Ponatinib and STAT5 Inhibitor Pimozide Combined Synergistic Treatment Applications Potentially Overcome Drug Resistance via Regulating the Cytokine Expressional Network in Chronic Myeloid Leukemia Cells

Chronic myeloid leukemia (CML) is a clonal myeloproliferative hematological disease characterized by the chimeric breakpoint-cluster region/Abelson kinase1 (BCR::ABL1) oncoprotein; playing a pivotal role in CML molecular pathology, diagnosis, treatment, and possible resistance arising from the success and tolerance of tyrosine kinase inhibitor (TKI)-based therapy. The transcription factor STAT5 constitutive signaling, which is influenced by the cytokine signaling network, triggers BCR::ABL1-based CML pathogenesis and is also relevant to acquired TKI resistance. The unsuccessful therapeutic approaches targeting BCR::ABL1, in particular third-line therapy with ponatinib, still need to be further developed with alternative combination strategies to overcome drug resistance. As treatment with the STAT5 inhibitor pimozide in combination with ponatinib resulted in an efficient and synergistic therapeutic approach in TKI-resistant CML cells, this study focused on identifying the underlying amplification of ponatinib response mechanisms by determining different cytokine expression profiles in parental and ponatinib-resistant CML cells, in vitro. The results showed that expression of interleukin (IL) 1B, IL9, and IL12A-B was increased by 2-fold, while IL18 was downregulated by 2-fold in the ponatinib-resistant cells compared to sensitive ones. Importantly, ponatinib treatment upregulated the expression of 21 of the 23 interferon and IL genes in the ponatinib-resistant cells, while treatment with pimozide or a combination dose resulted in a reduction in the expression of 19 different cytokine genes, such as for example, inflammatory cytokines, IL1A-B and IL6 or cytokine genes associated with supporting tumor progression, leukemia stem cell growth or poor survival, such as IL3, IL8, IL9, IL10, IL12, or IL15. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis results showed that the genes were mainly enriched in the regulation of receptor signaling through the Janus kinase/signal transducer and activator of transcription pathway, cytokine-cytokine receptor interaction, and hematopoietic cell lineage. Protein-protein interaction analysis showed that IL2, IL6, IL15, IFNG, and others appeared in the top lists of pathways, indicating their high centrality and importance in the network. Therefore, pimozide could be a promising agent to support TKI therapies in ponatinib resistance. This research would help to clarify the role of cytokines in ponatinib resistance and advance the development of new therapeutics to utilize the STAT5 inhibitor pimozide in combination with TKIs.

STAT5 activation promotes progression and chemotherapy resistance in early T-cell precursor acute lymphoblastic leukemia

Interleukin-7 (IL-7) supports the growth and chemoresistance of T-cell acute lymphoblastic leukemia (T-ALL), particularly the early T-cell precursor subtype (ETP-ALL), which frequently has activating mutations of IL-7 signaling. Signal transducer and activator of transcription (STAT5) is an attractive therapeutic target because it is almost universally activated in ETP-ALL, even in the absence of mutations of upstream activators such as the IL-7 receptor (IL-7R), Janus kinase, and Fms-like tyrosine kinase 3 (FLT3). To examine the role of activated STAT5 in ETP-ALL, we have used a Lmo2-transgenic (Lmo2Tg) mouse model in which we can monitor chemoresistant preleukemia stem cells (pre-LSCs) and leukemia stem cells (LSCs) that drive T-ALL development and relapse following chemotherapy. Using IL-7R-deficient Lmo2Tg mice, we show that IL-7 signaling was not required for the formation of pre-LSCs but essential for their expansion and clonal evolution into LSCs to generate T-ALL. Activated STAT5B was sufficient for the development of T-ALL in IL-7R-deficient Lmo2Tg mice, indicating that inhibition of STAT5 is required to block the supportive signals provided by IL-7. To further understand the role of activated STAT5 in LSCs of ETP-ALL, we developed a new transgenic mouse that enables T-cell specific and doxycycline-inducible expression of the constitutively activated STAT5B1∗6 mutant. Expression of STAT5B1∗6 in T cells had no effect alone but promoted expansion and chemoresistance of LSCs in Lmo2Tg mice. Pharmacologic inhibition of STAT5 with pimozide-induced differentiation and loss of LSCs, while enhancing response to chemotherapy. Furthermore, pimozide significantly reduced leukemia burden in vivo and overcame chemoresistance of patient-derived ETP-ALL xenografts. Overall, our results demonstrate that STAT5 is an attractive therapeutic target for eradicating LSCs in ETP-ALL.

