The effects of olanzapine, risperidone, and haloperidol on plasma prolactin levels in patients with schizophrenia

Effects of the atypical antipsychotics olanzapine and risperidone on plasma prolactin levels in male rats: a comparison with clinical data

RATIONALE

Hyperprolactinaemia is a common side effect of antipsychotic treatment and the clinical consequences associated with this, e.g. sexual dysfunction, can have a negative impact on patient compliance.

OBJECTIVES

The aim of this study was to investigate the effect of the atypical antipsychotics olanzapine and risperidone on prolactin levels in rats using different treatment regimes and to compare these data with those reported clinically.

METHODS

All experiments were carried out in male CD rats. In separate studies, the effects of acute, sub-chronic (7 days) and chronic (28 days) olanzapine and risperidone administration on prolactin levels were determined. Further studies investigated the time course of the prolactin response following olanzapine and risperidone treatment over 24 h.

RESULTS

Both drugs significantly increased prolactin levels in a similar manner following acute administration, in keeping with clinically reported data. However, this elevation was still present following sub-chronic and chronic treatment, contrasting with clinical data with respect to olanzapine but not risperidone. Over 24 h, olanzapine demonstrated a more transient elevation of prolactin levels, whereas risperidone caused a robust and persistent increase in prolactin up to 24 h post-dose, closely mimicking clinical results.

CONCLUSIONS

The present study has demonstrated that olanzapine and risperidone display similar effects on prolactin levels in the rat following acute and chronic administration but differ in their prolactin response over a 24-h period. In conclusion, prolactin levels in rats following atypical antipsychotic treatment may not be fully predictive of the clinical situation.

Female puberty: clinical implications for the use of prolactin-modulating psychotropics

During puberty, girls may present with psychiatric illness necessitating treatment with psychotropic medications. Pubertal girls are especially vulnerable to medication-associated adverse events. Atypical antipsychotics and antidepressants have the potential to elevate prolactin levels, altering pubertal progression. Selection of prolactin-sparing atypical antipsychotics is recommended, as is treatment with the lowest effective dose of selective serotonin reuptake inhibitors. Monitoring of serum prolactin levels may be necessary.

Effect of therapy with atypical antipsychotic drugs on prolactin concentration in patients with schizophrenia and schizoaffective disorders

Plasma prolactin concentration was measured in patients with schizophrenia and schizoaffective disorders receiving therapy with risperidone, olanzapine, and quetiapine and compared with the corresponding parameter in patient receiving typical neuroleptic drug haloperidol. We evaluated the specific effects of the test drugs on prolactin concentration in men and women.

Amoxapine as an atypical antipsychotic: a comparative study vs risperidone

Amoxapine is marketed as an antidepressant. However, its in-vitro profile, receptor occupancy and preclinical effects are very similar to atypical antipsychotics. Amoxapine has also shown efficacy as an atypical antipsychotic in open trials. The objective of this study was to compare the antipsychotic and side effect profile of amoxapine and risperidone in a randomised assignment, standardized dosing, double-blind trial of acutely psychotic patients with schizophrenia. A total of 48 schizophrenic patients were enrolled and randomized in a double-blind 6-week trial to receive either risperidone (up to 5 mg/day) or amoxapine (up to 250 mg/day). Positive, negative, affective symptoms and motor side effects were measured using standardized weekly assessments. Prolactin levels were also determined at baseline and at the end of the study. A total of 39 patients (amoxapine, n=22; risperidone, n=21) completed the trial. Both pharmacological treatments, amoxapine 228.0 mg/day (SD=34.6) and risperidone 4.5 mg/day (SD=0.7), showed equivalent improvement in positive, negative, and depressive symptoms. Amoxapine was associated with less EPS and less prolactin elevation than risperidone. These data support previous reports about the efficacy of amoxapine as an atypical antipsychotic. Since amoxapine is off-patent, it may be a valuable low-cost alternative to new atypical antipsychotics, particularly in low-income countries where the majority of the patients are still treated with typical antipsychotics.

Validation of the Investigator's Assessment Questionnaire, a new clinical tool for relative assessment of response to antipsychotics in patients with schizophrenia and schizoaffective disorder

The success of long-term therapy in schizophrenia is contingent upon real-world effectiveness or improvements in several domains, including efficacy, safety and tolerability. This report describes the Investigator's Assessment Questionnaire (IAQ), a new 10-item instrument designed to assess relative effectiveness (efficacy, safety and tolerability) of antipsychotic medications in patients with schizophrenia or schizoaffective disorder. To measure content validity, 300 psychiatrists rated the importance of the IAQ items. Efficacy (i.e., positive and negative symptoms) was considered most important, but importance scores relative to the mean ranged only from 0.87 to 1.18, suggesting similar importance of the items. Cronbach's coefficient alpha values showed that the items were internally consistent. Factor analyses indicated that all IAQ items belong to a single domain. Data from the US Broad Effectiveness Trial of Aripiprazole were used for construct validation. Total IAQ score correlated significantly with time to treatment discontinuation (r=-0.50), Clinical Global Impressions-Improvement (CGI-I) score (r=0.76) and medication preference of patients (r=0.71) or caregivers (r=0.70). A one-unit decrease in IAQ score corresponded to an additional 1.35 days in the study and a decrease in CGI-I of 0.21 units. These results provide initial validation of the IAQ as a tool for evaluating antipsychotic response in patients with schizophrenia or schizoaffective disorder.

Does clozapine work by blocking spikes and sparing bursts?

Clozapine works better and produces fewer side effects than other antipsychotics. Existing hypotheses fail to explain why. A new hypothesis, single spike suppression, supposes that psychotic symptoms are mediated by the single spikes of neurons at the D2 receptor. All antipsychotics block these spikes. Clozapine, according to the hypothesis, blocks these spikes but, unlike other antipsychotics, spares the spike bursts that mediate movement, cognition and affect. This study explores the mathematical feasibility of single spike suppression. Could an antipsychotic with the right receptor kinetics selectively block single spikes? Could this selectivity have clinical consequences? To develop the hypothesis, the author made a mathematical model of the receptor occupancy of a synapse, and performed five simulations, varying input data within the range established by research. The effects of hypothetical antipsychotics on single spikes and bursts were compared. The author confirmed that a drug with the right dissociation rate constant (k off) would dissociate slowly enough to block single spikes, but rapidly enough to spare longer bursts. If the hypothesis is correct, this spike-selective, burst-sparing drug would work at relatively low D2 occupancies, and cause minimal D2-related side effects. Single spike suppression may explain the superior properties of clozapine better than competing hypotheses. If so, it would provide a better model for a new generation of safe, effective antipsychotics.

Bipolar disorder in women: reproductive events and treatment considerations

OBJECTIVE

Bipolar disorders are prevalent in women. Women with bipolar disorder often present with different clinical features than men. Reproductive events and hormonal treatments may impact the course of bipolar disorder. Our main objectives are to i) assess the impact of reproductive events on the course of the disorder, and ii) to discuss the relationships between reproductive events and psychiatric treatments.

METHOD

A literature search was conducted of MEDLINE journals from 1965 to present. Manual literature searches were also conducted. We review the presentation, clinical course, and treatment considerations of bipolar disorder in women, with emphasis on treatment considerations in the context of reproductive events. Treatment-related issues such as teratogenicity, breastfeeding, polycystic ovarian syndrome, weight gain and obesity, and medication interactions with oral contraceptives are reviewed.

