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Biomedical subjects

P Chue

Publications and source records attributed to P Chue.

11 recordsLinked to original sources
PubMed2001

Paroxetine: a review.

Paroxetine is a potent and selective serotonin reuptake inhibitor (SSRI) with currently approved indications for the treatment of depression, obsessive-compulsive disorder, panic disorder and social phobia. It is also used in the treatment of generalized anxiety disorder, post traumatic stress disorder, premenstrual dysphoric disorder and chronic headache. Paroxetine, a phenylpiperidine derivative, is the most potent inhibitor of the reuptake of serotonin (5-hydroxytryptamine, 5-HT) of all the currently available antidepressants including the class of SSRIs. It is a very weak inhibitor of norepinephrine (NE) uptake but it is still more potent at this site than the other SSRIs. The selectivity of paroxetine, i.e., the ratio of inhibition of uptake of norepinephrine to serotonin (NE/5-HT) is amongst the highest of the SSRIs. Paroxetine has little affinity for catecholaminergic, dopaminergic or histaminergic systems and by comparison with tricyclic antidepressants (TCAs) has, therefore, a reduced propensity to cause central and autonomic side effects. Paroxetine exhibits some affinity for the muscarinic cholinergic receptor but much less than the TCAs. In addition, the adaptive changes of somatodendritic (5-HT(1A)) and terminal (5-HT(1B/1D)) autoreceptors observed with paroxetine are different to those observed with TCAs; it also inhibits nitric oxide synthase. It is both a substrate and an inhibitor of cytochrome isoenzyme P450 2D6. Paroxetine is well absorbed orally and undergoes extensive first pass metabolism that is partially saturable. Its metabolites are pharmacologically inactive in vivo. Steady state levels are achieved after 4-14 days and an elimination half-life of 21 h is consistent with once-daily dosing. There is wide inter-individual variation in the pharmacokinetics of paroxetine in adults as well as in the young and the elderly with higher plasma concentrations and slower elimination noted in the latter. Elimination is also reduced in severe renal and hepatic impairment. Serious adverse events are, however, extremely rare even in overdose. In summary, paroxetine is well tolerated and effective in the treatment of both depressive and anxiety disorders across the age range.

Animals↗
PubMed2001

Global assessment of functioning following assertive community treatment in Edmonton, Alberta: a longitudinal study.

OBJECTIVE: To examine longitudinally the effects of Assertive Community Treatment (ACT) on Global Assessment of Functioning (GAF) scores in Edmonton, Alberta. METHODS: We acquired GAF scores for all clients at initial registration in the ACT program and at subsequent 18- and 36-month time points while in ACT. We analyzed both the entire ACT cohort and separate diagnostic groups. RESULTS: We obtained baseline and follow-up GAF scores for 411 clients, of whom the largest diagnostic group suffered from schizophrenia (n = 189), followed by bipolar disorder (n = 98). Collapsed across all groups, GAF scores significantly improved at both 18 (P < 0.0001) and 36 months (P < 0.0001). By group, at 18-month follow-up, significant improvements were seen in patients with delusional disorder (P < 0.05), dysthymia (P < 0.05), schizoaffective disorder (P < 0.05), and schizophrenia (P < 0.001). This was also seen at 36-month follow-up, with the addition of significant improvements in those with bipolar disorder (P < 0.05). Those patients with major affective disorder or psychosis not otherwise specified (NOS) did not show significant improvements over time. Regardless of diagnosis, those clients with baseline GAF scores of < or = 40 significantly improved at both 18-month (P < 0.0001) and 36-month (P < 0.0001) follow-up, while those with baseline GAF scores above 40 did not show significant improvement. CONCLUSIONS: GAF scores improved at 18- and 36-month follow-up from enrolment in an ACT program. Groups with different diagnoses and levels of functioning at time of enrolment may not benefit to the same degree.

Activities of Daily Living↗
PubMed2001

Quetiapine and obsessive-compulsive symptoms (OCS): case report and review of atypical antipsychotic-induced OCS.

The atypical antipsychotics have advanced the treatment of schizophrenia and have proved to be effective agents in treating other disorders with or without psychotic features. We review the literature concerning an increasingly reported and interesting adverse effect, atypical antipsychotic-induced obsessive-compulsive symptoms (OCS). The first known report of quetiapine exacerbating OCS in a 43-year-old man with obsessive-compulsive disorder (OCD), trichotillomania, delusional disorder and bipolar II disorder is presented. Mechanisms, including 5-HT2A and 5-HT2C antagonism, serotonergic regulation of dopamine systems and putative dopaminergic subtypes of OCS and OCD, are discussed. Given the paradoxical efficacy of the atypical antipsychotics in pure OCD, the neurobiology and comorbidity of OCD and schizophrenia, as well as the increasing use of atypical antipsychotics, a cautious and rational pharmacotherapeutic treatment approach is recommended.