Discovery of a new candidate drug to overcome cabazitaxel-resistant gene signature in castration-resistant prostate cancer by in silico screening

BACKGROUND

The taxane cabazitaxel (CBZ) is a promising treatment for docetaxel-resistant castration-resistant prostate cancer (CRPC). However, the survival benefit with CBZ for patients with CRPC is limited. This study used screening tests for candidate drugs targeting CBZ-resistant-related gene expression and identified pimozide as a potential candidate for overcoming CBZ resistance in CRPC.

METHODS

We established CBZ-resistant cell lines, DU145CR and PC3CR by incubating DU145 cells and PC3 cells with gradually increasing concentrations of CBZ. We performed in silico drug screening for candidate drugs that could reprogram the gene expression signature of a CBZ-resistant prostate cancer cells using a Connectivity Map. The in vivo effect of the drug combination was tested in xenograft mice models.

RESULTS

We identified pimozide as a promising candidate drug for CBZ-resistant CRPC. Pimozide had a significant antitumor effect on DU145CR cells. Moreover, combination treatment with pimozide and CBZ had a synergic effect for DU145CR cells in vitro and in vivo. Microarray analysis identified AURKB and KIF20A as potential targets of pimozide in CBZ-resistant CRPC. DU145CR had significantly higher AURKB and KIF20A expression compared with a non-CBZ-resistant cell line. Inhibition of AURKB and KIF20A had an antitumor effect in DU145CR xenograft tumors. Higher expression of AURKB and KIF20A was a poor prognostic factor of TGCA prostate cancer cohort. CBZ-resistant prostate cancer tissues in our institution had higher AURKB and KIF20A expression.

CONCLUSIONS

Pimozide appears to be a promising drug to overcome CBZ resistance in CRPC by targeting AURKB and KIF20A.

Pimozide and pancreatic cancer in diabetic chorea: a case report

PURPOSE/AIM

Diabetic chorea is a rare movement disorder associated with diabetes mellitus. We report the case of a patient that benefited from pimozide and died of pancreatic cancer.

CASE REPORT

A 70-year-old woman presented with pollakiuria and involuntary movements of left limbs since three months. Laboratory tests revealed high serum levels of glycemia and glycated haemoglobin. She was admitted to internal medicine department and discharged one week later: insulin was administered with normalization of blood glucose levels and the involuntary movements gradually disappeared. Three weeks later she was admitted to neurological department due to the recurrence of the involuntary movements. Glycemia and other routine laboratory tests were normal. Neurological examination showed choreic movements involving left limbs. MRI showed a hyperintensity on T1- and T2-weighted sequences of right putamen and caudate nucleus head. Haloperidol was administered without improvement, it was successively substituted with tetrabenazine and the patient was discharged with an unvaried clinical picture. Two months later tetrabenazine was discontinued because of inefficacy and pimozide was started. The choreic movements considerably diminished after few days. Four months later, a pancreatic cancer was diagnosed and the patient died in the same month.

CONCLUSION

Clinical and radiological features were suggestive of diabetic chorea. Our patient benefited exclusively from pimozide, it could be reasonable to use pimozide in resistant form and also propose it as first choice treatment. Another important element is the diagnosis of pancreatic cancer some months after chorea onset: a causal link could exist.

The Respective Roles of CYP3A4 and CYP2D6 in the Metabolism of Pimozide to Established and Novel Metabolites