RESULTS

Women with bipolar disorder may be more vulnerable to mood episodes in the context of reproductive events, particularly postpartum. In women of reproductive age, mood stabilizers must be selected with teratogenic risks in mind, with the highest reported risks in pregnancy with valproate, and the greatest concern during breastfeeding with lithium use. In the areas of the perimenopause and polycycstic ovarian syndrome, more data are needed to advise treatment decisions.

CONCLUSION

We urgently need further study in these areas to deliver care that is appropriate to women with bipolar disorder.

Medication-induced hyperprolactinemia

Medication use is a common cause of hyperprolactinemia, and it is important to differentiate this cause from pathologic causes, such as prolactinomas. To ascertain the frequency of this clinical problem and to develop treatment guidelines, the medical literature was searched by using PubMed and the reference lists of other articles dealing with hyperprolactinemia due to specific types of medications. The medications that most commonly cause hyperprolactinemia are antipsychotic agents; however, some newer atypical antipsychotics do not cause this condition. Other classes of medications that cause hyperprolactinemia include antidepressants, antihypertensive agents, and drugs that increase bowel motility. Hyperprolactinemia caused by medications is commonly symptomatic, causing galactorrhea, menstrual disturbance, and impotence. It is Important to ensure that hyperprolactinemia in an Individual patient is due to medication and not to a structural lesion in the hypothalamic/pituitary area; this can be accomplished by (1) stopping the medication temporarily to determine whether prolactin levels return to normal, (2) switching to a medication that does not cause hyperprolactinemia (in consultation with the patient's psychiatrist for psychoactive medications), or (3) performing magnetic resonance imaging or computed tomography of the hypothalamic/pituitary area. If the patient's hyperprolactinemia is symptomatic, treatment strategies include switching to an alternative medication that does not cause hyperprolactinemia, using estrogen or testosterone replacement, or, rarely, cautiously adding a dopamine agonist.

Quand et comment traiter une hyperprolactinémie ?

Hyperprolactinemia affects the gonadotropic axis. Its results in women include amenorrhea, menstrual disorders and galactorrhea; in men, the frequency of macroadenomas tends to lead to problems related to sexual performance or tumor volume. Radioimmunoassays make diagnosis easy. Secondary causes of hyperprolactinemia, drug reactions in particular, must be ruled out before MRI exploration to look for a pituitary tumor. First-line treatment of prolactin adenomas is based on the use of dopaminergic agonists, especially cabergoline, because of their excellent efficacy and the risk of relapse following surgery. For patients who wish to become pregnant, the dopaminergic agonist must be continued during pregnancy for those with macroadenoma and withdrawn for women with microadenoma. When hyperprolactinemia is induced by anti-psychotic agents, treatment requires an in-depth assessment.

Retrospective Study of Quetiapine in Children and Adolescents with Pervasive Developmental Disorders

A retrospective study was conducted in a clinic specialized in treating individuals with developmental disabilities to examine the effectiveness and tolerability of quetiapine in children and adolescents with pervasive developmental disorders. Ten consecutive outpatients (age = 12.0 +/- 5.1 years) treated with quetiapine (dose = 477 +/- 212 mg, duration = 22.0 +/- 10.1 weeks) were identified and six were judged to be responders based on impressions from chart review and Conners Parent Scale (CPS). Improvements were observed in the conduct, inattention, and hyperactivity subscales of the CPS. Adverse events were mild with sedation being the most common, and no patient required treatment termination. Quetiapine may be beneficial in children and adolescents with pervasive developmental disorders, however open-label and double-blind, placebo-controlled studies are warranted.

Risperidone versus olanzapine for schizophrenia

BACKGROUND

Antipsychotic medication is a mainstay of treatment for schizophrenia and risperidone and olanzapine are the most popular treatment choice of the new generation drugs.

OBJECTIVES

To determine the clinical effects, safety and cost effectiveness of risperidone compared with olanzapine for treating schizophrenia.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Group's Register (June 2004) which is based on regular searches of, amongst others, BIOSIS, CENTRAL, CINAHL, EMBASE, MEDLINE and PsycINFO. References of all identified studies were inspected for further trials. We also contacted relevant pharmaceutical companies for additional information.

SELECTION CRITERIA

We included all clinical randomised trials comparing risperidone with olanzapine for schizophrenia and schizophrenia-like psychoses.

DATA COLLECTION AND ANALYSIS

We extracted data independently. For homogenous dichotomous data we calculated random effects, relative risk (RR), 95% confidence intervals (CI) and, where appropriate, numbers needed to treat/harm (NNT/H) on an intention-to-treat basis. For continuous data, we calculated weighted mean differences (WMD).

MAIN RESULTS

We found no difference for the outcome of unchanged or worse in the short term (n=548, 2 RCTs, RR 1.00 CI 0.88 to 1.15). One study, sponsored by the manufactures of olanzapine, favoured this drug for the outcome of relapse/rehospitalisation by 12 months (n=279, RR 2.16 CI 1.31 to 3.54, NNT 7 CI 4 to 25). Most mental state data showed the two drugs to as effective as each other (n=552, 2 RCTs, RR 'no <20% decrease PANSS by eight weeks' 1.01 CI 0.87 to 1.16). At least two thirds of people given risperidone or olanzapine experienced an adverse event (n=300, 2 RCTs, RR 1.16 CI 0.70 to 1.94). About 20% had anticholinergic symptoms (n=719, 3 RCTs, RR 1.12 CI 0.77 to 1.63) and 20% of both groups experienced insomnia (n=594, 3 RCTs, RR 1.33 CI 0.95 to 1.85) and approximately 33% sleepiness (n=719, 4 RCTs, 0.99 CI 0.79 to 1.23). One third of people given either drug experienced some extrapyramidal symptoms (n=893, 3 RCTs, RR 1.18 CI 0.75 to 1.88) but 25% of people using risperidone require medication to alleviate extrapyramidal adverse effects (n=419, 2 RCTs, RR 1.76 CI 1.25 to 2.48, NNH 8 CI 4 to 25). People allocated to risperidone were less likely to gain weight compared with those given olanzapine and the weight gain resulting from olanzapine can be considerable and of rapid onset (n=377, 1 RCT, RR gain more than 7% of their baseline weight 0.40 CI 0.23 to 0.70, NNT 8 CI 6 to 17). Risperidone may cause more sexual dysfunction than olanzapine (n=370, 2 RCTs, RR abnormal ejaculation 4.36 CI 1.38 to 13.76, NNH 20 CI 6 to 176; n=31, 1 RCT, RR impotence 2.43 CI 0.24 to 24.07). Within trials both drugs are associated with equal attrition (n=1217, 7 RCTs, RR leaving the study early 1.17 CI 0.92 to 1.49).

AUTHORS' CONCLUSIONS

Data regarding quality of life and economic outcomes are difficult to interpret, and for both these highly marketed new drugs we know very little from evaluative studies regarding service outcomes, general functioning and behaviour, engagement with services and treatment satisfaction. There is little to differentiate between risperidone and olanzapine except on the issue of adverse effects and both these drugs have unpleasant adverse effects. Risperidone is particularly associated with movement disorders and sexual dysfunction. Olanzapine can cause considerable rapid weight gain.This review highlights the need for large, independent, well designed, conducted and reported pragmatic randomised studies.

