Long-term effects of the substituted benzamide derivative amisulpride on baseline and stimulated prolactin levels

Interaction of amisulpride with GLUT1 at the blood-brain barrier. Relevance to Alzheimer's disease

Blood-brain barrier (BBB) dysfunction may be involved in the increased sensitivity of Alzheimer's disease (AD) patients to antipsychotics, including amisulpride. Studies indicate that antipsychotics interact with facilitated glucose transporters (GLUT), including GLUT1, and that GLUT1 BBB expression decreases in AD. We tested the hypotheses that amisulpride (charge: +1) interacts with GLUT1, and that BBB transport of amisulpride is compromised in AD. GLUT1 substrates, GLUT1 inhibitors and GLUT-interacting antipsychotics were identified by literature review and their physicochemical characteristics summarised. Interactions between amisulpride and GLUT1 were studied using in silico approaches and the human cerebral endothelial cell line, hCMEC/D3. Brain distribution of [3H]amisulpride was determined using in situ perfusion in wild type (WT) and 5xFamilial AD (5xFAD) mice. With transmission electron microscopy (TEM) we investigated brain capillary degeneration in WT mice, 5xFAD mice and human samples. Western blots determined BBB transporter expression in mouse and human. Literature review revealed that, although D-glucose has no charge, charged molecules can interact with GLUT1. GLUT1 substrates are smaller (184.95±6.45g/mol) than inhibitors (325.50±14.40g/mol) and GLUT-interacting antipsychotics (369.38±16.04). Molecular docking showed beta-D-glucose (free energy binding: -15.39kcal/mol) and amisulpride (-29.04kcal/mol) interact with GLUT1. Amisulpride did not affect [14C]D-glucose hCMEC/D3 accumulation. [3H]amisulpride uptake into the brain (except supernatant) of 5xFAD mice compared to WT remained unchanged. TEM revealed brain capillary degeneration in human AD. There was no difference in GLUT1 or P-glycoprotein BBB expression between WT and 5xFAD mice. In contrast, caudate P-glycoprotein, but not GLUT1, expression was decreased in human AD capillaries versus controls. This study provides new details about the BBB transport of amisulpride, evidence that amisulpride interacts with GLUT1 and that BBB transporter expression is altered in AD. This suggests that antipsychotics could potentially exacerbate the cerebral hypometabolism in AD. Further research into the mechanism of amisulpride transport by GLUT1 is important for improving antipsychotics safety.

Psychotropics and Male Reproduction

Psychotropic drugs, including antidepressants, antipsychotics, and anticonvulsants, all have negative effects on sexual function and semen quality. These adverse events vary among men and are less pronounced for some medications, allowing their effects to be managed to some extent. Use of specific serotonin reuptake inhibitors (SSRIs) is prevalent in men of reproductive age; and application to treat premature ejaculation increases the number of young men on SSRI therapy. Oxidative damage to sperm can result from prolonged residence in the male reproductive tract. The increase in ejaculatory latency seen with SSRIs likely underlies some of their negative effects on semen quality, including higher sperm DNA fragmentation, seen in all SSRIs evaluated thus far. These medications increase prolactin (PRL) levels in some men, and this is often credited with inhibitory effects on male reproduction; however, testosterone levels are generally normal, reducing the likelihood of direct HPG axis inhibition by PRL. The tricyclic antidepressants have also been shown to increase PRL levels in some studies but not in others. The exception is the tricyclic antidepressant clomipramine, which profoundly increases PRL levels and may depress semen quality. Other antidepressants modulating synaptic levels of serotonin, norepinephrine, and/or dopamine may have toxicity similar to SSRIs, but most have not been evaluated. In limited studies, norepinephrine-dopamine reuptake inhibitors (NDRIs) and serotonin agonist/reuptake inhibitors (SARIs) have had minimal effects on PRL levels and on sexual side effects. Antipsychotic medications increase PRL, decrease testosterone, and increase sexual side effects, including ejaculatory dysfunction. The greatest evidence is for chlorpromazine, haloperidol, reserpine, risperidone, and thioridazine, with less effects seen with aripiprazole and clozapine. Remarkably few studies have looked at antipsychotic effects on semen quality, and this is an important knowledge gap in reproductive pharmacology. Lithium increases PRL and LH levels and decreases testosterone although this is informed by few studies. The anticonvulsants, many used for other indications, generally decrease free or bioavailable testosterone with variable effects on the other reproductive hormones. Valproate, carbamazepine, oxcarbazepine, and levetiracetam decrease semen quality; other anticonvulsants have not been investigated for this adverse reaction. Studies are required evaluating endpoints of pregnancy and offspring health for psychotropic medications.

