzed in a two-factor (naloxone dose and clonidine condition) analysis of variance. Clonidine significantly (P < .05) attenuated systolic and diastolic blood pressure, pulse, lacrimation, nasal congestion and plasma cortisol, but not subject-rated withdrawal severity. There was a robust dose-dependent adrenocorticotropic hormone response to naloxone that was not changed by clonidine pretreatment. The consistency between these results and prior studies of clonidine's antiwithdrawal efficacy suggests the validity of the methodology for testing medications to treat opiate withdrawal. Studies with larger samples are needed to refine this methodology.

Adrenocorticotropic Hormone↗
PubMed1995

Effects of tryptophan depletion on responses to yohimbine in healthy human subjects.

There is considerable evidence that both the norepinephrine (NE) and serotonin (5-HT) systems are involved in the regulation of human anxiety and fear responses. To assess the modulating effects of central 5-HT levels on NE function, 11 healthy human subjects were studied with placebo-controlled challenge tests involving tryptophan depletion followed by administration of the alpha-2-adrenergic antagonist yohimbine 0.4 mg/kg IV. Five of the 11 subjects reported a marked increase in feelings of nervousness (> or = 25 mm on a 100 mm analog scale) following the combination test, while 1/11 had this response to yohimbine alone. No subjects had an increase in nervousness during other control tests. The increase in nervousness after the tryptophan depletion-yohimbine test was statistically significant for the whole group, but there were no other unique changes in behavioral, physiologic or biochemical (MHPG, cortisol) variables with this test. These data are discussed in terms of possible functional interactions between the 5-HT and NE neurotransmitter systems.

Adrenergic alpha-Antagonists↗