Antipsychotic drug-induced weight gain: development of an animal model

OBJECTIVE

Weight gain is a prominent effect of most atypical antipsychotic drugs (AAPDs); yet, the mechanisms are not fully understood and no well-established mouse models exist for investigating the mechanisms. Thus, we developed a mouse model to evaluate the effects of AAPDs on eating, body weight (BW), and body composition.

METHODS

Female C57BL/6J mice were used to test olanzapine, quetiapine, ziprasidone, and risperidone. Mice were acclimated to individual housing, given ad libitum access to chow and water, dosed with placebo peanut butter pills for 1 week, and then dosed daily with AAPD-laced peanut butter pills for 4 weeks. Weekly food intakes and BWs were measured, and body compositions were determined at the end of each experiment.

RESULTS

After 4 weeks of treatment, olanzapine, quetiapine, ziprasidone, and risperidone caused significant weight increases, but only olanzapine and quetiapine were associated with significantly increased food intake. Body composition data revealed that olanzapine-treated mice had more relative fat mass and risperidone-treated mice had more relative lean mass than did control mice. Quetiapine and ziprasidone did not significantly affect relative body composition even though BW was increased.

CONCLUSIONS

Oral AAPD administration causes increased BW in female mice. Our mouse model of AAPD-induced weight gain resembles the human response to these medications and will be used to investigate the mechanisms for weight gain and fat accumulation.

Olanzapine vs. other antipsychotics in actual out-patient settings: six months tolerability results from the European Schizophrenia Out-patient Health Outcomes study

OBJECTIVE

The European Schizophrenia Out-patient Health Outcomes study is an observational study investigating treatment in schizophrenia. We report treatment-emergent adverse events during the first 6 months of treatment.

METHOD

The rate of extrapyramidal symptoms (EPS), anticholinergic use, weight gain and sexual related dysfunctions were assessed in 8,400 out-patients.

RESULTS

Patients typical antipsychotics and risperidone experienced significantly more EPS and anticholinergic use than patients in the clozapine, olanzapine, and quetiapine cohorts. Patients treated with amisulpride, typical antipsychotics and risperidone were significantly more likely to have sexual related dysfunctions and/or amenorrhea. Increases in weight and body mass index occurred in all cohorts, but were significantly greater in the olanzapine and clozapine cohorts.

CONCLUSION

Patients treated with olanzapine, quetiapine and clozapine had better tolerability outcomes regarding EPS and sexual related dysfunctions compared with patients receiving risperidone, amisulpride and typicals. Patients treated with olanzapine and clozapine had higher weight increases than patients treated with risperidone, quetiapine and typicals.

Prolactin levels in male schizophrenic patients treated with risperidone and haloperidol: a double-blind and randomized study

RATIONALE

There are few data from systematic, double-blind clinical trials that have compared the effect of the typical and the atypical antipsychotics on serum prolactin (PRL) levels in patients with schizophrenia.

OBJECTIVES

The goal of this study was to compare the effect of risperidone and haloperidol on serum PRL and investigate the relationship between serum PRL levels and clinical response in patients with schizophrenia.

METHODS

Seventy-eight inpatients with a diagnosis of schizophrenia (according to DSM-III-R) were randomly assigned to 12 weeks of treatment with 6 mg/day of risperidone or 20 mg/day of haloperidol after a 2-week washout period, using a randomized, double-blind design. Clinical efficacy was determined using the positive and negative syndrome scale (PANSS). Their serum PRL was assayed by means of radioimmunometric assay (RIA) between pre-treatment and post-treatment, and compared with 30 sex-matched and age-matched normal subjects.

RESULTS

Both risperidone and haloperidol treatment significantly increased serum PRL levels in drug-free chronic schizophrenia patients (both P<0.001). Hyperprolactinemia induced by risperidone 6 mg/kg was comparable to levels produced by haloperidol 20 mg/day. Considering dose-adjusted serum PRL levels, risperidone treatment induced a significant elevation of PRL levels compared with haloperidol treatment at the haloperidol equivalent (P<0.001). Change in PRL levels at pre-treatment and post-treatment were related to positive symptom improvement seen in the risperidone group (r=0.51, P=0.016), but not in the haloperidol group (P>0.05). Female patients showed both a higher baseline and post-treatment PRL level and a greater increase in PRL than men (all P<0.05).

CONCLUSIONS

Risperidone is associated with a robust effect on prolactin secretion in contrast to the conventional antipsychotic haloperidol. Prolactin monitoring during risperidone treatment should be performed.

Antipsychotic-induced hyperprolactinaemia: mechanisms, clinical features and management

Hyperprolactinaemia is an important but neglected adverse effect of antipsychotic medication. It occurs frequently with conventional antipsychotics and some atypical antipsychotics (risperidone and amisulpride) but is rare with other atypical antipsychotics (aripiprazole, clozapine, olanzapine, quetiapine, ziprasidone). For this reason the terms 'prolactin-sparing' and 'prolactin-raising' are more useful than 'atypical' and 'conventional' when considering the effect of antipsychotic drugs on serum prolactin. During antipsychotic treatment prolactin levels can rise 10-fold or more above pretreatment values. In a recent study approximately 60% of women and 40% of men treated with a prolactin-raising antipsychotic had a prolactin level above the upper limit of the normal range. The distinction between asymptomatic and symptomatic hyperprolactinaemia is important but is often not made in the literature. Some symptoms of hyperprolactinaemia result from a direct effect of prolactin on target tissues but others result from hypogonadism caused by prolactin disrupting the normal functioning of the hypothalamic-pituitary-gonadal axis. Symptoms of hyperprolactinaemia include gynaecomastia, galactorrhoea, sexual dysfunction, infertility, oligomenorrhoea and amenorrhoea. These symptoms are little researched in psychiatric patients. Existing data suggest that they are common but that clinicians underestimate their prevalence. For example, well conducted studies of women treated with conventional antipsychotics have reported prevalence rates of approximately 45% for oligomenorrhoea/amenorrhoea and 19% for galactorrhoea. An illness-related under-function of the hypothalamic-pituitary-gonadal axis in female patients with schizophrenia may also contribute to menstrual irregularities. Long-term consequences of antipsychotic-related hypogonadism require further research but are likely and include premature bone loss in men and women. There are conflicting data on whether hyperprolactinaemia is associated with an increased risk of breast cancer in women. In patients prescribed antipsychotics who have biochemically confirmed hyperprolactinaemia it is important to exclude other causes of prolactin elevation, in particular tumours in the hypothalamic-pituitary area. If a patient has been amenorrhoeic for 1 year or more, investigations should include bone mineral density measurements. Management should be tailored to the individual patient. Options include reducing the dose of the antipsychotic, switching to a prolactin-sparing agent, prescribing a dopamine receptor agonist and prescribing estrogen replacement in hypoestrogenic female patients. The efficacy and risks of the last two treatment options have not been systematically examined. Antipsychotic-induced hyperprolactinaemia should become a focus of interest in the drug treatment of psychiatric patients, particularly given the recent introduction of prolactin-sparing antipsychotics. Appropriate investigations and effective management should reduce the burden of adverse effects and prevent long-term consequences.