Add-on effects of a low-dose aripiprazole in resolving hyperprolactinemia induced by risperidone or paliperidone

This study investigated the effects of a low-dose aripiprazole adjunctive treatment for risperidone- or paliperidone-induced hyperprolactinemia in Han Chinese women with schizophrenia. After 4 weeks of risperidone or paliperidone treatment, 60 out of 66 patients improved significantly and experienced hyperprolactinemia. They were randomly assigned to the treatment group (aripiprazole adjunctive treatment) (n=30) or control group (non-adjunctive treatment) (n=30). The dosage of risperidone and paliperidone were maintained; and aripiprazole was maintained at 5mg/day during the 8-week study period. The prolactin levels at the end of the 8th week were significantly lower in the treatment group than in the control group. The estradiol level correlated negatively with serum prolactin level both in the treatment group and the control group at the end of the 8th week and the 4th week respectively. The Positive and Negative Syndrome Scale score improved significantly during the 8-week study period in both groups. The incidence of treatment-emergent adverse event was similar in two groups. Low-dose aripiprazole adjunctive treatment is effective in relieving risperidone- and paliperidone-induced hyperprolactinemia in female schizophrenic patients without increasing adverse event.

Catechol-O-methyltransferase gene variants may associate with negative symptom response and plasma concentrations of prolactin in schizophrenia after amisulpride treatment

Catechol-O-methyltransferase (COMT) enzyme is involved in the pathogenesis of psychotic symptoms and may be associated with a therapeutic response to antipsychotic drugs. The aim of this study was to examine the relationship between COMT variants, plasma prolactin level, and the therapeutic effectiveness of amisulpride treatment in patients with schizophrenia. A 12-week naturalistic study of amisulpride treatment was carried out in 185 Han Chinese patients with schizophrenia. The patients were screened for 14 single-nucleotide polymorphisms of the COMT gene. The Positive and Negative Syndrome Scale (PANSS) was used to assess the improvement of psychopathological symptoms from the baseline to the end point in each subject. For better presentation of time-course changes in response status, a mixed model for repeated-measures (MMRM) analysis of symptom improvement during the 12-week treatment period was conducted. The change in plasma prolactin level after amisulpride treatment was also examined (n=51). No significant differences in the genotype frequencies of the COMT variants investigated were observed between responders and non-responders. Moreover, an MMRM analysis of psychopathological symptom improvement during the 12-week treatment course showed that it depended significantly on COMT variants (rs4680, rs4633, and rs6267), particularly regarding changes in negative symptoms. The increase in plasma prolactin levels observed was influenced by the COMT rs4680 variant and was positively correlated with a reduction in PANSS negative scores. Our results suggest that variation of the COMT gene is associated with treatment response regarding negative symptoms and prolactin changes after amisulpride treatment in patients with schizophrenia.

Flupenthixol decanoate (depot) for schizophrenia or other similar psychotic disorders

BACKGROUND

Long-acting depot injections of drugs such as flupenthixol decanoate are extensively used as a means of long-term maintenance treatment for schizophrenia.

OBJECTIVES

To evaluate the effects of flupenthixol decanoate in comparison with placebo, oral antipsychotics and other depot neuroleptic preparations for people with schizophrenia and other severe mental illnesses, in terms of clinical, social and economic outcomes.

SEARCH METHODS

We identified relevant trials by searching the Cochrane Schizophrenia Group Trials Register in March 2009 and then for this update version, a search was run in April 2013. The register is based on regular searches of CINAHL, EMBASE, MEDLINE and PsycINFO. References of all identified studies were inspected for further trials. We contacted relevant pharmaceutical companies, drug approval agencies and authors of trials for additional information.

SELECTION CRITERIA

All randomised controlled trials that focused on people with schizophrenia or other similar psychotic disorders where flupenthixol decanoate had been compared with placebo or other antipsychotic drugs were included. All clinically relevant outcomes were sought.

