The role of weight gain in explaining the effects of antipsychotic drugs on positive and negative symptoms: An analysis of the CATIE schizophrenia trial

Second-generation antipsychotics are associated with moderate benefits in terms of improved schizophrenia symptoms, but also with higher rates of side-effects such as excessive weight gain (WG); a consensus on their efficacy has not been reached. To date, no study has evaluated the interplay of treatments and side-effects in a single framework, which is a critical step to clarify the role of side-effects in explaining the efficacy of these antipsychotics. We used recent methods for mediation and interaction to clarify the role of WG in explaining the effects of second-generation drugs on schizophrenia symptoms. We used data from 1460 participants in the CATIE trial, assigned to either perphenazine (first-generation comparison drug), olanzapine, quetiapine, risperidone, or ziprasidone. The primary outcome was an individual's score on the Positive and Negative Syndrome Scale (PANSS) for symptoms of schizophrenia after 9 months, separately evaluated as positive (PANSS+), negative (PANSS-), and total PANSS score. WG after 6 months was investigated as a potential mediator and effect modifier. Results showed that, by limiting WG, patients would benefit of a considerably better improvement in terms of PANSS symptoms. In the scenario of weight change being controlled between -2% and 1% for all participants, patients assigned to olanzapine would experience the highest significant improvements in both PANSS+ (-2.66 points; 95% CI: -4.98, -0.35), PANSS- (-1.59; 95% CI: -4.31, 1.14), and total PANSS (-6.11; 95% CI: -13.13, 0.92). In conclusion, occurrence of excessive WG hampers the potentially beneficial effects of second-generation antipsychotics, thus suggesting future directions for treatment and interventions.

The role of PANSS symptoms and adverse events in explaining the effects of paliperidone on social functioning: a causal mediation analysis approach

To date, no study has evaluated the joint role of symptoms and adverse events as mediators of the effect of second-generation antipsychotics on patients' social functioning. We used recently developed methods for mediation analysis with multiple mediators to clarify the interplay of adverse events and symptoms in explaining the effects of paliperidone (R code for implementing the mediation analysis for multiple mediators is provided). We used data from 490 participants in a 6-week randomized dose-response trial that assigned three fixed dosages of ER OROS paliperidone (3, 9, and 15 mg/day). The primary outcome was an individual's score on the social performance scale assessed after 6 weeks. The sum of Positive and Negative Syndrome Scale (PANSS), weight gain, and extrapyramidal symptoms measured via the Simpson-Angus Scale after 5 weeks were investigated as potential mediators and effect modifiers of treatment effects. Results from mediation analyses showed that the improvements in social functioning are partly explained by reduction in PANSS symptoms. Suggestive evidence that adverse events could play a role as mediators was found. In particular, weight gain displayed a non-linear relationship with social functioning, whereby beneficial effects observed at small levels of weight gain were reduced in the presence of excessive weight gain. In conclusion, we found that the short-term effects of paliperidone on social functioning were dependent on the successful reduction in PANSS symptoms and possibly the occurrence of excessive weight gain, thus suggesting future directions for treatment and interventions.

Metabolic syndrome in psychiatrically hospitalized patients treated with antipsychotics and other psychotropics

OBJECTIVE

We evaluated prevalence and risk factors for metabolic syndrome in inpatients treated with antipsychotics, with or without other psychotropic drugs. Although the literature on metabolic syndrome in psychiatry has expanded in recent years, we seek to elucidate some of the remaining gaps by examining a severely and chronically ill population heavily treated with pharmacological agents.

METHODS

With data from medical records of 589 adults hospitalized at McLean Hospital in 2010 and 2011, we used standard statistical analyses to characterize risks and covariates of metabolic syndrome.

RESULTS

With prior antipsychotic treatment, prevalence of metabolic syndrome was 29.5%. The syndrome was strongly associated with being overweight (≥25 kg/m(2) in 60.1% of subjects), older age, longer treatment-exposure, schizoaffective diagnosis (39.8%), more illness-episodes or hospitalizations, polytherapy, and higher total daily chlorpromazine-equivalent doses, but not sex. Notably, metabolic syndrome risk was greater among young, antipsychotic treated patients (15.5-fold at age ≤25 years).

CONCLUSIONS

The findings extend information on the association of metabolic syndrome with antipsychotic treatment. Metabolic syndrome was found in 30% of antipsychotic-exposed inpatients. Risk was surprisingly high in young persons and after brief treatment-exposure, and psychotropic polytherapy increased risk.

Pilot randomized, controlled trial of pramipexole to augment antipsychotic treatment

The preferential dopamine D(3)-agonist pramipexole (4.25±0.38 mg/day) or placebo were added for up to 12 weeks to ongoing antipsychotic treatment for 24 adult patients with DSM-IV schizophrenia or schizoaffective disorder. Pramipexole was generally well-tolerated (82% trial-completion), and yielded greater decreases in PANSS-total scores (drug/placebo=2.1; p=0.04), with similar decreases in PANSS positive and negative scores and 6.7-fold greater reduction of serum prolactin concentrations compared to placebo. There were no differences in ratings of mood, cognition or extrapyramidal symptoms, all of which were low at intake.

Characteristics and clinical changes during hospitalization in bipolar and psychotic disorder patients with versus without substance-use disorders

BACKGROUND

Co-morbid substance-use disorders (SUDs) are prevalent among patients with severe psychiatric disorders, but the characteristics of such patients remain incompletely defined, and their current treatments and responses, poorly documented.

METHODS

We evaluated the records of 481 consecutive inpatients diagnosed with DSM-IV bipolar or schizoaffective disorders, or schizophrenia, admitted to McLean Hospital in 2004 or 2009. Demographic and clinical characteristics, and treatments, were extracted from hospital and pharmacy records for bivariate and multivariate analyses.

RESULTS

SUD prevalence increased 1.84-times from 2004 (31.3%) to 2009 (57.6%). Patients with (n=204) versus without co-morbid SUDs (n=277) were similar in many respects, but in multivariate modeling, the following factors were more likely with SUD, in rank-order: co-morbid anxiety disorders > men more than women > greater prevalence in 2009 vs. 2004 > younger age > greater doses of mood-stabilizers > shorter hospitalization.

CONCLUSIONS

Hospitalized patients with severe primary psychiatric disorders, and comorbid SUD were more likely to be young and have anxiety disorders, to receive more combinations and higher doses of mood-stabilizers, and show more improvement in impulsivity and hostility, but otherwise differed little in treatment-responses. Prevalence of SUD rose substantially in the past five years, with increased but largely unproved use of mood-stabilizers.

Changes in medication practices for hospitalized psychiatric patients: 2009 versus 2004

BACKGROUND

We tested the hypothesis that combinations and total daily doses of psychotropics for hospitalized patients diagnosed with major psychiatric disorders are rising.