Adult↗
PubMed2000

Sulpiride for schizophrenia.

BACKGROUND: The antipsychotic drug sulpiride was formulated over 20 years ago and was marked as having a low incidence of adverse effects and an effect on the negative symptoms of schizophrenia. This relatively inexpensive antipsychotic drug has a similar neuropharmacological profile to several novel atypical drugs. OBJECTIVES: To estimate the clinical efficacy and tolerability of sulpiride. SEARCH STRATEGY: Electronic searches of Biological Abstracts (1982-1997), CINAHL (1982-1998), Cochrane Schizophrenia Group's Register (March 1998), Cochrane Library (Issue 1, 1998), EMBASE (1980-1998), MEDLINE (1966-1998), PsycLIT (1974-1997), SIGLE (1994-1998), and Sociofile (1974-1997) were supplemented by reference searching, contacting authors and the manufacturers of sulpiride. SELECTION CRITERIA: All randomised or quasi-randomised clinical trials focusing on the use of different doses of sulpiride or comparing sulpiride to (i) placebo; (ii) typical antipsychotic drugs; or (iii) atypical antipsychotic drugs, for those with schizophrenia or serious mental illness were selected. DATA COLLECTION AND ANALYSIS: Trials were reliably selected and quality rated. Data were independently extracted, by two reviewers (BGOS, MF), and analysed on an intention-to-treat basis. It was assumed that people who did not complete the follow up had no improvement. Authors of trials were contacted for additional and missing data. Relative risk (RR) and 95% confidence intervals (CI) of dichotomous data were calculated with the random effects model and weighted mean difference (WMD) was calculated for continuous data. MAIN RESULTS: The review currently includes 18 studies (30 citations). Studies are generally small and of poor quality. Limited evidence suggests that there is little difference between sulpiride and other drugs although the incidence of side effects may be less for sulpiride. There are no clear findings relating to negative symptoms. REVIEWER'S CONCLUSIONS: Sulpiride may be an effective antipsychotic drug but evidence is limited and data relating to claims for its value against negative symptoms is not trial-based.

Antipsychotic Agents↗
PubMed2000

Loxapine for schizophrenia.

BACKGROUND: Loxapine is a drug with D2/D3 receptor antagonist activity and a higher affinity for D3 than D2. Some authors have suggested that loxapine is more effective than typical antipsychotics in reducing the negative symptoms of schizophrenia, that extrapyramidal side-effects are not usually seen at clinically effective antipsychotic doses and that it should therefore be classed as atypical. OBJECTIVES: To determine the effects of loxapine compared with placebo, typical and other atypical antipsychotic drugs for schizophrenia and related psychoses. SEARCH STRATEGY: Electronic searches of Biological Abstracts (1980-1999), The Cochrane Library (Issue 1, 1999), The Cochrane Schizophrenia Group's Register (January 1999), EMBASE (1980-1999), MEDLINE (1966-1999), LILACS (1982-1996), PSYNDEX (1977-1995) and PsycLIT (1974-1999) were undertaken. In addition, pharmaceutical databases on the Dialog Corporation Datastar and Dialog services were searched. References of all identified studies were searched for further trials. Pharmaceutical companies and authors of trials were contacted. SELECTION CRITERIA: All randomised controlled clinical trials relevant to the care of schizophrenia that compared loxapine to other treatments. DATA COLLECTION AND ANALYSIS: Citations and, where possible, abstracts were independently inspected by reviewers, papers ordered, re-inspected and quality assessed. Data were independently extracted but excluded if loss to follow up was greater than 50%. For homogeneous dichotomous data the risk ratio (RR), 95% confidence interval (CI) and, where appropriate, the number needed to treat (NNT) were calculated on an intention-to-treat basis. For continuous data, weighted mean differences were calculated (WMD). All data were inspected for heterogeneity. MAIN RESULTS: Compared to placebo, loxapine is antipsychotic (Global effect - not improved at 6 weeks, n=66, RR 0.6 CI 0.4-0.9 NNT 4 CI 2-62) with similar adverse effect profile to typical drugs. Is as effective as typical drugs in the short term (4-12 weeks) (Global effect - not improved, n=411, RR 0.89 CI 0.7-1.2). Very limited heterogeneous data suggest that, given intramuscularly (IM), loxapine may be at least as sedating as IM haloperidol and thiothixene. REVIEWER'S CONCLUSIONS: Loxapine is antipsychotic but its effects are under researched. It is not clearly different from typical drugs in either its positive or adverse effects.

Antipsychotic Agents↗
PubMed2000

Sex differences in schizophrenia, a review of the literature.