DATA COLLECTION AND ANALYSIS

Review authors independently selected studies, assessed trial quality and extracted data. For dichotomous data we estimated risk ratios (RR) with 95% confidence intervals (CI) using a fixed-effect model. Analysis was by intention-to-treat. We summated normal continuous data using mean difference (MD), and 95% CIs using a fixed-effect model. We presented scale data only for those tools that had attained prespecified levels of quality. Using Grading of Recommendations Assessment, Development and Evaluation (GRADE) we created 'Summary of findings tables and assessed risk of bias for included studies.

MAIN RESULTS

The review currently includes 15 randomised controlled trials with 626 participants. No trials compared flupenthixol decanoate with placebo.One small study compared flupenthixol decanoate with an oral antipsychotic (penfluridol). Only two outcomes were reported with this single study, and it demonstrated no clear differences between the two preparations as regards leaving the study early (n = 60, 1 RCT, RR 3.00, CI 0.33 to 27.23,very low quality evidence) and requiring anticholinergic medication (1 RCT, n = 60, RR 1.19, CI 0.77 to 1.83, very low quality evidence).Ten studies in total compared flupenthixol decanoate with other depot preparations, though not all studies reported on all outcomes of interest. There were no significant differences between depots for outcomes such as relapse at medium term (n = 221, 5 RCTs, RR 1.30, CI 0.87 to 1.93, low quality evidence), and no clinical improvement at short term (n = 36, 1 RCT, RR 0.67, CI 0.36 to 1.23, low quality evidence). There was no difference in numbers of participants leaving the study early at short/medium term (n = 161, 4 RCTs, RR 1.23, CI 0.76 to 1.99, low quality evidence) nor with numbers of people requiring anticholinergic medication at short/medium term (n = 102, 3 RCTs, RR 1.38, CI 0.75 to 2.25, low quality evidence).Three studies in total compared high doses (100 to 200 mg) of flupenthixol decanoate with the standard doses (˜40mg) per injection. Two trials found relapse at medium term (n = 18, 1 RCT, RR 1.00, CI 0.27 to 3.69, low quality evidence) to be similar between the groups. However people receiving a high dose had slightly more favourable medium term mental state results on the Brief Psychiatric Rating Scale (BPRS) (n = 18, 1 RCT, MD -10.44, CI -18.70 to -2.18, low quality evidence). There was also no significant difference in the use of anticholinergic medications to deal with side effects at short term (2 RCTs n = 47, RR 1.12, CI 0.83 to 1.52 very low quality evidence). One trial comparing a very low dose of flupenthixol decanoate (˜6 mg) with a low dose (˜9 mg) per injection reported no difference in relapse rates (n = 59, 1 RCT, RR 0.34, CI 0.10 to 1.15, low quality evidence).

AUTHORS' CONCLUSIONS

In the current state of evidence, there is nothing to choose between flupenthixol decanoate and other depot antipsychotics. From the data reported in clinical trials, it would be understandable to offer standard dose rather than the high dose depot flupenthixol as there is no difference in relapse. However, data reported are of low or very low quality and this review highlights the need for large, well-designed and reported randomised clinical trials to address the effects of flupenthixol decanoate.

Drug-induced hypo- and hyperprolactinemia: mechanisms, clinical and therapeutic consequences

INTRODUCTION

The altered profiles of prolactin secretion in the anterior hypophysis, generated by pathological, pharmacological or toxicological causes, have special consequences on multiple functions in both genders.

AREAS COVERED

This selective review presents the main mechanisms controlling prolactin secretion, focusing on the interplay of various neurotransmitters or xenobiotics, but also on the role of psychic or posttraumatic stress. A detailed analysis of several pharmacotherapeutic groups with hyperprolactinemic effects emphasize on the relevance of the pharmacokinetic/pharmacodynamic mechanisms and the clinical significance of the long term administration.