METHODS

We evaluated McLean Hospital records of 481 consecutive inpatients with DSM-IV schizophrenia, schizoaffective, or bipolar disorders in 2004 (n = 278) or 2009 (n = 203) to compare characteristics and treatments.

RESULTS

In 2009, Clinical Global Impression (CGI)-severity scores were 6% lower at intake and improved 1.7 times more than in 2004, as hospitalization-length decreased by 12%. Polytherapy (> or = 2 psychotropics) increased in 2009 (affective or schizoaffective disorders > schizophrenia). Total psychotropics/patient (3.1-3.2) remained stable but mood-stabilizers/patient increased markedly and antipsychotics/patient decreased somewhat in 2009. Antipsychotic-choice (2009) ranked: quetiapine, aripiprazole, risperidone, and others; mood-stabilizers ranked: lamotrigine, valproate, lithium, and others (1/4 off-label). In 2009, final total antipsychotic doses (mg/day) increased by 97%, and mood-stabilizers by 75%. Adverse-effect rates fell by half. Factors differing independently for 2009 versus 2004 ranked: (a) more CGI improvement, (b) more mood-stabilizers/patient, (c) lower admission CGI scores, and (c) higher total antipsychotic dose.

COMMENT

Combinations and doses of antipsychotic and mood-stabilizing drugs for inpatients increased markedly (2004 vs. 2009) without consistent correspondence of agents/person and doses, without apparent increase in major adverse effects, and with possibly superior clinical improvement.

Comparison of mania patients suitable for treatment trials versus clinical treatment

It remains uncertain whether bipolar disorder (BPD) patients in randomized-controlled trials (RCTs) are sufficiently representative of clinically encountered patients as to guide clinical-therapeutic practice. We complied inclusion/exclusion criteria by frequency from reports of 21 RCTs for mania, and applied them in a pilot study of patients hospitalized for DSM-IV BPD manic/mixed states to compare characteristics and clinical responses of patients who did versus did not meet exclusion criteria. From 27 initially identified inclusion/exclusion criteria ranked by citation frequency, we derived six inclusion, and 10 non-redundant-exclusion factors. Of 67 consecutive patients meeting inclusion criteria, 15 (22.4%) potential "research subjects" met all 10 exclusion criteria. The remaining 52 "clinical patients" differed markedly on exclusion criteria, including more psychiatric co-morbidity, substance abuse, involuntary hospitalization, and suicide attempts or violence, but were otherwise similar. In both groups responses to clinically determined inpatient treatments were similar, including improvement in mania ratings. Based on applying reported inclusion/exclusion criteria for RCTs to a pilot sample of hospitalized-manic patients, those likely to be included in modern RCTs were similar to patients who would be excluded, most notably in short-term antimanic-treatment responses. The findings encourage further comparisons of subjects included/excluded from RCTs to test potential clinical generalizability of research findings. The pilot study is limited in numbers and exposure times with which to test for the minor differences between "research subjects" and "clinical patients."

An observational study of the effectiveness and safety of intramuscular olanzapine in the treatment of acute agitation in patients with bipolar mania or schizophrenia/schizoaffective disorder

OBJECTIVE

To determine the effect of intramuscular (IM) olanzapine in severely agitated patients.

METHODS

This was an open-label multicenter 1-week observational study of IM olanzapine treatment in severely agitated inpatients and psychiatric emergency services with bipolar mania (n = 22) or schizophrenia (n = 52). Mean change from baseline to 2 h post-first injection (LOCF) in agitation was assessed by PANSS-Excited Component (PANSS-EC) (score range: 5-35 points) mean change from baseline to 15, 30, 45, 60, 90, and 120 min post-first injection, and visit-wise mean changes from mixed-model repeated measures analysis of variance. Kaplan-Meier survival curve analyses estimated time to categorical response (rating of <or=3 points each PANSS-EC item).

RESULTS

Two hours post-injection of olanzapine (mean dose = 9.9 mg), patients exhibited mild calmness and agitation was significantly reduced by 19.2 +/- 1.0 points (p < 0.001) (mean baseline = 29.0). Over 90% of the patients received only one injection in the first 24 h and 50% had a categorical response within 30 min.

CONCLUSIONS

Severely agitated patients responded rapidly after a single injection of olanzapine with mild levels of sedation and without serious treatment-emergent adverse events.

Lithium treatment reduces suicide risk in recurrent major depressive disorder

OBJECTIVE

Evidence that clinical treatment reduces suicide risk in major depressive disorder (MDD) is limited and inconsistent. Since lithium shows major antisuicidal effects in bipolar disorders and in heterogeneous mood disorder samples, we evaluated evidence of antisuicidal effects of lithium in patients with recurrent MDD.

DATA SOURCES

We searched MEDLINE (January 1966 to April 2006; search terms: lithium, suicide, affective disorder, depression, major depression, and mood disorder) for studies reporting suicides or suicide attempts during treatment with and without lithium in recurrent MDD patients, and we added data for 78 new subjects, provided from the Lucio Bini Mood Disorders Research Center in Sardinia, Italy. Suicide rates were pooled and analyzed by use of incidence-rate ratios (IRRs) and meta-analytic methods.

DATA SYNTHESIS

Eight studies involved 329 MDD patients and exposure for 4.56 years (1149 person-years) with, and 6.27 years (1285 person-years) without, lithium. Overall risk of suicides and suicide attempts was 88.5% lower with vs. without lithium: 0.17%/y versus 1.48%/y (IRR = 8.71; 95% CI: 2.10 to 77.2, p = .0005); for completed suicides (85% risk reduction), IRR = 6.77 (95% CI: 1.29 to 66.8, p = .01). Meta-analysis by risk difference and risk ratio supported these findings, and sensitivity analysis yielded similar results with studies omitted serially.

CONCLUSIONS

This is the first meta-analysis suggesting antisuicidal effects of lithium in recurrent MDD, similar in magnitude to that found in bipolar disorders.

Weight loss in overweight patients maintained on atypical antipsychotic agents

BACKGROUND

Weight gain and associated medical morbidity offset the reduction of extrapyramidal side effects associated with atypical antipsychotics. Efforts to control weight in antipsychotic-treated patients have yielded limited success.

METHODS

We studied the impact of an intensive 24-week program of diet, exercise, and counseling in 17 chronically psychotic patients (10 women, seven men) who entered at high average body weight (105.0+/-18.4 kg) and body mass index (BMI) (36.6+/-4.6 kg/m(2)). A total of 12 subjects who completed the initial 24 weeks elected to participate in an additional 24-week, less intensive extension phase.

RESULTS

By 24 weeks, weight-loss/patient averaged 6.0 kg (5.7%) and BMI decreased to 34.5 (by 5.7%). Blood pressure decreased from 130/83 to 116/74 (11% improvement), pulse fell slightly, and serum cholesterol and triglyceride concentrations changed nonsignificantly. With less intensive management for another 24 weeks, subjects regained minimal weight (0.43 kg).