Pimozide is a dopamine receptor antagonist indicated for the treatment of Tourette syndrome. Prior in vitro studies characterized N-dealkylation of pimozide to 1,3-dihydro-1-(4-piperidinyl)-2H-benzimidazol-2-one (DHPBI) via CYP3A4 and, to a lesser extent, CYP1A2 as the only notable routes of pimozide biotransformation. However, drug-drug interactions between pimozide and CYP2D6 inhibitors and CYP2D6 genotype-dependent effects have since been observed. To reconcile these incongruities between the prior in vitro and in vivo studies, we characterized two novel pimozide metabolites: 5-hydroxypimozide and 6-hydroxypimozide. Notably, 5-hydroxypimozide was the major metabolite produced by recombinant CYP2D6 (Km ∼82 nM, V max ∼0.78 pmol/min per picomoles), and DHPBI was the major metabolite produced by recombinant CYP3A4 (apparent Km ∼1300 nM, V max ∼2.6 pmol/min per picomoles). Kinetics in pooled human liver microsomes (HLMs) for the 5-hydroxylation (Km ∼2200 nM, V max ∼59 pmol/min per milligram) and N-dealkylation (Km ∼3900 nM, V max ∼600 pmol/min per milligram) reactions were also determined. Collectively, formation of DHPBI, 5-hydroxypimozide, and 6-hydroxypimozide accounted for 90% of pimozide depleted in incubations of NADPH-supplemented pooled HLMs. Studies conducted in HLMs isolated from individual donors with specific cytochrome P450 isoform protein abundances determined via mass spectrometry revealed that 5-hydroxypimozide (r 2 = 0.94) and 6-hydroxypimozide (r 2 = 0.86) formation rates were correlated with CYP2D6 abundance, whereas the DHPBI formation rate (r 2 = 0.98) was correlated with CYP3A4 abundance. Furthermore, the HLMs differed with respect to their capacity to form 5-hydroxypimozide relative to DHPBI. Collectively, these data confirm a role for CYP2D6 in pimozide clearance via 5-hydroxylation and provide an explanation for a lack of involvement when only DHPBI formation was monitored in prior in vitro studies. SIGNIFICANCE STATEMENT: Current CYP2D6 genotype-guided dosing information in the pimozide label is discordant with available knowledge regarding the primary biotransformation pathways. Herein, we characterize the CYP2D6-dependent biotransformation of pimozide to previously unidentified metabolites. In human liver microsomes, formation rates for the novel metabolites and a previously identified metabolite were determined to be a function of CYP2D6 and CYP3A4 content, respectively. These findings provide a mechanistic basis for observations of CYP2D6 genotype-dependent pimozide clearance in vivo.

The antipsychotic drug pimozide inhibits IgE-mediated mast cell degranulation and migration

BACKGROUND

Mast cells (MCs) mediate a key role in allergic diseases. Detailed studies of how the neuroleptic drug pimozide affects MC activity are lacking. The aim of this study was to investigate pimozide inhibition of immunoglobulin E (IgE)-mediated MC activation and MC-mediated allergic responses.

METHOD

MCs were stimulated with anti-dinitrophenyl (DNP) IgE antibodies and DNP-horse serum albumin (HSA) antigen (Ag), and anti-allergic pimozide effects were detected by measuring β-hexosaminidase levels. Morphological changes were observed histologically. In vivo pimozide effects were assessed in passive cutaneous anaphylaxis (PCA) and ovalbumin (OVA)-sensitized active systemic anaphylaxis mouse (ASA) model experiments. Levels of phosphorylated (p-) SYK (spleen tyrosine kinase) and MAPKs (mitogen-activated protein kinases) were detected in western blots.

RESULTS

We found that pimozide inhibited MC degranulation, reduced MC release of β-hexosaminidase dose-dependently in activated RBL-2H3 (IC₅₀: 13.52 μM) and bone marrow derived MC (BMMC) (IC₅₀: 42.42 μM), and reduced MC morphological changes. The IgE/Ag-induced migration effect was suppressed by pimozide treatment dose-dependently. Pimozide down-regulated IgE/Ag-induced phosphorylation of SYK and MAPKs in activated MCs. Moreover, pimozide attenuated allergic reactions in PCA and ASA model mice, and decreased MC populations among splenic cells.

CONCLUSIONS

The antipsychotic drug pimozide can suppress IgE-mediated MC activation in vitro and in vivo and should be considered for repurposing to suppress MC-mediated diseases.

Non-antiepileptic drugs for trigeminal neuralgia

BACKGROUND

Trigeminal neuralgia was defined by the International Association for the Study of Pain as a sudden, usually unilateral, severe, brief, stabbing recurrent pain in the distribution of one or more branches of the fifth cranial nerve. Standard treatment is with anti-epileptic drugs. Non-antiepileptic drugs have been used in the management of trigeminal neuralgia since the 1970s. This is an update of a review first published in 2006 and previously updated in 2011.