EXPERT OPINION

Accurate monitoring and evaluation of the hyperprolactinemia induced by xenobiotics is strongly recommended. The typical antipsychotics and some of the atypical agents (amisulpride, risperidone, paliperidone), as well as some antidepressants, antihypertensives and prokinetics, are the most important groups inducing hyperprolactinemia. The hyperprolactinemic effects are correlated with their affinity for dopamine D2 receptors, their blood-brain barrier penetration and, implicitly, the requested dose for adequate occupancy of cerebral D2 receptors. Consequently, integration of available pharmacokinetic and pharmacodynamic data supports the idea of therapeutic switch to non-hyperprolactinemic agents (especially aripiprazole) or their association, for an optimal management of antipsychotic-induced hyperprolactinemia. Possible alternative strategies for counteracting the xenobiotics-induced hyperprolactinemia are also mentioned.

The role of dopamine D(3) receptors in antipsychotic activity and cognitive functions

Dopamine D(3) receptors have a pre- and postsynaptic localization in brain stem nuclei, limbic parts of the striatum, and cortex. Their widespread influence on dopamine release, on dopaminergic function, and on several other neurotransmitters makes them attractive targets for therapeutic intervention. The signaling pathways of D(3) receptors are distinct from those of other members of the D(2)-like receptor family. There is increasing evidence that D(3) receptors can form heteromers with dopamine D(1), D(2), and probably other G-protein-coupled receptors. The functional consequences remain to be characterized in more detail but might open new interesting pharmacological insight and opportunities. In terms of behavioral function, D(3) receptors are involved in cognitive, social, and motor functions, as well as in filtering and sensitization processes. Although the role of D(3) receptor blockade for alleviating positive symptoms is still unsettled, selective D(3) receptor antagonism has therapeutic features for schizophrenia and beyond as demonstrated by several animal models: improved cognitive function, emotional processing, executive function, flexibility, and social behavior. D(3) receptor antagonism seems to contribute to atypicality of clinically used antipsychotics by reducing extrapyramidal motor symptoms; has no direct influence on prolactin release; and does not cause anhedonia, weight gain, or metabolic dysfunctions. Unfortunately, clinical data with new, selective D(3) antagonists are still incomplete; their cognitive effects have only been communicated in part. In vitro, virtually all clinically used antipsychotics are not D(2)-selective but also have affinity for D(3) receptors. The exact D(3) receptor occupancies achieved in patients, particularly in cortical areas, are largely unknown, mainly because only nonselective or agonist PET tracers are currently available. It is unlikely that a degree of D(3) receptor antagonism optimal for antipsychotic and cognitive function can be achieved with existing antipsychotics. Therefore, selective D(3) antagonism represents a promising mechanism still to be fully exploited for the treatment of schizophrenia, cognitive deficits in schizophrenia, and comorbid conditions such as substance abuse.

A double-blind, randomized, placebo-controlled study with JNJ-37822681, a novel, highly selective, fast dissociating D₂ receptor antagonist in the treatment of acute exacerbation of schizophrenia

JNJ-37822681 is a novel, highly selective dopamine D₂ receptor antagonist characterized by a rapid dissociation rate from the dopamine D₂ receptor. This profile was hypothesized to confer antipsychotic efficacy and improved tolerability. In this 12-week study, the efficacy and safety of JNJ-37822681 were evaluated in patients with an acute exacerbation of schizophrenia, randomly assigned (1:1:1:1:1) to JNJ-37822681 (10-, 20- or 30-mg bid), olanzapine (15 mg once-daily), or placebo (for 6 weeks followed by olanzapine for 6 weeks). Of 498 randomized patients, 298 (60%) completed the study. All JNJ-37822681 dose groups and the olanzapine group showed significantly greater reduction in PANSS total score from baseline to week 6 versus placebo (all p-values < 0.001). Least-squares adjusted mean changes from baseline to week 6 in PANSS total score were: -6.4 (placebo); -18.4 (10 mg JNJ-37822681), -17.7 (20 mg JNJ-37822681), -20.0 (30 mg JNJ-37822681) and -22.9 (olanzapine). All JNJ-37822681 groups showed significant improvement versus placebo from baseline to week 6 in the PANSS subscales, Marder factors, Clinical Global Impression of Severity, and in the Subjective Well-Being on Neuroleptics scale (all p-values < 0.05). The most common treatment-emergent adverse events with JNJ-37822681 were insomnia (17%) and akathisia (13%). Incidences of extrapyramidal symptoms were dose-related and were comparable for JNJ-37822681 10 mg bid and olanzapine groups. All JNJ-37822681 dose groups showed lesser weight gain compared with olanzapine. The efficacy and tolerability profile of the JNJ-37822681 10 mg bid was consistent with the study hypothesis.