CONCLUSIONS

These findings add to the emerging view that weight gain is a major health problem associated with modern antipsychotic drugs and that labor-intensive weight-control efforts in patients requiring antipsychotic treatment yield clinically promising benefits. Improved treatments without weight-gain risk are needed.

Comorbid substance-use in schizophrenia: relation to positive and negative symptoms

As substance use disorders (SUD) are common in schizophrenia patients, we tested the hypothesis that comorbid patients (SUD[+]) have more positive vs. negative symptoms than non-comorbid (SUD[-]) patients. From reports identified by literature-searching we compared Positive and Negative Syndrome Scale (PANSS) ratings in schizophrenia patients with and without SUD using meta-analytic methods. Among 9 comparisons (N=725 subjects), SUD[+] patients were more often men, and abused alcohol>cannabis>cocaine. SUD[+] patients had very significantly higher PANSS-positive, and lower PANSS-negative scores. Comorbid SUD in schizophrenia patients was associated with male sex and higher PANSS positive to lower negative scores. Cause-effect relationships remain to be clarified.

Clinical outcome in patients with bipolar I disorder, obsessive compulsive disorder or both

BACKGROUND

Bipolar disorder (BPD) is often comorbid with obsessive-compulsive (OCD) and other anxiety disorders, but the impact of such comorbidity on long-term outcome has not been evaluated systematically.

METHODS

Extensive follow-up assessments were carried out at 4.3 years after index hospitalizations in a mixed BPD-OCD group (N=20) compared to matched groups with BPD (N=22) or OCD (N=20) alone.

RESULTS

At follow-up, ratings of functional status were similar across groups. Rehospitalizations were similar among BPD-OCD and BPD subjects, but 2.9-times more frequent among comorbid than OCD patients. OCD symptoms averaged 150% more severe in OCD than comorbid subjects, and were not measured in BPD subjects.

CONCLUSIONS

Despite potential sampling bias with previously hospitalized subjects, the findings suggest that comorbid BPD-OCD patients may be clinically more similar to BPD than OCD patients, and that BPD-OCD comorbidity may not negatively impact the long-term clinical outcome.

Use of combinations of antipsychotics: McLean Hospital inpatients, 2002

BACKGROUND

The empirical use of combinations of antipsychotic agents appears to be increasing with little research support for the relative efficacy, safety or cost-effectiveness of this practice. Such treatment was evaluated in hospitalized psychiatric patients.

METHODS

Samples of consecutive inpatients treated with > or = 2 ('polytherapy') vs 1 antipsychotic ('monotherapy') were matched on age, sex, diagnosis and admission clinical ratings, and these groups were compared on total daily chlorpromazine-equivalent doses, days in hospital, and changes in clinical ratings between admission and discharge.

RESULTS

The study sample included 69 polytherapy and 115 well-matched monotherapy subjects. Despite matching for initial CGI and GAF ratings, polytherapy was associated with high PANSS subscale scores of positive symptoms among affective psychosis, and relatively greater PANSS subscale ratings of excitement-agitation among patients diagnosed with schizophrenia. Estimated clinical improvement during hospitalization was similar among poly- and monotherapy patients, but total daily CPZ-eq doses at discharge averaged twice-greater with polytherapy, and hospitalization lasted 1.5 times longer.

CONCLUSIONS

Antipsychotic polytherapy as well as the types of agents combined may reflect clinician responses to particular symptom patterns. The value of specific combinations of antipsychotic agents and their comparison with monotherapies requires specific, prospective, randomized and well-controlled trials that consider matching on clinical characteristics and truly comparable doses across regimens.

Antipsychotic drug use: McLean Hospital, 2002

OBJECTIVE

Major changes in antipsychotic treatment in recent years encouraged a survey of inpatient practice in 2002, compared with earlier samples.

METHODS

Based on records of a random sample of McLean Hospital inpatients prescribed antipsychotics in 2002, the study recorded DSM-IV discharge diagnosis, all psychotropic treatments and doses, initial, peak and final doses of all antipsychotics, clinical status at admission and discharge, and adverse effects reported. Results were compared with similar data from our earlier surveys.

RESULTS

Subjects were 344 inpatients (n = 202 women, 59%), diagnosed with psychotic (n = 102, 30%), bipolar (n = 93, 27%), major depressive (n = 67, 19.5%), dementia (n = 19, 5.5%), substance-use (n = 28, 8%) or other psychiatric disorders (n = 35, 10%). Second-generation antipsychotics accounted for 88% of antipsychotic prescriptions; 17% of patients received > or = 2 antipsychotics and total CPZ-eq discharge does in 2002 averaged 291 +/- 305 mg/day (22% less than a 1998 peak). Doses were unrelated to age, but higher in men, among psychotic vs major affective disorder patients, and with greater illness-severity and longer hospitalization. There was a 3.3-fold increase in the simultaneous use of > or = 3 psychotropic agents since 1998.

CONCLUSIONS

The use of second-generation antipsychotics dominates current inpatient practice. Total antipsychotic dosing has not increased recently, but the use of multiple psychotropics increased strikingly from 1998 to 2002.

Aripiprazole: initial clinical experience with 142 hospitalized psychiatric patients

BACKGROUND

Aripiprazole is the first dopamine D2 receptor partial-agonist approved for treatment of schizophrenia. Its apparently benign adverse-effect profile encourages broader use in other disorders, especially to limit weight gain associated with other antipsychotic or antimanic agents. We considered the first 6 months of experience with aripiprazole in psychiatric inpatients with a range of disorders.

METHODS

We analyzed data obtained from medical records of patients treated with aripiprazole who were hospitalized at McLean Hospital (for 19 +/- 18 days) between December 2002 and June 2003 to evaluate dosing, tolerability, and clinical effects of this new agent in patients diagnosed with DSM-IV psychotic, major affective, or other disorders.

RESULTS

Out of a sample of 2766 adult inpatients (65.5% women), 142 were given aripiprazole (mean final daily dose, 16.1 +/- 6.2 mg, 0.20 +/- 0.09 mg/kg body weight) for major affective disorders (52%), primary psychotic disorders (40%), and dementia (8%). CGI ratings improved by 20% on average. Adverse effects were infrequent (15.5%), were three times more likely among women, and most often involved moderate behavioral activation or nausea, with no new episodes of mania. Of the patients who were given aripiprazole, 83% continued it at discharge. Many patients were obese when they were admitted, and obesity was associated with relatively low mg/kg doses of aripiprazole.

CONCLUSIONS

Aripiprazole was used in a range of disorders and was generally well tolerated. Adverse effects may reflect its unique dopamine partial-agonist activity. Since aripiprazole is likely to be considered for obese patients, body weight should be considered in establishing adequate doses. Controlled trials of this antipsychotic agent in disorders other than schizophrenia are needed.

Ziprasidone: first year experience in a hospital setting

BACKGROUND

The antipsychotic drug ziprasidone, FDA-approved and introduced in the United States in February 2001 for the treatment of schizophrenia, appears to have similar efficacy but better tolerability than older antipsychotics and requires further evaluation under clinical conditions.