Treatment in risperidone-induced amenorrhoea

Objective To find the optimal changes needed for resolution of amenorrhoea associated with risperidone. Method Between November 2001 and May 2002, 16 female outpatients who had taken risperidone for more than 3 months voluntarily reported amenorrhoea. Following each report of amenorrhoea, serum prolactin level was measured and treatment changes were undertaken. The menstrual cycles and clinical mental status of each patient were followed for the next 6 months. For nine of the 16 patients, the dose of risperidone was reduced. For the other seven patients, risperidone was switched to olanzapine or quetiapine. Results Fourteen of 16 patients had hyperprolactinemia. Two patients who had discontinuation of risperidone recovered from amenorrhoea and three of the risperidone-reduction patients resumed their periods. All subjects in the drug-switch patients recovered. The patients who recovered from amenorrhoea at a reduced dosage of risperidone took ≤3 mg/day. Two patients in the risperidone-reduction group dropped out. Conclusion Stopping risperidone (without starting any other antipsychotic) or switching to a prolactin-sparing antipsychotic is an effective strategy for resolution of amenorrhoea on risperidone, but that dose reduction is rarely effective either because amenorrhoea continues despite lower dose or because relapse of psychosis appears.

Psychosis in Parkinson's disease

Psychosis in Parkinson's disease (PD) is a fairly common and vexing problem. Although it can occur at any stage of the illness, it is a particularly important issue for patients who are in the later stages of PD and have been chronically treated with anti-PD medications. The exact pathophysiology of PD-related psychosis remains a mystery. Neurochemical imbalances, sleep disturbances, and visual processing abnormalities in PD have been implicated in its pathogenesis. Treatment of psychotic symptoms should occur only after potential medical and environmental causes of delirium have been eliminated or addressed. Initial pharmacologic changes should include limiting the patient's anti-PD medications to those that are necessary to preserve motor function. Should that fail, an atypical antipsychotic agent is presently the treatment of choice. An emerging treatment option is the use of acetylcholinesterase inhibitors. This article reviews what is known about the epidemiology, risk factors, pathophysiology, and treatment of PD-related psychosis.

Prolactin levels in antipsychotic treatment of patients with schizophrenia carrying the DRD2*A1 allele

BACKGROUND

Hyperprolactinaemia induced by D(2) dopamine receptor antagonist antipsychotic medication can result in significant health problems.

AIMS

To examine the role of DRD2 polymorphism on prolactin levels in patients treated with antipsychotic medication.

METHOD

Antipsychotic drugs with different degrees of D(2) receptor binding were given to 144 patients with schizophrenia. Serum prolactin levels were obtained and Taq1A DRD2 alleles were determined.

RESULTS

Prolactin levels increased across medication groups reflecting increasingly tight D(2) receptor binding (clozapine, olanzapine, typical antipsychotics and risperidone). In the combined medication group, patients with the DRD2(*)A1allele had 40% higher prolactin levels than patients without this allele. In patients treated with clozapine (the loosest D(2) receptor binding agent), patients with the DRD2(*)A1allele had prolactin levels twice those of patients without this allele.

CONCLUSIONS

Patients with the DRD2A1 allele receiving antipsychotic medications had higher prolactin levels and were overrepresented among those with hyperprolactinaemia, suggesting greater functional D(2) receptor binding in this group.

Contemporary management of prolactinomas

Prolactin-secreting pituitary adenomas--prolactinomas--are the most common type of functional pituitary tumor. Treatment of hyperprolactinemia is indicated because of the consequences of infertility, gonadal dysfunction, and osteoporosis. Making the correct diagnosis is important because the first line of therapy is medical management with dopamine agonists. Medical therapy is effective in normalizing prolactin levels in more than 90% of patients, but longterm treatment may be required in some patients. Transsphenoidal surgery is usually indicated in those patients in whom medical therapy fails or cannot be tolerated, or in patients who harbor microprolactinomas. In experienced hands, a hormonal and oncological cure can be achieved in more than 90% of patients after transsphenoidal removal of microprolactinomas with minimal risks. Thus, surgery may be an option for microprolactinomas in a young patient who desires restoration of fertility and avoidance of long-term medical therapy. The authors review the diagnosis and management of prolactinomas, including medical therapy, surgical therapy, and stereotactic radiosurgery.

Prolactin levels and erectile function in patients treated with risperidone

Treatment with risperidone is associated with prolactin (PRL) elevation, and PRL elevations are associated with erectile dysfunction (ED). We evaluated whether the PRL elevations caused by risperidone treatment of subjects with schizophrenia are associated with objective measures of erectile function. Subjects were hospitalized for 2 nights, and serum measurements of PRL, total testosterone, and free and weakly bound testosterone were performed in the morning and afternoon of each day. Risperidone levels, parent compound, and 9-hydroxy metabolite levels were drawn on the first day. Erectile function assessments, using the RigiScan, an instrument that measures nocturnal penile tumescence and rigidity, were performed on both nights. Consistent with previous reports, the correlation between total risperidone level and PRL was very high (r = 0.92, df = 12, P < 0.0001), but risperidone did not appear to affect either testosterone (r = 0.29, df = 5, P = 0.51) or free and weakly bound testosterone (r = -0.11, df = 10, P = 0.72). Contrary to expectations, PRL levels from the second night were positively correlated with erectile function (r = 0.68, df = 9, P = 0.022). Using objective measures, we were unable to confirm a detrimental association between PRL levels and male erectile function. These results are tentative given the small sample.

Hyperprolactinaemia and antipsychotic therapy in schizophrenia

Prolactin is a polypeptide hormone that exists as a number of isoforms and is involved in a multitude of physiological processes. Prolactin secretion is promoted by various physiological stimuli and pathological processes and is inhibited by the action of dopamine on the lactotroph cells of the hypothalamus. Hyperprolactinaemia, an elevation of prolactin levels above the norm, is a physiological occurrence and is not of concern (including sexual dysfunction and decreased bone mineral density). Treatment of hyperprolactinaemia is usually confined to the removal of the primary cause of the disease, but several dopamine agonists have been investigated. Hyperprolactinaemia is also a side-effect of the conventional, and some of the second-generation, antipsychotics used in the treatment of schizophrenia. These agents rely on their dopamine antagonistic properties to provide their antipsychotic effects. However, this also removes the brake on prolactin secretion, leading to hyperprolactinaemia. While antipsychotic use has been linked to certain hyperprolactinaemia-related side-effects (sexual dysfunction), its link to others (decreased bone mineral density) has proved more controversial. The association of symptoms with antipsychotic use is further complicated by the fact that patients with schizophrenia can suffer from some of these symptoms because of the disease itself. In managing antipsychotic-induced hyperprolactinaemia, the initial step is to exclude other causes of hyperprolactinaemia while monitoring the occurrence of adverse effects. The physician should also engage in close consultation with the patient with regard to the benefits of the antipsychotic medication and the impact of any adverse effects. A regular risk-benefit discussion will allow the clinician to achieve optimal outcomes in each case.