World Federation of Societies of Biological Psychiatry (WFSBP) Guidelines for Biological Treatment of Schizophrenia, part 1: update 2012 on the acute treatment of schizophrenia and the management of treatment resistance

These updated guidelines are based on a first edition of the World Federation of Societies of Biological Psychiatry Guidelines for Biological Treatment of Schizophrenia published in 2005. For this 2012 revision, all available publications pertaining to the biological treatment of schizophrenia were reviewed systematically to allow for an evidence-based update. These guidelines provide evidence-based practice recommendations that are clinically and scientifically meaningful and these guidelines are intended to be used by all physicians diagnosing and treating people suffering from schizophrenia. Based on the first version of these guidelines, a systematic review of the MEDLINE/PUBMED database and the Cochrane Library, in addition to data extraction from national treatment guidelines, has been performed for this update. The identified literature was evaluated with respect to the strength of evidence for its efficacy and then categorised into six levels of evidence (A-F; Bandelow et al. 2008b, World J Biol Psychiatry 9:242). This first part of the updated guidelines covers the general descriptions of antipsychotics and their side effects, the biological treatment of acute schizophrenia and the management of treatment-resistant schizophrenia.

Risk of osteoporosis and fracture incidence in patients on antipsychotic medication

INTRODUCTION

In patients suffering from schizophrenia and bipolar disorder, antipsychotics are the mainstay of treatment worldwide. By blocking D(2) brain mesolimbic receptors, antipsychotics are believed to reduce and control psychotic experiences, but recent evidence has suggested that they may also have adverse effects on bone mineral architecture and fracture incidence.

AREAS COVERED

This study reviews current literature surrounding the use of antipsychotics and their effects on bone homeostasis. The primary medical search engines used for the study are Ovid MEDLINE (1950 - April 2010), EMBASE (1988 - April 2010) and PsychINFO (1987 - April 2010) databases.

EXPERT OPINION

Typical antipsychotics, in addition to the atypical antipsychotics risperidone and amisulpride, have been shown to increase serum prolactin levels in in vivo human studies. Results from animal and human in vitro and in vivo studies have demonstrated that high concentrations of prolactin have been shown to adversely affect bone cell metabolism and accelerate the rate bone mineral density loss, thereby increasing fracture risk. Increasing awareness of the side effect profile of antipsychotic medications on bone metabolism may prompt clinicians to screen patients at high risk of antipsychotic-induced osteoporosis and provide treatment, which may reduce the incidence of potentially avoidable fractures.

Hyperprolactinemia associated with psychotropics--a review

INTRODUCTION

Different classes of psychotropics can cause hyperprolactinemia to varying degrees. Among antipsychotics, typical agents and risperidone are the most frequent and significant offenders. In this review we discuss the pathophysiology, offending medications, assessment and management of hyperprolactinemia.

METHODS

We did a literature review between 1976 and 2008 using PubMed, MEDLINE, PsychINFO and Cochrane database. Search terms used were prolactin, hyperprolactinemia, psychotropics, antipsychotics, typical antipsychotics, atypical antipsychotics, antidepressants and SSRIs.

RESULTS

Prolactin elevation is more common with antipsychotics than with other classes of drugs. Typical antipsychotics are more prone to cause hyperprolactinemia than atypical agents. Management options include discontinuation of offending medication, switching to another psychotropic, supplementing concurrent hormonal deficiencies and adding a dopamine agonist or aripiprazole.

CONCLUSION

Clinicians need to be alert about the potential for hyperprolactinemia and its manifestations with these medications. Prolactin levels need to be monitored and other causes of hyperprolactinemia ruled out in suspected cases.