METHODS

We analyzed medical records of McLean Hospital inpatients treated with ziprasidone between March 2001 and February 2002, gathering data on DSM-IV diagnoses, presenting symptoms, dosing, concomitant psychotropic medications, clinical changes, adverse effects, and electrocardiographic (ECG) findings.

RESULTS

Ziprasidone was given to 151 inpatients (3.4% of admissions; 108 women, 43 men), aged 37.5 +/- 11.4 years, who presented with depression (n = 79), psychosis (n = 46), mania (n = 18), bipolar mixed-states (n = 4), or other conditions (n = 4). Daily doses averaged 49.8 +/- 34.1 mg initially and 83.2 +/- 46.3 mg at discharge; the greatest dose increases during hospitalization (by a mean of 61%) were in patients with schizoaffective disorder (n = 46; 30% of cases). In 41 cases (27%), ziprasidone was the only antipsychotic at discharge; in 61 (40%) it was used with other antipsychotics. Ziprasidone was discontinued during hospitalization in 49 cases (32.5%), due to lack of efficacy (n = 26; 17.2%), adverse effects (n = 13, 8.6%), or reasons not stated (n = 10, 6.6%). Of 70 patients for whom ECG data were obtained during treatment with ziprasidone, 8 (11%) had QTc intervals > 450 msec during treatment, but none of the 39 patients with ECGs both before and during ziprasidone treatment showed clinically meaningful increases in QTc intervals. Ziprasidone was discontinued in 4 patients (2.6%) due to concern about QTc intervals, but in no case was the QTc interval > or = 500 msec or associated with clinical cardiac toxicity. Improvements in CGI and GAF scores from admission to discharge were similar across diagnoses and unrelated to length of stay or ziprasidone dose.

CONCLUSIONS

Ziprasidone was well tolerated by hospitalized patients with various major psychiatric disorders and may be of value in conditions other than schizophrenia.

Clinical comparison of extended-release divalproex versus delayed-release divalproex: pooled data analyses from nine trials

Divalproex sodium is an effective anticonvulsant, antimanic, and migraine prophylaxis agent. Recently, a new extended-release (ER) formulation of divalproex sodium has become available, which allows for once-daily dosing and provides prolonged therapeutic serum levels. Using data pooled from nine open-label trials involving 321 epilepsy and psychiatry patients, we compared the efficacy and tolerability of divalproex ER with preceding treatment with the older delayed-release (DR) formulation, based on patient reports and analysis by McNemar's test for within-subject paired data. Divalproex ER was associated with superior tolerability with less frequent tremor, weight gain, and gastrointestinal complaints (all P<0.001), but not less hair loss. Divalproex ER also yielded improved seizure control and greater improvement of psychiatric symptoms, and was greatly preferred by patients over divalproex DR. Although the results of the current analyses must be considered highly tentative due to the open-label nature of the trials included, the findings do suggest broad clinical superiority of the new ER preparation.

Multiple versus single antipsychotic agents for hospitalized psychiatric patients: case-control study of risks versus benefits

OBJECTIVE

Since use of multiple drugs to treat psychiatric patients is increasing, and research on this practice is rare, the authors carried out a retrospective case-control study of multiple versus single antipsychotic treatment in psychiatric inpatients.

METHOD

Inpatient treatment groups receiving either antipsychotic monotherapy or polytherapy were matched in terms of age, sex, diagnostic category, and admission clinical ratings (Global Assessment of Functioning [GAF] and Clinical Global Impression [CGI]), which yielded 70 subject pairs. They were compared in terms of total chlorpromazine-equivalent daily dose, changes in total daily dose, length of hospitalization, incidence of adverse effects, and changes in clinical ratings (CGI, GAF, Positive and Negative Syndrome Scale score) between admission and discharge.

RESULTS

Initial doses were closely similar at admission for both treatment groups, but the median total final antipsychotic dose was 78% higher for those receiving antipsychotic polytherapy versus monotherapy. Also, median length of stay in the hospital was 55% (8.5 days) longer, and risk of adverse effects was 56% higher with polytherapy, whereas clinical improvement scores were similar (within 11%) for both treatments.

CONCLUSIONS

Short-term treatment with multiple antipsychotics was associated with major increases in drug exposure, adverse events, and time in the hospital but with no apparent gain in clinical benefit. These findings require further testing in controlled prospective studies.

Efficacy of olanzapine and olanzapine-fluoxetine combination in the treatment of bipolar I depression

BACKGROUND

Despite the longer duration of the depressive phase in bipolar disorder and the frequent clinical use of antidepressants combined with antipsychotics or mood stabilizers, relatively few controlled studies have examined treatment strategies for bipolar depression.

OBJECTIVE

To examine the use of olanzapine and olanzapine-fluoxetine combination in the treatment of bipolar I depression.

DESIGN

Double-blind, 8-week, randomized controlled trial.

SETTING

Eighty-four sites (inpatient and outpatient) in 13 countries. Patients A total of 833 randomized adults with bipolar I depression with a Montgomery-Asberg Depression Rating Scale (MADRS) score of at least 20. Intervention Patients were randomly assigned to receive placebo (n = 377); olanzapine, 5 to 20 mg/d (n = 370); or olanzapine-fluoxetine combination, 6 and 25, 6 and 50, or 12 and 50 mg/d (n = 86).

MAIN OUTCOME MEASURE

Changes in MADRS total scores using mixed-effects model repeated-measures analyses.

RESULTS

During all 8 study weeks, the olanzapine and olanzapine-fluoxetine groups showed statistically significant improvement in depressive symptoms vs the placebo group (P<.001 for all). The olanzapine-fluoxetine group also showed statistically greater improvement than the olanzapine group at weeks 4 through 8. At week 8, MADRS total scores were lower than at baseline by 11.9, 15.0, and 18.5 points in the placebo, olanzapine, and olanzapine-fluoxetine groups, respectively. Remission criteria were met by 24.5% (87/355) of the placebo group, 32.8% (115/351) of the olanzapine group, and 48.8% (40/82) of the olanzapine-fluoxetine group. Treatment-emergent mania (Young Mania Rating Scale score <15 at baseline and > or =15 subsequently) did not differ among groups (placebo, 6.7% [23/345]; olanzapine, 5.7% [19/335]; and olanzapine-fluoxetine, 6.4% [5/78]). Adverse events for olanzapine-fluoxetine therapy were similar to those for olanzapine therapy but also included higher rates of nausea and diarrhea.

CONCLUSIONS

Olanzapine is more effective than placebo, and combined olanzapine-fluoxetine is more effective than olanzapine and placebo in the treatment of bipolar I depression without increased risk of developing manic symptoms.