Rationale for current therapies in Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder that affects an estimated 1 million people in the US and tens of millions worldwide. Medication therapy has made significant advances and improvements especially over the last 10 years. A number of new treatments and new strategies have emerged and the quality of life for the average sufferer has improved. This review will describe the rationale and strategies for current medical therapies in PD, with special emphasis on the use of antipsychotic agents. Levodopa remains the most efficacious medication for the management of PD. Long-term use of levodopa, however, is associated with the development of motor fluctuations including dyskinesia. Trials with dopamine agonists have demonstrated a delay in the onset of dyskinesia with the use of this therapy. There is also active, ongoing investigation to determine whether a neuroprotective effect may be present with agonist therapy. Anticholinergics have been successfully used to treat tremor as well as sialorrhoea and urinary urgency. Catechol-O-methyltransferase inhibitors increase 'on time', decrease 'off time,' and improve motor scores. Continuous stimulation of dopamine receptors may decrease the fluctations observed with pulsatile delivery of anti-Parkinsonian medications, but this will require more study. Monoamine oxidase-B inhibitors, specifically selegiline, may provide symptomatic improvement; the question as to whether a neuroprotective benefit is present remains unanswered. Amantadine has demonstrated both symptomatic benefit and dyskinesia benefit in some patients. Selective dopamine blockers such as clozaril and quetiapine, have been shown to be effective in the treatment of psychosis. This class of medications is particularly useful as an adjunctive to levodopa and dopamine agonists. Doses of dopaminergic drugs can be escalated to treat Parkinsonian symptoms, whereas selective dopamine blockers can be added to block psychosis. Old management strategies required a reduction in dopaminergic therapy and therefore worsened Parkinsonian symptoms. Even though there have been great advances in the medical options for symptomatic management of PD, there are still many unmet needs for this patient population.

From chlorpromazine to clozapine--antipsychotic adverse effects and the clinician's dilemma

The pharmacotherapy of schizophrenia remains an ongoing challenge for researchers and clinicians alike. Current medications remain suboptimal to effectively treat this illness despite the recent surge of what are considered to be better antipsychotics: the atypicals. The atypicals cause fewer extrapyramidal symptoms and tardive dyskinesia, but there is growing concern regarding the significant long-term metabolic and cardiac adverse effects of these novel antipsychotics. There are differences among the atypicals in their propensity to produce these adverse effects, and clinicians should weigh the risk-benefit ratio for each drug with each individual patient. Diabetes, heart disease, obesity, and unhealthy lifestyle choices are on the rise in the general population, and individuals with chronic schizophrenia are even more at risk. The dilemma clinicians face in trying to avoid the neurological morbidity of the typicals (extrapyramidal side effects and tardive dyskinesia) is the risk of consequently exposing patients to both the morbidity and potential mortality of the atypicals (cardiovascular, endocrine, and metabolic adverse effects). The importance of baseline investigations and monitoring at regular intervals as well as identification of patients at risk for obesity, diabetes, and cardiovascular morbidity has become crucial. Informed decision making is essential for successful antipsychotic pharmacotherapy. For a condition, which often necessitates long-term pharmacotherapy, the importance of prevention and (or) minimization of morbidity and mortality related to adverse effects of such pharmacotherapy cannot be understated.

Long-term treatment goals: enhancing healthy outcomes

The long-term management of schizophrenia with a goal of functional rehabilitation remains an enormous challenge to clinicians despite improvements in drug therapy, psychosocial treatments, and family and community interventions. The goals of long-term therapy are to preserve the gains made during acute treatment, prevent symptom exacerbation, enhance psychosocial functioning, and improve quality of life. Schizophrenia is an illness that disrupts broad areas of mental function, including thought, cognition, affect, and motor performance. The new antipsychotics should aid physicians in meeting higher treatment goals for persons with schizophrenia. These agents combine high efficacy with improved tolerability, mainly through a low liability for extrapyramidal symptoms and probably improve cognitive affect. Recent studies have demonstrated efficacy of these new antipsychotics in improving psychopathology and symptoms and in preventing relapse during long-term use. These drugs are likely to provide physicians with an increasingly viable option in the long-term treatment and rehabilitation of patients with schizophrenia.

Factors in antipsychotic drug selection: tolerability considerations

With the widespread use of atypical antipsychotics over the past several years, adverse metabolic effects have emerged as the most serious medical consequences of pharmacotherapy with some of these agents. Initially, weight gain and obesity were observed (especially with clozapine and olanzapine), but subsequently, type 2 diabetes and dyslipidemia became apparent as well. Further, many reports suggest that sudden and severe (occasionally fatal) diabetes ketoacidosis (DKA) can emerge during treatment with some atypical antipsychotics, even in the absence of adiposity. A marked increase of serum lipids (especially triglycerides) has also been reported, to varying degrees, with different atypicals. This article reviews the data regarding metabolic dysfunction in patients with psychosis (schizophrenia and bipolar disorder). Populations with psychosis have a 2-3-fold higher prevalence of diabetes even before treatment with any antipsychotics, suggesting a possible genetic linkage or comorbidity; this was confirmed with glucose regulation studies in schizophrenia and mania. The induction of type 2 diabetes with atypicals has further increased the prevalence of noninsulin-dependent diabetes from about 6% to 8% to 11% to 15% according to recent studies, and even higher rates of subclinical hyperglycemia. Serious weight gain (eg, 26-29 lbs after 1 year of clozapine or olanzapine treatment) is an important risk factor, but sudden DKA has now been reported in patients with minimal weight gain, suggesting alternative mechanisms, such as insulin resistance, as a direct effect of some atypicals. Psychiatrists can reduce the risk of metabolic disorders in schizophrenia and bipolar disorder by avoiding the use of certain atypicals as first-line treatment in patients with a personal or family history of diabetes, obesity, and hyperlipidemias. Regulatory agencies in some countries have already taken action in this regard.

Objective and subjective efficacy as well as tolerability of olanzapine in the acute treatment of 120 patients with schizophrenia spectrum disorders

The aim of the present study was to evaluate the objective and subjective efficacy as well as tolerability of olanzapine in acute treatment of schizophrenia spectrum disorders under naturalistic non-selective conditions. Inpatients with schizophrenia spectrum disorders, consecutively admitted over an 18-month period, treated with olanzapine, were included. Diagnoses were made according to ICD-10 criteria based on repeated clinical assessments. Efficacy and tolerability of olanzapine were assessed at baseline and at the end of inpatient acute treatment including Positive and Negative Symptom Scale (PANSS), Clinical Global Impression, subjective assessments, UKU and biological investigations. One hundred and twenty non-selected patients who met ICD-10 criteria for schizophrenia (73%), schizophreniform disorder (14%) or schizoaffective disorder (13%) were treated with olanzapine 15.3+/-5.2 mg/day. Baseline severity (PANSS total mean score 102.2) was higher compared to various admittance studies (PANSS total mean score 86-90). In 32% of patients (n=38), olanzapine treatment was discontinued, mainly because of inefficacy for positive (89%, n=34) and/or negative (95%, n=36) symptoms and/or because of adverse events (37%, n=14). Response rates as improvement in PANSS total score (after > or =3 weeks of treatment) of > or =20%, 30% or 40% were 68%, 55% and 35%, respectively. Response rates in post-hoc defined treatment resistant patients were not significantly different from non-refractory patients. Sedation (26%) was the most common side-effect, followed by weight gain (22%). With regards to subjective efficacy, 30% of the patients were not satisfied with the efficacy of olanzapine, while only 6% of the patients reported a not satisfying subjective tolerability. According to duration of olanzapine treatment, the results for patients, who remained in hospital, revealed a faster increase of weight compared to admittance studies (7 kg in 14 weeks versus 7 kg in 38 weeks). Olanzapine has been found to be effective and tolerable, also under naturalistic acute treatment conditions. Compared to previous double-blind admittance studies, patients had a higher severity of illness at entry and a lower > or =40% PANSS total score response rate. By contrast to previous results, mean dose of olanzapine was similar for multiple- and first-episode patients, and weight gain was more severe. The results underline the need of Phase IV studies for the assessment of clinical antipsychotic efficacy and tolerability.