[Differences between men and women in side effects of second-generation antipsychotics]

In this review we investigate whether sex differences exist for side effects of second-generation antipsychotics. Results are based on a MEDLINE search for the years 1974 through 2005. Even if pharmacokinetics differ between females and males, significantly higher plasma levels for women have been demonstrated only for olanzapine and clozapine. Hyperprolactinaemia is mainly induced by treatment with risperidone and amisulpride, and there is evidence for more pronounced prolactin levels in females. Most studies reviewed indicate that clozapine and olanzapine are associated with more body weight gain, once more especially in female patients. Furthermore, the few published studies indicate that metabolic syndrome is more frequent in females and there are likely no gender-specific differences between the new antipsychotic medications concerning frequency and degree of acute or chronic movement disturbance. The risk of QT prolongation with torsades de pointes arrhythmia is again higher in females. In conclusion, there is some evidence of sex differences in the side effects of second-generation antipsychotics. For better understanding of the basic mechanisms in sex differences, future studies with a primary focus on this topic are required. More specific data will help to determine how these differences shall affect clinical management.

Amisulpride-induced hyperprolactinemia is reversible following discontinuation

BACKGROUND

Although amisulpride is considered to be a prolactin-raising atypical antipsychotic drug, a limited number of studies have documented the extent of its prolactin-elevating properties. In the present study the effect of amisulpride on plasma levels of prolactin and the reversibility of this untoward side effect were investigated.

METHODS

17 patients with various diagnoses received amisulpride (50-800 mg/day) or a combination of amisulpride plus other medication as needed. Plasma prolactin was determined 26.7+/-9.4 days (range: 13-50 days) after initiation of treatment and in 3 cases after a much longer period, and 14-51 days following its withdrawal.

RESULTS

All patients on amisulpride had hyperprolactinemia (mean+/-S.D. prolactin levels: 62.5+/-33.0 ng/ml) with females exhibiting considerably higher prolactin levels than males. Following amisulpride discontinuation prolactin levels were significantly (p<000) reduced (mean+/-S.D. prolactin levels: 12.3+/-6.7 ng/ml). No significant correlation was detected between prolactin levels and either amisulpride dosage or duration of administration.

CONCLUSION

Amisulpride has a pronounced prolactin-elevating effect which appears to be independent of dosage and duration of administration. Hyperprolactinemia rapidly reverses following amisulpride discontinuation.

Comparison of pramipexole and amisulpride on alertness, autonomic and endocrine functions in healthy volunteers

RATIONALE

In a previous study in healthy volunteers, the anti-Parkinsonian drug pramipexole caused sedation and pupil dilatation, consistent with the stimulation of inhibitory D(2)/D(3) autoreceptors on the ventral tegmental area dopaminergic neurones. The sedation may be related to the removal of the dopaminergic excitation of the locus coeruleus (via the meso-coerulear pathway), whereas the pupil dilatation may be due to the removal of the dopaminergic excitation of the Edinger-Westphal nucleus (via a putative meso-pupillomotor pathway).

OBJECTIVES

We investigated the hypothesis that amisulpride, a D(2)/D(3) receptor antagonist, would have effects opposite to those of pramipexole on alertness, pupillary and endocrine functions.

MATERIALS AND METHODS

Pramipexole (0.5 mg), amisulpride (50 mg), and their combination were administered to 16 healthy males in a balanced, cross-over, double-blind design. Tests included measures of alertness (Pupillographic Sleepiness Test, critical flicker fusion frequency, visual analogue scales), pupillary functions (resting pupil diameter, light and darkness reflex responses), non-pupillary autonomic functions (heart rate, blood pressure, salivation, core temperature), and endocrine functions [blood concentrations of prolactin, growth hormone (GH) and thyroid stimulating hormone (TSH)]. Data were analysed by ANOVA.

RESULTS

Pramipexole reduced alertness and pupillary light reflex response amplitude, tended to reduce core temperature, reduced prolactin levels and increased GH levels. Amisulpride reduced pupil diameter, increased the amplitude of the light reflex response and prolactin and TSH levels.

CONCLUSIONS

The opposite effects of pramipexole and amisulpride on alertness, pupillary function and pituitary hormone levels are consistent with their interactions with inhibitory D(2)/D(3) receptors on VTA neurones and in the tuberoinfundibular system.

