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Biomedical subjects

G M Simpson

Publications and source records attributed to G M Simpson.

At least 37 records · Page 2Linked to original sources
PubMed1997

The effects of clozapine on symptom clusters in treatment-refractory patients.

Preliminary results of a double-blind clozapine study in a population of chronic psychotic patients at a state psychiatric facility are reported. Thirty "treatment-refractory" schizophrenic patients given a diagnosis according to DSM-III-R criteria (mean age of 44 +/- 9.1 years and a duration of illness of 24.9 +/- 8.8 years) who received 300 mg or 600 mg of clozapine and randomized in a double-blind fashion were analyzed. Subjects were evaluated using the Brief Psychiatric Rating Scale (BPRS) and the Clinical Global Impression (CGI) Scale on a weekly basis for 16 weeks. Based on the changes in their CGI scores at week 16 of clozapine treatment, subjects were retrospectively categorized as "improvers" (N = 12) and "nonimprovers" (N = 18). The two groups were compared for changes in total BPRS and BPRS factor scores. In terms of total BPRS scores, we expected a difference between the two groups because they were categorized based on changes in their CGI scores. However, the total BPRS scores in improvers showed a significant decrease by week 6 of clozapine treatment. On analyzing the four BPRS factors, the improvers showed improvement in the thinking disturbance factor by week 1 that remained steady from week 7. On the hostility-suspiciousness factor, the improvers showed an improvement across time when compared with nonimprovers. The withdrawal-retardation factor showed improvement in both groups across time, whereas the anxiety-depression factor was least influenced by clozapine. These observations suggested that all BPRS symptom factors did not uniformly contribute to improvement in overall psychopathology, which was observed as a decrease in total BPRS scores.

Adult↗
PubMed1997

Extrapyramidal symptoms in patients treated with risperidone.

Data on extrapyramidal symptoms (EPS) from both arms of the North American multicenter comparative study of risperidone, placebo, and haloperidol were analyzed. The subjects were 523 patients with chronic schizophrenia who, after a 1-week washout period, received placebo, risperidone (2, 6, 10, or 16 mg/day), or haloperidol (20 mg/day) for 8 weeks; the trial was completed by 253 patients. Severity of EPS was assessed by means of the Extrapyramidal Symptom Rating Scale (ESRS). Mean changes (increases) in ESRS scores from baseline to worst score were significantly lower in each risperidone group than the haloperidol group on the total ESRS (parkinsonism + dystonia + dyskinesia), total parkinsonism, hypokinetic symptoms, and on the questionnaire (p < 0.001). On several of the subscales (dyskinesia, buccolinguomasticatory, and Clinical Global Impression severity of dyskinesia), mean change scores were significantly lower in some of the risperidone groups than in the placebo group (p < 0.05). At the clinically most effective risperidone dose (6 mg/day), the mean ESRS change score was not significantly different from that of the placebo group. A significant linear relationship was noted between mean change scores and increasing risperidone dose on 4 of the 12 ESRS subscales; nevertheless, even at 16 mg/day of risperidone, mean change scores were lower than in the haloperidol group. A linear relationship between increasing risperidone dose and use of antiparkinsonian medications was also apparent. Acute dystonic reactions occurred both in patients receiving risperidone and haloperidol. Patients with severe baseline EPS were at higher risk of EPS during the study than patients with low or moderate baseline EPS. It is concluded that low doses of risperidone cause few or no EPS and recommendations for initiation of risperidone treatment are made.

Adult↗
PubMed1997

Efficacy of lorazepam and haloperidol for rapid tranquilization in a psychiatric emergency room setting.