Oxcarbazepine: clinical experience with hospitalized psychiatric patients

BACKGROUND

Oxcarbazepine (10-keto-carbamazepine) appears to be better tolerated and simpler to use than carbamazepine. It has antimanic effects but, as its potential clinical usefulness and tolerability in broad samples of psychiatric patients remain to be tested, we reviewed both the pharmacology of oxcarbazepine and our early experience with this new agent among psychiatric inpatients.

METHODS

We reviewed medical records of all inpatients given oxcarbazepine in the first 15 months of its use at McLean Hospital. Data analyzed included dosing, presenting illnesses, other medications, clinical changes, and adverse effects.

RESULTS

Oxcarbazepine was given to 56 inpatients (1.3% of admissions; 31 women, 25 men) presenting with depression (n = 23), mania (n = 19), or psychosis (n = 14). The discharge daily dose for the 43 patients (76%) taking oxcarbazepine was 831 mg/day, 34% higher in men than women, and fell by 9 mg/year-of-age. Oxcarbazepine was the only putative mood-stabilizing agent given at discharge in 19 of 43 cases (44%). It was discontinued in 20% of patients for apparent inefficacy, and 4% for adverse effects. Changes in CGI and GAF scores were similarly high across illnesses, and unrelated to days of use of oxcarbazepine or its dose.

CONCLUSIONS

Oxcarbazepine was well tolerated and simpler to use clinically than its precursor carbamazepine. This agent should be studied in controlled trials to test its efficacy in specific types of major psychiatric disorders, and particularly for long-term maintenance treatment in bipolar disorder.

Delirium during clozapine treatment: incidence and associated risk factors

BACKGROUND

Incidence and risk factors for delirium during clozapine treatment require further clarification.

METHODS

We used computerized pharmacy records to identify all adult psychiatric inpatients treated with clozapine (1995-96), reviewed their medical records to score incidence and severity of delirium, and tested associations with potential risk factors.

RESULTS

Subjects (n = 139) were 72 women and 67 men, aged 40.8 +/- 12.1 years, hospitalized for 24.9 +/- 23.3 days, and given clozapine, gradually increased to an average daily dose of 282 +/- 203 mg (3.45 +/- 2.45 mg/kg) for 18.9 +/- 16.4 days. Delirium was diagnosed in 14 (10.1 % incidence, or 1.48 cases/person-years of exposure); 71.4 % of cases were moderate or severe. Associated factors were co-treatment with other centrally antimuscarinic agents, poor clinical outcome, older age, and longer hospitalization (by 17.5 days, increasing cost); sex, diagnosis or medical co-morbidity, and daily clozapine dose, which fell with age, were unrelated.

CONCLUSIONS

Delirium was found in 10 % of clozapine-treated inpatients, particularly in older patients exposed to other central anticholinergics. Delirium was inconsistently recognized clinically in milder cases and was associated with increased length-of-stay and higher costs, and inferior clinical outcome.

Pilot comparison of extended-release and standard preparations of divalproex sodium in patients with bipolar and schizoaffective disorders

OBJECTIVE

The authors compared the new extended-release and standard preparations of divalproex sodium.

METHOD

Twelve patients with DSM-IV bipolar disorder or schizoaffective disorder who were clinically stable while taking the standard form of divalproex participated in the study. These patients were given a single daily dose of the extended-release preparation of divalproex in an open 6-week trial. Clinical symptoms and adverse effects were rated weekly. Doses were adjusted to maintain steady serum valproate concentrations.

RESULTS

The medication change was associated with negligible changes in clinical status and tolerability. To maintain serum drug levels, however, 21% higher doses of the extended-release preparation were required.

CONCLUSIONS

Use of extended-release divalproex once a day was as well tolerated as the standard preparation, with no change in efficacy within 6 weeks, but the daily dose needed to maintain stable serum valproic acid concentration was 21% higher.

Inpatient antipsychotic drug use in 1998, 1993, and 1989

OBJECTIVE

Patterns of clinical use of antipsychotic agents have changed greatly in the past decade. The authors' goal was to examine these patterns.

METHOD

They evaluated medication use in all McLean Hospital inpatients treated with antipsychotic drugs during 3 months in 1998 (N=349) and compared the results with McLean Hospital inpatients treated with antipsychotics in 1993 (N=299) and Boston area inpatients in 1989 (N=50).

RESULTS

The most commonly prescribed antipsychotics in 1998 were atypical agents; olanzapine was prescribed more often than risperidone or quetiapine, which were prescribed more often than other antipsychotics. Two or more antipsychotics were prescribed at some time during their hospitalization for 150 (43%) of the patients in 1998. The total discharge dose in chlorpromazine equivalents for the 349 patients for whom antipsychotics were prescribed at discharge was 371 mg/day, 29% higher than the total discharge dose for patients in 1993 and 46% greater than the dose in 1989. The dose of antipsychotics was greater for patients with psychotic illnesses than for those with affective illnesses. Higher doses were associated with greater clinical improvement, polypharmacotherapy, and younger patient age.

CONCLUSIONS

Emerging trends toward higher total antipsychotic doses and polypharmacotherapy require critical assessments of cost-benefit relationships.

Weygandt's On the Mixed States of Manic-Depressive Insanity: a translation and commentary on its significance in the evolution of the concept of bipolar disorder

Wilhelm Weygandt's Uber die Mischzustände des manisch-depressiven Irreseins (On the Mixed States of Manic-Depressive Insanity) describes and conceptualizes mixed states of mood, behavior, and thinking commonly found in manic-depressive disorders. These ideas emerged from Weygandt's service in the 1890s at the Psychiatric Clinic of the University of Heidelberg, directed by Emil Kraepelin. In the sixth (1899) edition of Kraepelin's influential textbook, the concept of manic-depressive illnesses underwent a fundamental shift from a complex group of syndromal subtypes to a single integrated disorder, widely known from the 1921 English translation of the eighth (1920) edition. In the 1899 edition, Kraepelin acknowledged Weygandt for a new section on mixed manic-depressive states within the new integrated view of manic-depressive disorder. We provide biographical notes on Weygandt, a little-known but historically important figure, as well as the first English translation of his monograph and interpretive summaries of his findings. We also consider whether Weygandt's important insight that the same person could be both manic and depressed not only at different times but even at the same time served as an important stimulus to Kraepelin's unified manic-depressive disorder concept, which survives as bipolar disorder a century later.

Advances in atypical antipsychotics for the treatment of schizophrenia: new formulations and new agents

Innovation in atypical antipsychotic agents continues with new preparations of available drugs as well as novel agents. In this article, we provide an update on these novel products by reviewing information from a computerised literature search, recent abstracts and discussions with industry representatives. A generic formulation of clozapine is now available. It may be less well absorbed and/or less effective than Clozaril, although evidence is conflicting. A fatty acid amide derivative of clozapine is in early development. A liquid formulation of risperidone is currently available, which may be a useful treatment for psychotic agitation as well as a preferable alternative to tablets for some patients. A depot formulation is in development for the long-term management of psychosis. An orally disintegrating tablet formulation of olanzepine is a useful alternative to standard tablets. A short-acting injectable formulation of the drug is in development for psychotic agitation. Sachets and slow-release formulations of quetiapine are in development. Ziprasidone, a recently launched agent, is available in tablet form for schizophrenia/schizoaffective disorder, psychotic depression and mania. A short-acting injectable formulation is in development for psychotic agitation. Aripiprazole (tablets) and iloperidone (tablets and depot injection) are two antipsychotics in development for schizophrenia/schizoaffective disorder (available information regarding iloperidone is very limited). These new formulations and agents should broaden options for the treatment of psychosis.