Hyperprolactinemia and schizophrenia: mechanisms and clinical aspects

The association between elevated prolactin levels and conventional antipsychotics is well-established. The novel antipsychotic, risperidone, has also been shown to elevate prolactin levels. Patients undergoing treatment with these medications are at high risk for developing hyperprolactinemia, which is associated with decreased bone mineral density, osteoporosis, menstrual disruptions and infertility, galactorrhea, breast cancer, cardiovascular disorders, and sexual impairment. Patients treated with conventional antipsychotics and risperidone should be routinely screened for hyperprolactinemia, and monitored for known sequelae. Optimally, patients with hyperprolactinemia secondary to antipsychotic drug treatment should be switched to a prolactin-sparing antipsychotic. This review will briefly highlight the regulation and function of prolactin secretion, discuss clinical effects of antipsychotic-induced hyperprolactinemia, and suggest a course of treatment.

Pharmacodynamics of ziprasidone in children and adolescents: impact on dopamine transmission

OBJECTIVE

Ziprasidone is an atypical antipsychotic with a high ratio of 5-HT(2A) to D(2) receptor antagonism. It is also an agonist at 5-HT(1A), which has been shown in rats to increase dopamine in prefrontal cortex. The objective of this study was to probe the dopamine agonist and antagonist pharmacodynamic properties of ziprasidone in youth.

METHOD

A single-dose, open-label study was conducted in 24 youths, 7 to 16 years of age, with Tourette syndrome or chronic tic disorder. Ziprasidone oral suspension (40 mg/mL) was given to achieve 0.2 to 0.3 mg/kg. Patients were subsequently assessed for serum ziprasidone, serum prolactin, and eye blink rates.

RESULTS

Serum ziprasidone peaked 4 hours postdose. Prolactin (baseline mean 7.2 ng/mL, 95% confidence interval [CI] 5.2-9.2) peaked at 4 hours (mean 27.5 ng/mL, 95% CI 22.6-32.3). Eyeblink rates per 5 minutes (baseline mean 60, 95% CI 42-79) peaked at 6 hours (mean 74, 95% CI 52-96).

CONCLUSIONS

Ziprasidone acutely blocks dopamine transmission, as indicated by increased prolactin levels, and, in a delayed fashion, appears to stimulate dopaminergic transmission, as indicated by the increase in spontaneous eye blinks. The mechanism of dopaminergic stimulation is presumed to be indirect, via 5-HT(1A) agonism.

Pharmacotherapy of first-episode psychosis

Early intervention in psychosis has attracted more attention in the last few years. The treatment of this phase of the disorders requires a specific and adapted approach. The issue of engaging the patient is so critical that it influences not only the choice of medication, but also the context and the way in which it is administered. In the case of a first admission, patients should be observed for 24-48 h without any antipsychotic treatment, in order to clarify the diagnosis and exclude the possibility that symptoms are caused by acute intoxication with illicit substances, for example. The diagnosis is often difficult and unstable. A dimensional, rather than a categorical approach, is usually more likely to be adopted. In recent years, atypical antipsychotics have become the most frequently used first-line treatment. They are less likely to cause secondary negative symptoms, cognitive impairments and dysphoria. They also appear to influence the course of depression and hostility/aggression better than conventional neuroleptics, have possibly mood-stabilising properties and, subjectively, are often better accepted by patients. On the risk side, prevalence of acute extrapyramidal side effects and possibly tardive dyskinesia are lower, compared to the older neuroleptics. Although, the risk for short-term weight gain, cardiovascular, and especially hyperglycaemic complications are somewhat higher for some of these antipsychotics. Finally, the dose should be adapted as it has been shown that patients presenting a first psychotic episode respond to a lower dose of antipsychotic. This article focuses on the pharmacotherapy of first-episode psychosis, on the basis of a computerised and a manual search for articles dealing with antipsychotic treatment of these patients. Findings are discussed and combined in clinical guidelines for first-episode affective and non-affective psychosis, for patients with incomplete recovery or treatment resistance, for cases of emergency and for side effects associated with antipsychotic treatment.

Hyperprolactinemia in response to antipsychotic drugs: characterization across comparative clinical trials

BACKGROUND

Atypical antipsychotic drugs for the treatment of schizophrenia provide effective treatment of psychotic symptoms with a safety profile superior to conventional antipsychotic medications. Neuroendocrine abnormalities in patients with schizophrenia, such as chronic hyperprolactinemia, may now potentially be minimized by the use of newer prolactin-sparing antipsychotic drugs. A discrimination of prolactin-sparing versus prolactin-elevating antipsychotic drugs may provide the clinician with treatment choices in order to avoid or mitigate hyperprolactinemia-associated morbidity.

METHODS

Results from five clinical trials were used to characterize factors that may influence antipsychotic drug effects on levels of serum prolactin. Factors investigated included drug treatment, gender, time course, potential for reduction or reversibility, and age.

RESULTS

Factors that influenced the risk of hyperprolactinemia included gender, with females appearing to be more sensitive than males, and drug treatment, with risperidone and conventional antipsychotic agents increasing prolactin more than olanzapine. Patients of all ages demonstrated sensitivity to increased prolactin. Furthermore, patients with hyperprolactinemia sustained the effect over time. Hyperprolactinemia reversed when patients were switched to a prolactin-sparing antipsychotic medication.

CONCLUSION

Effects of antipsychotic medications on serum prolactin are multi-factorial. Evidence for sexual, reproductive, and general medical consequences of antipsychotic-induced hyperprolactinemia is developing, and identifying antipsychotic drugs with a favorable prolactin profile would be important in mitigating these consequences. Most notably for women, atypical or novel antipsychotic drugs with a prolactin-sparing profile may offer effective clinical treatment with preservation of physiological hormonal function.

Understanding the new and evolving profile of adverse drug effects in schizophrenia

This article has reviewed the emerging side-effect profiles of second-generation antipsychotic medications. Although these medications have favorable extrapyramidal side-effect profiles, clinicians must be aware of their propensity to cause weight gain, glucose and lipid abnormalities, and cardiac and sexual side effects. If clinicians are proactive about warning patients about these side effects and appropriately monitoring them, further morbidity and mortality may be prevented in this patient population. Initial choices of medication should be made based on the relative side-effect profiles in light of a particular patient's medical status. In the future, new treatments may be developed, with even fewer side effects.

Antipsychotic-induced hyperprolactinaemia in women: pathophysiology, severity and consequences. Selective literature review

BACKGROUND

Hyperprolactinaemia has for decades been an inevitable and neglected side-effect of antipsychotic medication. The recent introduction of prolactin-sparing antipsychotic agents makes a re-examination of this problem timely.

AIMS

To review the literature on antipsychotic-induced hyperprolactinaemia and its consequences.

METHOD

A search was made of the Medline database (1966-2002) for key articles, supplemented by cross-referencing.

RESULTS

During antipsychotic treatment prolactin concentrations can rise to ten times normal levels or above, and existing data indicate that 17-78% of female patients have amenorrhoea with or without galactorrhoea. Survey data, however, suggest that clinicians underestimate the prevalence of these conditions. Long-term consequences of antipsychotic-related hypo-oestrogenism require further research but are likely to include premature bone loss.

CONCLUSIONS

Antipsychotic-induced hyperprolactinaemia should become a focus of interest in the drug treatment of psychiatric patients.