The efficacy of a benzodiazepine was compared with that of a neuroleptic for the rapid tranquilization of patients presenting at a psychiatric emergency room service. Thirty-seven highly agitated patients exhibiting psychotic symptoms were randomly assigned to receive either 2 mg lorazepam or 5 mg haloperidol as needed every 30 min for 4 h. Administration route was either intramuscular injection or oral concentrate. Symptom ratings were conducted each hour using double-blind procedures. Both medications reduced symptom ratings on the Brief Psychiatric Rating Scale and Global Clinical Impression of Overall Symptom Severity Scale. Global Clinical Impression scores for the two medication groups did not differ significantly either at baseline or at 4 h after entry into the study. However, Global Clinical Impression scores of patients in the lorazepam group were less severe at intermittent ratings. The groups did not differ on the Brief Psychiatric Rating Scale at any rating time. No differences were found either in the number of doses administered or in the administration route selected. Given the potential for severe extrapyramidal symptoms developing hours or days after a single dose of haloperidol, lorazepam may provide an excellent alternative for the rapid tranquilization of the acutely agitated psychotic patient in the emergency room setting.

Administration, Oral↗
PubMed1997

Clozapine withdrawal resulting in delirium with psychosis: a report of three cases.

BACKGROUND: Withdrawal symptoms for typical antipsychotics are generally mild, self-limited and do not include development of psychotic symptoms. In contrast, withdrawal symptoms for clozapine can be severe with rapid onset of agitation, abnormal movements, and psychotic symptoms. Different pathophysiologic etiologies have been suggested for these severe symptoms, including dopaminergic supersensitivity and rebound. METHOD: Three case reports of clozapine withdrawal symptoms are presented. A review of previous case reports and discussion of the etiology of withdrawal symptoms of typical antipsychotics and clozapine are provided. RESULTS: These three patients developed delirium with psychotic symptoms that resolved rapidly and completely upon resumption of low doses of clozapine. CONCLUSION: The severe agitation and psychotic symptoms after clozapine withdrawal in these three patients were due to delirium, perhaps the result of central cholinergic rebound. The withdrawal symptoms and delirium resolved rapidly with resumption of low doses of clozapine. Severe withdrawal symptoms can probably be avoided by slowly tapering clozapine and/or simultaneously substituting another psychotropic with high anticholinergic activity, such as thioridazine.

Adult↗
PubMed1996

Polydipsia and water intoxication in a long-term psychiatric hospital.

This cross-sectional survey attempts to establish the prevalence of polydipsia and water intoxication at a state hospital (N = 360) using staff diagnosis, specific gravity of the urine (SPGU), weight changes, and chart review. There were 150 [42%, 95% confidence interval (CI) 37-47%] patients diagnosed as polydipsic by the staff or by SPGU. At least 93 (26%, CI 21-30%) had primary polydipsia not explained by other causes. Chart review identified 17 (5%, CI 3-7%) patients with a history of water intoxication. Using a case-control study design, schizophrenia, extended duration of hospitalization, and heavy smoking were associated with primary polydipsia in a logistic regression analysis (respective odds ratios were 1.6, 1.8, and 3.6). All patients with a history of water intoxication were Caucasian (versus 83% in those without a history) and had significantly more extended hospitalizations (94 vs. 49%). Future case-control studies should combine longitudinal identification of true cases and controls and exhaustive collections of clinical information in a standardized way.

Adolescent↗
PubMed1996

Clozapine withdrawal effects and receptor profiles of typical and atypical neuroleptics.

Withdrawal effects of neuroleptics have not received much attention. Clozapine withdrawal phenomena have been attributed to psychosis arising from D2 supersensitivity, which is unlikely since it has minimal action on D2 receptors. The time course and clinical features of this phenomenon suggest that cholinergic overdrive and gamma-aminobutyric acid (GABA) supersensitivity occurs after withdrawal, since it is strongly anticholinergic and has a GABAergic action. Recently, a number of patients showed marked decompensation when they were switched from clozapine to risperidone, especially when they were rapidly tapered off clozapine. This was probably more due to withdrawal effects than the primary psychosis or a lack of efficacy of risperidone. A slow withdrawal schedule would facilitate homeostatic mechanisms; anticholinergics would be useful in clozapine withdrawal. This area has not received any attention from researchers, nor are there any guidelines for clinicians. This will be particularly important with the widespread use of atypical agents in the future.