EEG abnormalities during treatment with typical and atypical antipsychotics

OBJECTIVE

Clozapine produces EEG abnormalities and dose-dependent risk of epileptic seizures. Much less is known about EEG effects of newer antipsychotics. The present study therefore examined the risk of EEG abnormalities associated with various antipsychotic drugs.

METHOD

EEG recordings from 323 hospitalized psychiatric patients (293 treated with antipsychotics, 30 who did not receive any antipsychotic treatment) were graded blind to diagnosis and treatment for type and severity of EEG abnormalities. Drug type, dose, and clinical factors were evaluated for association with EEG abnormalities by multivariate logistic regression.

RESULTS

EEG abnormalities occurred in 56 subjects (19.1%) treated and four (13.3%) not treated with antipsychotics. EEG abnormality risk among antipsychotic agents varied greatly (clozapine=47.1%, olanzapine=38.5%, risperidone=28.0%, typical neuroleptics=14.5%, quetiapine=0.0%). Significant risk factors in order of influence were hypertension, use of an atypical antipsychotic, bipolar diagnosis, and older age; benzodiazepine cotreatment lowered risk. Unassociated with risk were sex, treatment response, length of hospital stay, drug potency, daily dose (in mg or mg/kg), drug exposure time, or cotreatments.

CONCLUSIONS

EEG abnormality risk varied widely among specific antipsychotics. Risk was particularly high with clozapine and olanzapine, moderate with risperidone and typical neuroleptics, and low with quetiapine. Comorbid hypertension, bipolarity, and older age-but not dose or clinical response-were associated with risk.

Factors associated with noncompliance with psychiatric outpatient visits

Adherence to recommended services is essential for long-term effectiveness of ambulatory treatment programs, but factors associated with such adherence are not securely established. We evaluated attendance at 896 scheduled psychiatric clinic visits for 62 patients at a major psychiatric teaching hospital. Visit adherence was found to be significantly higher among patients in an acute stage of illness, those with a personality disorder, those with a post-high-school education, and those living alone. Adherence was also higher when visits were routinely scheduled, when the intervisit interval was shorter, and when the visit entailed psychotherapy rather than pharmacotherapy.

Olanzapine versus placebo in the treatment of acute mania. Olanzapine HGEH Study Group

OBJECTIVE

The primary intent of this study was to compare the efficacy and safety of olanzapine and placebo in the treatment of acute mania.

METHOD

The design involved a random-assignment, double-blind, placebo-controlled parallel group study of 3 weeks' duration. After a 2- to 4-day screening period, qualified patients were assigned to either olanzapine (N = 70) or placebo (N = 69). Patients began double-blind therapy with either olanzapine, 10 mg, or placebo given once per day. After the first day of treatment, the daily dose could be adjusted upward or downward, as clinically indicated, by one capsule (olanzapine, 5 mg/day) within the allowed range of one to four capsules. The primary efficacy measure in the protocol was defined as a change from baseline to endpoint in total score on the Young Mania Rating Scale. Clinical response was defined a priori as a decrease of 50% or more from baseline in Young Mania Rating Scale total score.

RESULTS

The olanzapine group experienced significantly greater mean improvement in Young Mania Rating Scale total score than the placebo group. On the basis of the clinical response criteria, significantly more olanzapine-treated patients (48.6%) responded than those assigned to placebo (24.2%). Somnolence, dizziness, dry mouth, and weight gain occurred significantly more often with olanzapine. There were no statistically significant differences between the olanzapine-treated and placebo-treated patients with respect to measures of parkinsonism, akathisia, and dyskinesias. No discontinuations of treatment due to adverse events occurred in the olanzapine treatment group.

CONCLUSIONS

The results from this study suggest that compared with placebo, olanzapine has superior efficacy for the symptoms of acute mania.

Polymorphisms of the dopamine D4 receptor and response to antipsychotic drugs

The dopamine D4 receptor may be a site through which the clinical effects of antipsychotic drugs are mediated. Polymorphisms of a 48 base pair repeat in the third exon of the DRD4 gene code for different length segments in the third intracytoplasmic loop of the D4 receptor. The most common long (seven repeat) form of the D4 receptor has been shown in both physiologic and pharmacologic experiments to respond differently to dopamine agonists and antagonists than do shorter forms of D4. Thus, variants of D4 may partly determine patient response to antipsychotic drugs and, in particular, response to typical neuroleptics, which have a relatively low affinity for the D4 receptor, as compared to clozapine, which has a relatively high affinity for D4. DRD4 polymorphisms in the third intron were characterized in 28 patients with chronic psychosis who responded well to typical neuroleptics, 32 patients who responded well to clozapine, and 57 healthy comparison subjects. Patients responding to typical neuroleptics carried the allele for the long (seven repeat) form of the D4 receptor (allele frequency 8.9%) less frequently than patients responding to clozapine (allele frequency 23.4%, P = 0.046) or healthy comparison subjects (allele frequency 26.3%, P = 0.004). The results of this study suggest that inherited variants of D4 may explain some of the interindividual variation seen in patient response to different classes of antipsychotic medication.

Clozapine and body mass change

BACKGROUND

Patients treated with clozapine have been reported to gain weight. We hypothesized that patients would also experience an increase in body mass, which can be more directly related to cardiovascular morbidity.

METHODS

Forty-two patients who had been treated with clozapine for at least 1 year were weighed and measured, and waist-hip ratios (WHR) and body mass index (BMI), measured as kg/m2, were calculated. Patients were also asked about a series of factors potentially related to change in body mass.

RESULTS

Female patients gained both weight and body mass. Their WHR after 37 months of clozapine therapy was .83, with a significant increase in BMI from 23.2 to 29.1 kg/m2 (p = .001). Male subjects also gained weight and body mass. Their WHR after 39 months of clozapine therapy was .93, with a significant increase in BMI from 26.4 to 29.7 kg/m2 (p < .001). Stepwise multiple-regression analysis showed that factors related to final body mass were initial body mass, dose of clozapine, and decrease in smoking. Baseline BMI contributed most to the final BMI, but the addition of dose and decrease in smoking made significant contributions to the model.

CONCLUSIONS

Both female and male patients treated with clozapine gain body mass. This may place them at greater risk for cardiovascular morbidity.