Atypical antipsychotics in Parkinson-sensitive populations

Drug-induced iatrogenic hallucinations and psychosis occur in about 30% of Parkinson's disease (PD) patients and are the single most important precipitant for nursing home placement, which carries a grave prognosis. In addition, parkinsonism is a frequent accompaniment to the more common dementing syndromes, Alzheimer's disease (AD), vascular dementia, and dementia with Lewy bodies (DLB). The five most recent antipsychotic drugs approved by the Food and Drug Administration in the United States have been marketed as "atypical" antipsychotics (AA) due to their relative freedom from extrapyramidal symptoms when used in schizophrenia patients. The use of these newer antipsychotic drugs in PD and other parkinson-sensitive populations represents the most stringent test to their freedom from motor side effects. To date, clozapine, risperidone, olanzapine, and quetiapine have been studied in parkinson-vulnerable populations. This article reviews the data and highlights the differences that these four drugs have on motor function. It also emphasizes the challenges in evaluating the available data on the motor effects of AA, especially on the non-PD elderly and cognitively impaired population. Suggestions are made for future research to improve the interpretability of these studies.

Resolution of risperidone-induced hyperprolactinemia with substitution of quetiapine

OBJECTIVE

To report a case of risperidone-induced hyperprolactinemia that was successfully managed with quetiapine.

CASE SUMMARY

A 30-year-old white woman with schizoaffective disorder, depressive type, and comorbid alcohol and cocaine abuse was treated successfully for her psychotic symptoms with risperidone until she developed adverse effects consistent with hyperprolactinemia. This was confirmed by laboratory blood tests, as her prolactin level was 186.9 ng/mL (normal for nonpregnant women 2.8-29.2). The woman had experienced similar effects in the past, which had led to noncompliance and subsequent psychotic relapse. Normalization of prolactin levels and associated adverse effects were achieved upon switching to quetiapine. No psychotic symptoms reoccurred.

DISCUSSION

Dopamine type 2 (D(2)) receptor blockade in the mesolimbic tract is thought to mediate the therapeutic effects of antipsychotics. This action in the tuberoinfundibular system produces prolactin level elevation. Risperidone has a relatively higher affinity for the D(2) receptor in comparison with other atypical antipsychotics, which may explain why it is associated with a higher incidence of hyperprolactinemia. Quetiapine, which has one of the lowest D(2) receptor affinities, is not known to increase prolactin levels to any significant degree. This pharmacologic property allows quetiapine to be a reasonable treatment option for patients who develop risperidone-induced hyperprolactinemia.

CONCLUSIONS

Quetiapine may be a suitable substitute when a patient taking risperidone develops hyperprolactinemia.

In vitro and in vivo pharmacological profile of 4-(4-fluorobenzylidene)-1-[2-[5-(4-fluorophenyl)-1H-pyrazol-4-yl] ethyl] piperidine (NRA0161)

Atypical antipsychotic properties of 4-(4-fluorobenzylidene)-1-[2-[5-(4-fluorophenyl)-1H-pyrazol-4-yl]ethyl] piperidine (NRA0161) were investigated by in vitro receptor affinities, in vivo receptor occupancies and findings were compared with those of risperidone and haloperidol in rodent behavioral studies. In in vitro receptor binding studies, NRA0161 has a high affinity for human cloned dopamine D(4) and 5-HT(2A) receptor with Ki values of 1.00 and 2.52 nM, respectively. NRA0161 had a relatively high affinity for the alpha(1) adrenoceptor (Ki; 10.44 nM) and a low affinity for the dopamine D(2) receptor (Ki; 95.80 nM). In in vivo receptor binding studies, NRA0161 highly occupied the 5-HT(2A) receptor in rat frontal cortex. In contrast, NRA0161 did not occupy the striatal D(2) receptor. In behavioral studies, NRA0161, risperidone and haloperidol antagonized the locomotor hyperactivity in mice, as induced by methamphetamine (MAP). At a higher dosage, NRA0161, risperidone and haloperidol dose-dependently antagonized the MAP-induced stereotyped behavior in mice and NRA0161 dose-dependently and significantly induced catalepsy in rats. The ED(50) value in inhibiting the MAP-induced locomotor hyperactivity was 30 times lower than that inhibiting the MAP-induced stereotyped behavior and 50 times lower than that which induced catalepsy. These findings suggest that NRA0161 may have atypical antipsychotic activities yet without producing extrapyramidal side effects.

Antipsychotics: impact on prolactin levels

Hyperprolactinaemia has been associated with a variety of side effects including amenorrhoea, galactorrhoea, sexual dysfunction, breast engorgement and osteoporosis. Since the mid-1970s, the impact of antipsychotics on human prolactin (hPrl) levels has been investigated. Baseline levels of hPrl were found to be similar in healthy controls and patients who were diagnosed as having schizophrenia. Short-term acute studies done after single parenteral or oral doses of phenothiazines found rapid two- to tenfold increases in hPrl. Similar increases were found in longer term studies that reported increases of three times in both men and women after 3 days that doubled again after several weeks of treatment. A study of longer term injectable fluphenazine enanthate found that elevation induced by a single injection lasted up to 28 days. The same results with significant increases have been reported with the butyrophenone, haloperidol. Substantial increases are found after single injections (up to nine times) and after weeks of treatment (up to three times sustained). Thus, early literature believed that there might be an association between these induced changes and response to therapy. However, prolactin is secreted by the anterior pituitary and is under inhibitory control of dopamine released from the tuberoinfundibular neurones. Thus, increases in prolactin are due to antipsychotic impact on tuberoinfundibular tract, one of four dopamine-related tracts. With the application of clozapine and other atypical antipsychotics, it was found that medications can successfully treat psychosis without increasing hPrl. In fact, early single-dose trails found clozapine to reduce hPrl by 16%. Later studies replicated this result and also found that up to 6 weeks of administration led to reductions in hPrl of up to 80%. Risperidone, however, has been found to persistently elevate hPrl in studies, despite its impact on other receptor sites. Olanzapine, quetiapine and ziprasidone have all been found to have little effect or produce decreases in hPrl. Most recently, aripiprazole, in early studies, appears to produce significant reductions in hPrl while maintaining therapeutic efficacy for psychosis.

The differential effects of atypical antipsychotics on prolactin elevation are explained by their differential blood-brain disposition: a pharmacological analysis in rats

All atypical antipsychotics avoid extrapyramidal side-effects yet differ in their propensity to cause other side-effects, like prolactin elevation. We proposed that the atypical antipsychotics with a propensity for prolactin elevation would show a higher pituitary versus striatal D2 receptor occupancy. To investigate this hypothesis, we tested four atypical antipsychotics, two that are commonly associated with prolactin elevation (amisulpride and risperidone) and two that are less frequently associated (quetiapine and olanzapine). In particular, we calculated their ED(50) values to increase plasma prolactin and block peripheral pituitary D2 receptors to their ED(50) values to antagonize apomorphine-induced stereotypy and occupy central striatal D2 receptors. All antipsychotics dose dependently increased prolactin levels and antagonized apomorphine-induced stereotypy. However, the central to peripheral potency (ED(50) for apomorphine antagonism to ED(50) for prolactin elevation) differed remarkably across these drugs: amisulpride (21764), risperidone (14), quetiapine (10), and olanzapine (1.7). Compounds displaying a higher peripheral potency brought about higher prolactin levels for a given level of functional central antagonism. This dissociation between central and peripheral effects was explained by the differential occupancy of D2 receptors in the striatum versus in the pituitary [ratio of striatal/pituitary ED(50) values (milligram per kilogram) for D2 occupancy): amisulpride (17/0.026 = 654), risperidone (0.89/0.081 = 14), quetiapine (24/4.1 = 6), olanzapine (0.30/0.43 = 0.7). These results indicate that dissociation between central and peripheral D2 receptor occupancy is a major determinant of the degree of prolactin elevation observed at therapeutic doses.