Antipsychotic Agents↗
PubMed1996

Diurnal and weekly variation of tardive dyskinesia measured by digital image processing.

The diurnal and weekly variability of tardive dyskinesia (TD) was assessed instrumentally by digital image processing. Weekly assessments were obtained in ten patients over a 6-week period. In six of the ten patients, assessments were obtained four times over a single 12-h period. Results indicate that TD movements measured by instrumental assessment vary from week to week and throughout the day. Factors that appear to have affected the variability were changes in medications and the time of day when the assessments were conducted.

Adult↗
PubMed1995

Continuous infusion of clozapine increases mu and delta opioid receptors and proenkephalin mRNA in mouse brain.

The biochemical mechanisms involved in the actions of the atypical antipsychotic clozapine are still unclear. Because elevated levels of enkephalin in certain areas of the central nervous system may be necessary for antipsychotic activity, we have examined the effect of clozapine on certain receptors and mRNA transcripts involved in the opioid peptidergic system. Clozapine was infused continuously into mice for 21 days and the density of mu and delta opioid receptors was measured in the brains by quantitative receptor autoradiography, and the level of proenkephalin mRNA and dopamine D1 and D2 receptor mRNA were measured by in situ hybridization histochemistry. The results showed that continuous infusion of clozapine increased the density of D1 but not D2 receptors. However, it failed to alter the levels of either D1 or D2 dopamine receptor mRNA. By contrast, clozapine increased the density of mu and delta opioid receptors and increased the levels of proenkephalin mRNA. These results indicate that continuous treatment with clozapine increases opioid peptidergic activity in mouse brain and suggest that alteration of peptidergic activity as well as alteration of dopaminergic activity may be involved in its antipsychotic action.

Animals↗
PubMed1995

Oral tardive dyskinesia: validation of a measuring device using digital image processing.

The present study was performed to investigate the reliability and validity of a new device for the assessment of oral dyskinesias by means of digital image processing. Twenty schizophrenic patients with tardive dyskinesia (TD) and ten healthy controls were studied. In patients instrumental scores were compared to different clinical rating scale scores. Measurements were repeated after 2 weeks under the same circumstances to assess test-retest stability. Instrumental scores discriminated well between normal subjects and dyskinetic patients and correlated significantly with clinical ratings (r = 0.63). The test-retest correlations showed a correspondence not larger than 40%, detecting thus the fluctuation of the TD intensity over time. These results suggest that our device is a reliable and easy to handle technique for the assessment of TD. Furthermore, the ability of the device to analyze the frequency distribution of movements makes it a useful tool for the quantitative and qualitative analysis of TD.

Adult↗
PubMed1995

Treatment of polydipsia and hyponatremia in psychiatric patients. Can clozapine be a new option?

Polydipsia occurs frequently in chronic schizophrenic patients, some of whom develop intermittent hyponatremia. Most therapeutic efforts have tried to control the hyponatremia. Four schizophrenic patients, followed for more than one year, showed improvement on clozapine. Case 1 was an outpatient without history of hyponatremia who improved from polydipsia and psychosis. The last three were inpatients with polydipsia, intermittent hyponatremia, and psychosis who showed minimal improvement of psychosis but significant decrease in polydipsia and water intoxication. Case 2 relapsed to polydipsia when clozapine was discontinued on two occasions. Case 3 demonstrated polyuria during 39% of days before clozapine and in 0% of days after two weeks of clozapine. In case 4, most baseline sodium levels were abnormal, but all became normal after clozapine. A time-series analysis for intervention effects showed a significant effect of clozapine (p = .017). The limited information provided by these case reports suggest the need for controlled studies of the clozapine effect on polydipsic patients.

Adult↗