Antipsychotiques atypiques et dysfonction sexuelle : à propos de cinq cas associés à la rispéridone

LITERATURE FINDINGS

Sexual and reproductive function side effects of atypical antipsychotics are frequent, often underestimated and badly tolerated. They contribute to the 50% rate of non-compliance reported for treated patients. Prevalence of sexual dysfunction associated with atypical antipsychotic treatment is high, varying from 18 to 96%. Atypical antipsychotics aren't, as a group, much better than typical antipsychotics, and among them, risperidone seems to induce more and quetiapine less sexual dysfunction. Most atypicals are non-selective, and have actions on multiple central and peripheral receptors. Among these, dopaminergic blockade could have a direct - altering motivation (desire) and reward (orgasm) - and an indirect negative influence on sexuality. Actually, the secondary hyperprolactinemia induced by some antipsychotics (typical antipsychotics, risperidone and amisulpiride), is dose-dependent, more pronounced for female patients, and may have a detrimental effect on sexual function. It also may result in hypogonadism, particularly for female patients. The long-term consequences of this secondary hypogonadism are subject to debate but potentially severe. Furthermore, the blocking and/or modulating actions of atypical antipsychotics on adrenaline, serotonine, histamine or acetyl-choline receptors all have the potential to contribute to secondary sexual problems. The pharmacological profile of risperidone, characterized by a strong affinity for D2 and alpha1 receptors, correlates with his tendency to significantly elevate prolactin levels and to produce ejaculatory disturbances. FIVE CASE-REPORTS: We describe five case-reports of sexual or hormonal disturbances associated with risperidone treatment: two cases of ejaculatory disturbance, one case of galactorrhea and two cases of amenorrhea. Alberto and David are two young male schizophrenic patients, treated with risperidone, and complaining of a total absence of ejaculation despite a preserved orgasm. Many recent case-reports describe the occurrence of retrograde ejaculation associated with risperidone but the exact prevalence is unknown. Retrograde ejaculation is thought to be related to the strong adrenolytic activity of risperidone. Alberto refused his medication because the ejaculatory dysfunction was unbearable for him. A switch to haloperidol depot was eventually well tolerated, without any sexual complaints. His case emphasizes the importance of sexual function for self-esteem and how this may amplify the intolerance to side-effects. David is on depot-risperidone in a setting of a legally forced treatment. Though he - reluctantly - accepts his medication, this side effect exacerbates his pre-existing delusions, strongly focused on sexual themes. His case illustrates how intolerance to sexual side-effects may be amplified by nature of delusions. Mireille is a 58 year old psychotic female patient, whose 2 mg risperidone treatment produced a unilateral galactorrhea. This sign became problematic because potentially visible at a time when Mireille started an activity in a sheltered occupation in town. Lowering dosage of antipsychotic allowed disappearance of the problem. Subjective responses to galactorrhea have been reported to be highly individual. Apart being a potentially visible side-effect, it may be misinterpreted as evidence of pregnancy or of a tumoral process. The cases of Ermina and Denise illustrate two contrasted situations in terms of subjective tolerability of reproductive function side-effects. Both were pre-menopausal patients with hyperprolactinemia secondary to risperidone treatment, resulting in amenorrhea. This was unbearable for Ermina. A switch to olanzapine allowed, one month later, the menses to resume. For Denise, on the other hand, the amenorrhea was a positive event, freeing her of unpleasant menses.

DISCUSSION

Amenorrhea occurs in about 30% of pre-menopausal women treated with risperidone. It is a consequence of hyperprolactinemia, which, although often silent, is not devoid of potential negative consequences (ie increased risk of osteoporosis or neoplasia, worsening of psychopathology) (34). When hyperprolactinemia is symptomatic, lowering of the dose of the antipsychotic, or switching to a prolactin-sparing agent (olanzapine, quetiapine, aripiprazole and clozapine) is recommended. Before this, women with amenorrhea secondary to antipsychotic-induced hyperprolactinemia should be advised that menses may resume. Especially after long-standing amenorrhea they may assume being menopaused, hence may believe birth control measures are no longer required. The prevalence of antipsychotic-induced sexual and reproductive function side-effects is high. Clinicians should be aware of them, because they are often badly tolerated, are associated with a low satisfaction and may therefore result in low adherence with treatment. This implies for the clinician to overtly discuss with the patient of his sexuality and the potential negative impact of antipsychotic treatment on it. The recognition of these problems allows the searching together for a solution.

CONCLUSION

The described cases indicate that solving the problem is often possible, provided that individual preferences and subjective impact are taken in account. Antipsychotic treatment is often prescribed for very long periods. A better knowledge of - and attention to - the associated side effects, particularly on the sexual and reproductive functions, is necessary in order to reduce some potentially negative long-term effects and to improve the adherence to treatment of our patients.