Pharmacological treatment of psychotic agitation

The presentation of agitated psychotic patients to psychiatric emergency services is a common occurrence. The traditionally accepted treatment for such patients involves the use of a typical antipsychotic, generally haloperidol. More recently benzodiazepines, such as lorazepam, have been used in combination with antipsychotics due to their sedative properties and relatively benign adverse effect profiles. Standard clinical protocol at many institutions involves the intramuscular administration of 5 to 10mg of haloperidol and 1 to 2mg of lorazepam. Atypical antipsychotics have gained acceptance as first-line treatments for psychotic disorders. These drugs are seen as an improvement over traditional antipsychotics because of their increased efficacy and reduced extrapyramidal effects. The utility of atypical antipsychotics in the emergency setting has been relatively unexplored because slow titration schedules or dose-limiting adverse effects for some members of the class have made this form of treatment impractical. However, the recent availability of oral liquid and rapidly dissolving tablet preparations of some atypical agents has provided useful alternatives in some cases. Nevertheless, for many patients a parenteral drug is the only desirable or feasible treatment option. Intramuscular preparations of the atypical antipsychotics olanzapine and ziprasidone have been developed, and are close to launch in the US. The availability of a rapid-acting intramuscular preparation of an atypical antipsychotic could represent a significant advancement in the treatment of agitation associated with psychosis.

Risperidone-induced increase in serum prolactin is correlated with positive symptom improvement in chronic schizophrenia

The elevation in serum prolactin (PRL) concentration in schizophrenic patients treated with typical antipsychotic drugs is well documented. Recently, increased prolactin levels have been reported in patients taking risperidone. The purpose of this study was to explore the effect of the atypical antipsychotic drug risperidone on serum prolactin, and to investigate the relationship between the change in PRL and the therapeutic outcome. In this study, 30 male inpatients with a diagnosis of chronic schizophrenia (DSM-III-R) were assigned to 12 weeks of treatment with risperidone after a 2-week washout period. The risperidone dose was fixed at 6 mg/day. Clinical efficacy was determined using the Positive and Negative Syndrome Scale (PANSS). Serum PRL was assayed in serum by radioimmunometric assay in schizophrenic patients before and after 12-week treatment, as compared to 30 age-matched normal male subjects. The results showed that risperidone treatment significantly increased the serum PRL. A significant and positive relationship between the change in PRL at pre- and post-treatment and the reduction rate of PANSS positive subscore was observed. Risperidone treatment significantly increased the serum PRL levels of schizophrenic patients. There was a close relationship between the improvement in positive symptoms and the change of serum PRL level before and after risperidone treatment. The serum PRL levels at baseline could be used to predict the responses of schizophrenic patients to risperidone.

Olanzapine: a review of its use in the treatment of bipolar I disorder

Olanzapine, a thienobenzodiazepine derivative, is a psychotropic agent that has shown efficacy in the treatment of patients with bipolar I disorder. Olanzapine has a multireceptorial binding profile including a greater affinity for serotonin 5-HT(2A) than for dopamine D(2) receptors. Olanzapine 5 to 20 mg/day demonstrated significantly greater antimanic efficacy than placebo in two double-blind, randomised 3- or 4-week trials of patients with bipolar I disorder of either manic or mixed episodes, with or without psychotic features. Additionally, in one of these trials, improvements in cognitive function and hostility were superior with olanzapine. In cohorts of severely depressed and rapid cycling patients, improvements in manic and depressive symptoms and in manic symptoms only, were superior with olanzapine compared with placebo. Significant improvements from baseline in symptoms of mania, depression, cognitive functioning and hostility were seen with olanzapine in a 49-week extension phase study. In double-blind trials, olanzapine 10 mg/day appeared to have similar antimanic efficacy to oral lithium 400mg twice daily in the treatment of patients with pure mania (4-week small study). In patients with acute manic or mixed episodes olanzapine 5 to 20 mg/day appeared to be more effective than oral valproate semisodium (divalproex sodium) 500 to 2500 mg/day (3-week study) and at least as effective as oral haloperidol 3 to 15 mg/day (12-week study). Preliminary results from a large 6-week placebo-controlled study suggest that olanzapine 5 to 20 mg/day in combination with mood stabilisers (lithium or valproate semisodium) provides effective augmentation of antimanic treatment of patients with bipolar I disorder, with benefits seen in the first week. Adverse events reported significantly more often with olanzapine than with placebo were somnolence, dry mouth, dizziness and bodyweight gain, and in comparison with valproate semisodium were somnolence, dry mouth, increased appetite and bodyweight gain. Olanzapine was generally well tolerated with no clinically relevant abnormalities in laboratory tests, vital signs or electrocardiogram results.

CONCLUSION

Olanzapine demonstrated superior efficacy compared with placebo in the short-term treatment of patients with bipolar I disorder with manic or mixed episodes, with or without psychotic features, and was generally well tolerated. According to preliminary data the antimanic efficacy of olanzapine appears similar to that of haloperidol and better than that of valproate semisodium in patients with bipolar I disorder experiencing a manic or mixed episode; among nonpsychotic patients with manic or mixed episodes olanzapine appears to be superior to haloperidol. Available data support the choice of olanzapine as an option in the short-term management of mania in patients with bipolar I disorder with manic or mixed episodes, with or without psychotic features.

In vitro cytokine secretion in individuals with schizophrenia: results, confounding factors, and implications for further research

The present paper reviews the results of all publications on in vitro cytokine secretion in patients with schizophrenia, as published by March 2001. The authors supply easy to read tables with respect to the individual cytokines and soluble cytokine receptors investigated, the in vitro methodology used, characterization of the patient samples, and the results on cytokine secretion as stated in these studies. Inconsistent results, e.g., regarding in vitro secretion of IL-2 with 11/18 studies finding decreased secretion, 5/18 finding no change, and 2/18 finding increases, cannot systematically be correlated with any methodological procedures nor any diagnostic subtypes, per se. However, factors such as medication and cigarette smoking are likely to play a role. The authors suggest that more hypothesis-driven research, together with more carefully designed studies, as well as better communication between basic or animal researchers and clinicians might help to answer the question of whether there are meaningful peripheral changes in the immune system related to schizophrenia.

Dramatic worsening of type 2 diabetes mellitus due to olanzapine after 3 years of therapy

Olanzapine, a serotonin-dopamine-receptor antagonist, is an atypical antipsychotic agent used to treat schizophrenia and other psychotic disorders. It is preferred over older antipsychotics because of its relatively low frequency of sedation, orthostatic hypotension, extrapyramidal symptoms, and anticholinergic side effects. A 45-year-old man with well-controlled type 2 diabetes mellitus experienced an abrupt worsening of his diabetes after 3 years of olanzapine therapy His hemoglobin A1c (HbA1c) level rose from a baseline of 5.9-6.2% to 12.5%. Discontinuation of olanzapine by means of a 3-month taper resulted in a reduction in HbA1c to pretreatment levels. Although cases of olanzapine-induced hyperglycemia have been documented in the literature, this complication has not been reported in a patient maintained on therapy for this duration. Clinicians should be aware of this possible complication in patients receiving long-term olanzapine therapy.