The effect of clozapine on saliva flow rate: a pilot study

This study examined the effect of clozapine on saliva flow rate. Unstimulated whole saliva was collected from 9 patients taking clozapine (dose range = 50-400 mg/day) and from 8 controls who had never used clozapine. There was no significant difference between the average saliva flow rates in the two groups (p > .10), nor was there significant correlation between saliva flow rate and daily clozapine dose (p > .10). Alternative explanations for observations or complaints of excessive salivation, drooling, or a choking feeling while taking clozapine are proposed.

Clinically significant interactions of psychotropic agents with antipsychotic drugs

Various psychotropic drugs are commonly combined with antipsychotic agents. Such combinations can induce pharmacodynamically based, presumably additive, beneficial (e.g. sedative or mood-altering) effects or adverse autonomic, cardiac depressant and CNS intoxicating effects. Clinically significant interactions also arise through competition with or induction of hepatic microsomal cytochrome P450 (CYP) enzymes, particularly the CYP1A2 and CYP2D6 isozymes by which most antipsychotics are oxidised. Such pharmacokinetic interactions can elevate circulating concentrations of antipsychotics (both typical agents and the atypical antipsychotic clozapine) to potentially toxic ranges, which may lead to increased risks of adverse effects. Such interactions occur particularly with serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitor antidepressants. Metabolic interactions that lead to lesser increases in antipsychotic concentrations may arise in combining these drugs with other antidepressants, benzodiazepines or propranolol. In contrast, most anticonvulsants, except valproic acid (sodium valproate), induce the oxidative metabolism of antipsychotics and can lower their plasma concentrations to potentially subtherapeutic levels, with unpredictable increases after their discontinuation. Since simultaneous use of multiple psychotropic agents is increasingly common, special caution is required to avoid untoward consequences of interactive adverse effects due to drug interactions, which can sometimes be severe or life-threatening.

Risperidone in the treatment of mania

BACKGROUND

Risperidone, a 5-HT2 and D2 antagonist, has been shown to be an effective antipsychotic in the treatment of schizophrenia but has unclear efficacy in the treatment of psychotic affective disorders. The purpose of the study was to assess the efficacy of risperidone in the treatment of acute mania with psychotic features.

METHOD

We conducted an open-label pilot study of risperidone and concurrent mood-stabilizing drugs in the treatment of acute mania with psychotic features. Patients were diagnosed with the Structured Clinical Interview for DSM-III-R (SCID). Efficacy was measured weekly with the use of the Young Mania Rating Scale (YMRS) and the Brief Psychiatric Rating Scale (BPRS).

RESULTS

Ten women and 5 men (mean age = 38 years) were included in the study. Of the 13 patients who completed 2 weeks of treatment, 8 of these 13 had a 50% improvement of the BPRS, and all 13 had at least a 25% improvement (p = .002, 95% confidence interval [CI] = 46.0 to 57.8). Of the 8 patients who completed 6 weeks of treatment, 7 of the 8 had a 50% improvement, and all 8 had a 25% improvement (p = .012, 95% CI = 52.4 to 69.3). Similar results were obtained with the YMRS. By the second week of treatment, 10 of the 13 patients remaining in treatment had at least a 50% improvement, and 12 of these 13 had a 25% improvement (p = .002, 95% CI = 55.1 to 89.9). By the sixth week, all of the 8 patients remaining in treatment had a 75% improvement (p = .012, 95% CI = 90.5 to 102.8). The medication was well tolerated, and no case worsened.

CONCLUSION

When used with concomitant mood-stabilizing drugs, risperidone may be effective and well tolerated in patients with acute mania with psychotic features. Considering the open design, small sample size, and limited period of observation, further studies need to be conducted.

Serum levels of clozapine and norclozapine in patients treated with selective serotonin reuptake inhibitors

OBJECTIVE

The selective serotonin reuptake inhibitor (SSRI) fluoxetine can increase serum levels of clozapine and norclozapine, but effects of other SSRIs are unknown. Thus, the authors evaluated interactions of clozapine with fluoxetine, paroxetine, and sertraline.

METHOD

Serum clozapine and norclozapine concentrations were assayed in 80 psychiatric patients, matched for age and clozapine dose, given clozapine (mean dose = 279 mg/day) alone or with fluoxetine (mean dose = 39.3 mg/day), paroxetine (mean = 31.2 mg/day), or sertraline (mean = 92.5 mg/ day). Each patient's dose of clozapine was stable for at least a month before serum sampling.

RESULTS

Concentrations of clozapine plus norclozapine averaged 43% higher, and the risk of levels higher than 1000 ng/ml was 10-fold greater (25%), in the patients taking SSRIs, with minor differences between patients taking the individual SSRIs.

CONCLUSIONS

SSRIs can increase circulating concentrations of clozapine and norclozapine, sometimes to potentially toxic levels.

Hospital use of antipsychotic agents in 1989 and 1993: stable dosing with decreased length of stay

OBJECTIVE

This study evaluated recent and current use of antipsychotics by psychiatric inpatients.

METHOD

Computer-based hospital pharmacy records identified prescriptions for antipsychotics in 1993. Medical records were reviewed to verify prescription and clinical data, and these were compared with similar data from 1989.

RESULTS

In 1993, antipsychotics were prescribed for 299 (42%) of 709 hospitalized patients. Treatment usually started within 24 hours of admissions averaging 18 days. High-potency agents were used 2.4 times more frequently than low-potency drugs; 13% received clozapine. The mean chlorpromazine-equivalent daily dose, corrected for as-needed supplements, was 305 mg; peak doses were 32% higher. Doses of the most potent agents (fluphenazine and haloperidol) were only 22%-33% above the overall mean. Rarely were two neuroleptics given simultaneously, but cotreatment with an anticonvulsant (84% of patients, 92% of whom received valproate), a potent benzodiazepine (81%), lithium (70%), one CNS depressant (84%), or more (45%) was common. Doses averaged 20% higher for men, 42% lower at age > 50 years versus 20-30 years, and 53% greater for schizophrenia or schizoaffective disorder versus other conditions. Comparison with 1989 admissions (N = 50) averaging 73 days indicated few differences in use of neuroleptics or benzodiazepines but less frequent use of anticonvulsants and lithium.

CONCLUSIONS

High-potency antipsychotic agents and clozapine were used most often in 1993; doses of high-potency agents were only slightly higher than doses of low-potency agents, but combinations with mood stabilizers were more common in 1993, when length of stay was one-fourth that in 1989.

Relation of leukocyte counts during clozapine treatment to serum concentrations of clozapine and metabolites

OBJECTIVE

This study was done to test the hypothesis that serum concentration of norclozapine is a risk factor for leukopenia during treatment with clozapine.

METHOD

Maximum decreases in leukocyte counts in 44 unselected patients treated with clozapine were determined and then correlated with drug doses and serum concentrations of clozapine, norclozapine, and clozapine-N-oxide.

RESULTS

White cell and granulocyte counts decreased by up to 60%-73%, but there were no positive correlations between these decrements and drug dose, drug level, ratio of drug level to drug dose, or ratio of norclozapine level to clozapine level, nor were the decreases related to age or gender.