The effects of amisulpride on five dimensions of psychopathology in patients with schizophrenia: a prospective open-label study

BACKGROUND

The efficacy of antipsychotics can be evaluated using the dimensional models of schizophrenic symptoms. The D2/D3-selective antagonist amisulpride has shown similar efficacy and tolerability to other atypical antipsychotics. The aim of the present study was to determine the efficacy of amisulpride on the dimensional model of schizophrenic symptoms and tolerability in latin schizophrenic patients.

METHOD

Eighty schizophrenic patients were enrolled and 70 completed a prospective open-label 3-month study with amisulpride. The schizophrenic symptoms, psychosocial functioning and side-effects were evaluated with standardized scales.

RESULTS

The patients showed significant improvement in the five dimensions evaluated. Amisulpride (median final dose 357.1 mg/d) was well-tolerated without treatment-emergent extrapyramidal side-effects.

CONCLUSION

Amisulpride showed efficacy on different psychopathological dimensions and was well tolerated, leading to consider this drug a first line choice for the treatment of schizophrenia.

Amisulpride augmentation of clozapine: an open non-randomized study in patients with schizophrenia partially responsive to clozapine

OBJECTIVE

Treatment options are very limited for individuals with schizophrenia resistant to clozapine. We tested the hypothesis that amisulpride augmentation would lead to an improvement in these patients.

METHOD

This was an open non-randomized study. Thirty-three patients with sub-optimal response to clozapine were commenced on amisulpride in addition to clozapine. Clinical status was evaluated at baseline, 3 and 6 months using the Positive And Negative Syndrome Scale (PANSS), Scale for the Assessment of Negative Symptoms (SANS), Global Assessment Scale (GAS), Calgary Depression Scale, Calgary Anxiety Scale and various side effect rating scales.

RESULTS

Twenty-eight subjects completed 6 months treatment on clozapine and amisulpride. There was a statistically significant improvement in the mean scores for PANSS, SANS and GAS at follow-up and no significant changes in side effect ratings.

CONCLUSION

Co-administration of amisulpride, in a group of patients partially or non-responsive to clozapine, may lead to a substantial improvement in positive and negative symptoms, without worsening the side effect burden.

Prolactinemia is uncoupled from central D2/D3 dopamine receptor occupancy in amisulpride treated patients

RATIONALE

Atypical antipsychotic drugs are classically associated with lower propensity to extrapyramidal symptoms (EPS) and hyperprolactinemia than typical antipsychotic drugs. It has not been clarified why some atypical antipsychotic drugs, such as amisulpride, induce prolactin plasma concentration (PRL) elevation, but little EPS. Previous studies have found an association between striatal D2/D3 receptor occupancy and PRL in typical antipsychotic treated patients suggesting that PRL is a marker of central D2/D3 receptors blockade.

OBJECTIVE

We have evaluated the relationship between PRL and central (striatum, temporal cortex and thalamus) D2/D3 receptor occupancy in amisulpride treated schizophrenic patients.

METHODS

Single photon emission tomography (SPET) and [123I]-epidepride were used to determine D2/D3 receptor occupancy in eight amisulpride treated patients. PRL was measured concurrently with the scans.

RESULTS

The mean PRL was 1166 (range 499-1892 mIU/l) for a mean amisulpride dose of 406 mg/day (range 150-600 mg/day). Amisulpride plasma concentration and central D2/D3 receptor occupancy were positively correlated (r=0.83-0.89, df=4, P<0.05). No significant correlations were observed between PRL and amisulpride (daily dose or plasma concentration, P>0.05), or between PRL and central D2/D3 receptor occupancy (P>0.05).

CONCLUSIONS

Our findings show that amisulpride-induced hyperprolactinemia is uncoupled from central D2/D3 receptor occupancy. Amisulpride has poor blood-brain barrier penetration and reaches much higher concentration at the pituitary, which is outside the blood-brain barrier. Higher D2/D3 receptor occupancy at the pituitary gland than at central regions is a possible explanation for amisulpride PRL elevation with low EPS. Further studies evaluating pituitary D2/D3 receptor occupancy in vivo are necessary to confirm this hypothesis.

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.