OBJECTIVE: To comprehensively and critically review the literature on gender differences in schizophrenia. METHOD: An initial search of MEDLINE abstracts (1966-1999) was conducted using the terms sex or gender and schizophrenia, followed by systematic search of all relevant articles. RESULTS: Males have consistently an earlier onset, poorer premorbid functioning and different premorbid behavioral predictors. Males show more negative symptoms and cognitive deficits, with greater structural brain and neurophysiological abnormalities. Females display more affective symptoms, auditory hallucinations and persecutory delusions with more rapid and greater responsivity to antipsychotics in the premenopausal period but increased side effects. Course of illness is more favorable in females in the short- and middle-term, with less smoking and substance abuse. Families of males are more critical, and expressed emotion has a greater negative impact on males. There are no clear sex differences in family history, obstetric complications, minor physical anomalies and neurological soft signs. CONCLUSION: This review supports the presence of significant differences between schizophrenic males and females arising from the interplay of sex hormones, neurodevelopmental and psychosocial sex differences.

Age Distribution↗
PubMed2000

Antipsychotic agents and QT changes.

Recently, antipsychotic medications of the novel or atypical classes have received increased attention because of concerns with respect to potential lengthening of the QT interval, yet the currently available and commonly prescribed conventional antipsychotics are significantly more cardiotoxic, particularly agents in the butyrophenone and phenothiazine classes. Lengthening of the QT interval can be associated with a fatal paroxysmal ventricular arrhythmia known as torsades de pointes. The specific duration of the QT interval at which the risk of an adverse cardiac event is greatest, is not established. There is not only significant variation in the applied definition of an abnormal interval, but the maximal QT interval in healthy volunteers is greater than the currently accepted standards. The QT interval is influenced by normal physiological and pathologic factors, but the mechanisms remain unclear. Using recombinant technology, haloperidol and sertindole have been demonstrated to be high-affinity antagonists of a human cardiac potassium channel encoded by the human ether-a-go-go-related gene. Pimozide, however, has been shown to act principally through calcium channel antagonism, and chlorpromazine may affect sodium channels. Nevertheless, it is possible that these effects are significant only in the presence of predisposing factors, either genetic or acquired. Despite proven efficacy in clinical trials and subsequent supervised use in Europe, a number of recently developed antipsychotic medications are not available to patients in North America. Yet, conventional antipsychotic medications that would not be approved by current safety standards continue to be widely used.

Animals↗
PubMed1999

Hospital outcome measures following assertive community treatment in Edmonton, Alberta.

OBJECTIVE: To examine hospital outcome measures for individuals with chronic and severe mental illnesses before and after their registration in an assertive community treatment (ACT) program in Edmonton, Alberta. METHODS: Data were collected from Alberta Health on individuals who were registered in ACT from April 1993 to April 1995. For each individual, hospital outcome measures were calculated for the 365 days prior to and 365 days after registration for ACT (thus covering April 1, 1992-March 31, 1996). RESULTS: Data were collected from 295 individuals. Compared with 1 year prior to beginning ACT, there was a 34% reduction in hospital separations for patients with psychiatric diagnoses. The average length of stay (LOS) for each separated patient decreased by 56%, and the hospitalization days for each patient separated also decreased by 39%. The number of emergency visits for psychiatric reasons was reduced by 32%, and the number of clients visiting emergency departments for psychiatric reasons declined by 30%. CONCLUSIONS: In the 1-year period after registration in an ACT program, hospital outcome measures were improved in this cohort of 295 individuals with severe and chronic mental illnesses.

Adult↗
PubMedDate not supplied

Obsessive-compulsive disorder in schizophrenia.

OBJECTIVE: To examine the differences in demographic and clinical features of patients with schizophrenia, with or without comorbid obsessive-compulsive disorder (OCD). METHODS: Fifty-two subjects were recruited from clinical services in the city of Edmonton, Alberta and assessed for schizophrenia and OCD with structured clinical interviews and standardized clinical rating scales. RESULTS: The prevalence of OCD in individuals meeting criteria for schizophrenia was 25%. Those subjects having both schizophrenia and OCD scored significantly higher on the Y-BOCS, Hollingshead scale, and GAF; plus significantly lower PANSS negative symptoms and a trend in increased Parkinsonian symptoms compared with individuals with schizophrenia alone. CONCLUSION: Our preliminary findings indicate that patients with schizophrenia and OCD vary in selected demographic and clinical measures when compared to patients with schizophrenia alone. Patients with schizophrenia and OCD appear to have less negative symptoms, which may thus be reflected in the decreased GAF scores. It is speculated that patients with schizophrenia and OCD may have a greater propensity to basal ganglia dysfunction than those with schizophrenia alone resulting in increased Parkinsonian symptoms.

Adult↗