CONCLUSIONS

While these results do not suggest in vivo hemotoxicity of norclozapine, further study of patients with clinically significant leukopenia is required.

Concurrent use of clozapine and valproate in affective and psychotic disorders

BACKGROUND

This pharmaco-epidemiologic study was undertaken to determine if the combination of clozapine and valproate poses an increased risk of blood dyscrasias, liver function abnormalities, or other side effects and to develop dosing guidelines when the combination is utilized.

METHOD

The charts of 55 patients receiving clozapine and valproate concurrently between May 8, 1989, and May 8, 1992, were reviewed to determine the indication for and length of time on each medication, abnormalities in liver function test results, blood cell dyscrasias, seizures, nausea, vomiting, sedation, sialorrhea, and enuresis. In addition, the efficacy of the combination was measured.

RESULTS

The combination of clozapine and valproate was efficacious and well tolerated in the majority of patients. Major adverse effects such as blood dyscrasias or seizures were not experienced by the study population. The side effect that led to discontinuation of the combination most frequently was sedation.

CONCLUSION

The combination of clozapine and valproate is safe and efficacious.

Clozapine and metabolites: concentrations in serum and clinical findings during treatment of chronically psychotic patients

Clozapine (CLZ) and metabolites norclozapine and clozapine-N-oxide were assayed with a new, sensitive (2 pmol), and selective method in 68 serum samples from 44 psychotic subjects, 20 to 54 years old, ill 16 years, and treated with CLZ for 2.2 years (currently at 294 mg, 3.4 mg/kg daily). CLZ levels averaged 239 ng/ml (0.73 microM; 92 ng/ml per mg/kg dose) or 48% of total analytes (norclozapine = 41% [91% of CLZ] and clozapine-N-oxide = 11%); metabolite and CLZ levels were highly correlated (rs = 0.9), and CLZ levels varied with daily dose (rs = 0.7). Sampling twice yielded similar within-subject analyte levels (r = 0.8 to 0.9; difference = 24% to 33%). Range and variance narrowed when levels were expressed per weight-corrected dose (ng/ml per mg/kg). Levels per dose were 40% higher in nonsmoking women than men, despite a 60% lower milligram per kilogram dose in women, and did not vary by diagnosis or age in this limited sample. Fluoxetine increased serum CLZ analytes by 60%; valproate had less effect. Patients rated treatment very positively; observer-assessed benefits typically were more moderate. Common late side effects were sialorrhea (80%), excess sedation (58%), obesity (55% > 200 lb), mild tachycardia (51%), constipation (32%), and enuresis (27%); there were no seizures or leukopenia. There was little evident relationship of drug dose or serum level to current clinical measures or side effect risks.

Serum concentrations of clozapine and its major metabolites: effects of cotreatment with fluoxetine or valproate

Serum concentrations of clozapine, norclozapine, and clozapine-N-oxide were assayed in psychotic patients treated with clozapine alone (N = 17), clozapine with fluoxetine added (N = 6), or clozapine with valproic acid added (N = 11). Subjects were matched for age and other treatments, and concentrations were corrected for daily dose of clozapine (milligrams per kilogram of body weight). With valproic acid, there was a minor increase in total clozapine metabolites, which was even less with dose correction. Fluoxetine increased all clozapine analytes, in some cases to twice the levels in the subjects given only clozapine.

Tissue concentrations of clozapine and its metabolites in the rat

Clozapine (CLZ) and its metabolites norclozapine (NOR) and clozapine-N-oxide (NOX) were assayed in rat serum and brain tissue after intraperitoneal injection of CLZ. Clozapine levels rose with dose, averaging 28 ng/ml (87 nmol/L) serum per milligram/kilogram dose. Brain- and serum-CLZ levels correlated closely, averaging 24-fold higher in brain. Norclozapine and NOX averaged approximately 58% and 13% of CLZ in serum, respectively, whereas in brain, NOR was detected only at doses greater than or equal to 10 mg/kg (approximately 5.6% of CLZ) and NOX was undetectable. Levels peaked within 30 minutes, and elimination of CLZ from brain and CLZ or NOR from blood was very rapid (half-life = 1.5 to 1.6 hours). A week of daily dosing with CLZ led to no accumulation of drug in brain; a week of fluoxetine pretreatment increased analyte concentrations (serum, 86%; brain, 61%), but valproate had little effect.

Determination of clozapine, norclozapine, and clozapine-N-oxide in serum by liquid chromatography

We report a new assay to measure the serum concentrations of the atypical antipsychotic drug clozapine and two major metabolites, norclozapine and clozapine-N-oxide. The analytes and an internal standard (triprolidine) were extracted from alkalinized samples into ethyl acetate and back-extracted into 0.1 mol/L HCl. The acid extracts were chromatographed on a reversed-phase liquid chromatographic column with photodiode array detection (210-340 nm). With the 254-nm signal, between-run imprecision (CV) was &lt; 2% for clozapine and norclozapine at 400 micrograms/L, and 4.1% for clozapine-N-oxide at 100 micrograms/L. Absolute recovery exceeded 65%, and the detection limit was approximately 3-4 micrograms/L. In 25 patients at steady state at a mean daily clozapine dosage of 269 mg (3.09 mg/kg), clozapine averaged 231 +/- 144 micrograms/L (mean +/- SD); norclozapine and clozapine-N-oxide concentrations averaged 84% and 23% that of clozapine. Analyte concentrations were significantly correlated with daily dose. The method's ability to quantify clozapine and two major metabolites simultaneously with precision and sensitivity makes it useful in pharmacokinetic studies and therapeutic monitoring.

Determination of clozapine, norclozapine, and clozapine-N-oxide in serum by liquid chromatography

We report a new assay to measure the serum concentrations of the atypical antipsychotic drug clozapine and two major metabolites, norclozapine and clozapine-N-oxide. The analytes and an internal standard (triprolidine) were extracted from alkalinized samples into ethyl acetate and back-extracted into 0.1 mol/L HCl. The acid extracts were chromatographed on a reversed-phase liquid chromatographic column with photodiode array detection (210-340 nm). With the 254-nm signal, between-run imprecision (CV) was < 2% for clozapine and norclozapine at 400 micrograms/L, and 4.1% for clozapine-N-oxide at 100 micrograms/L. Absolute recovery exceeded 65%, and the detection limit was approximately 3-4 micrograms/L. In 25 patients at steady state at a mean daily clozapine dosage of 269 mg (3.09 mg/kg), clozapine averaged 231 +/- 144 micrograms/L (mean +/- SD); norclozapine and clozapine-N-oxide concentrations averaged 84% and 23% that of clozapine. Analyte concentrations were significantly correlated with daily dose. The method's ability to quantify clozapine and two major metabolites simultaneously with precision and sensitivity makes it useful in pharmacokinetic studies and therapeutic monitoring.