OBJECTIVES

To systematically review the efficacy and tolerability of non-antiepileptic drugs for trigeminal neuralgia.

SEARCH METHODS

On 20 May 2013, for this updated review, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL (2013, Issue 4), MEDLINE (January 1966 to May 2013), EMBASE (January 1980 to May 2013), LILACS (January 1982 to May 2013) and the Chinese Biomedical Retrieval System (1978 to May 2013). We searched clinical trials registries for ongoing trials.

SELECTION CRITERIA

We included double-blind, randomised controlled trials in which the active drug was used either alone or in combination with other non-antiepileptic drugs for at least two weeks.

DATA COLLECTION AND ANALYSIS

Two authors decided which trials fitted the inclusion criteria and independently graded risk of bias. We assessed the quality of the evidence according to the GRADE criteria for this update.

MAIN RESULTS

In this 2013 update, we updated the searches, but identified only two new ongoing studies. The review includes four trials involving 139 participants. The primary outcome measure in each was pain relief. Three trials compared one of the oral non-antiepileptic drugs tizanidine, tocainide or pimozide with carbamazepine. The quality of evidence for all outcomes for which data were available was low. In a trial of tizanidine involving 12 participants (one dropped out due to unrelated disease), one of five participants treated with tizanidine and four of six treated with carbamazepine improved (risk ratio (RR) 0.30, 95% confidence interval (CI) 0.05 to 1.89). Few side effects were noted with tizanidine. For pimozide, there was evidence of greater efficacy than carbamazepine at six weeks. Up to 83% of participants reported adverse effects but these did not lead to withdrawal; the report did not provide comparable data for carbamazepine. Limited data meant that we could not assess the effects of tocainide; however, data from non-randomised studies (not included in this review) indicate that serious haematological adverse events can occur. A trial involving 47 participants compared 0.5% proparacaine hydrochloride eyedrops with placebo but did not show any significant benefits, again according to low-quality evidence. The report did not mention adverse events. The proparacaine trial was at low risk of bias; the other trials were at unclear risk of bias overall.

AUTHORS' CONCLUSIONS

There is low-quality evidence that the effect of tizanidine is not significantly different than that of carbamazepine in treating trigeminal neuralgia. Pimozide is more effective than carbamazepine, although the evidence is of low quality and the data did not allow comparison of adverse event rates. There is also low-quality evidence that 0.5% proparacaine hydrochloride eye drops have no benefit over placebo. Limitations in the data for tocainide prevent any conclusions being drawn. There is insufficient evidence from randomised controlled trials to show significant benefit from non-antiepileptic drugs in trigeminal neuralgia. More research is needed.

Pimozide for schizophrenia or related psychoses

BACKGROUND

Pimozide, formulated in the 1960s, continues to be marketed for the care of people with schizophrenia or related psychoses such as delusional disorder. It has been associated with cardiotoxicity and sudden unexplained death. Electrocardiogram monitoring is now required before and during use.

OBJECTIVES

To review the effects of pimozide for people with schizophrenia or related psychoses in comparison with placebo, no treatment or other antipsychotic medication.A secondary objective was to examine the effects of pimozide for people with delusional disorder.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Register (28 January 2013).

SELECTION CRITERIA

We sought all relevant randomised clinical trials (RCTs) comparing pimozide with other treatments.

DATA COLLECTION AND ANALYSIS

Working independently, we inspected citations, ordered papers and then re-inspected and assessed the quality of the studies and of extracted data. For homogeneous dichotomous data, we calculated the relative risk (RR), the 95% confidence interval (CI) and mean differences (MDs) for continuous data. We excluded data if loss to follow-up was greater than 50%. We assessed risk of bias for included studies and used GRADE to rate the quality of the evidence.

MAIN RESULTS

We included 32 studies in total: Among the five studies that compared pimozide versus placebo, only one study provided data for global state relapse, for which no difference between groups was noted at medium term (1 RCT n = 20, RR 0.22 CI 0.03 to 1.78, very low quality of evidence). None of the five studies provided data for no improvement or first-rank symptoms in mental state. Data for extrapyramidal symptoms demonstrate no difference between groups for Parkinsonism (rigidity) at short term (1 RCT, n = 19, RR 5.50 CI 0.30 to 101.28, very low quality of evidence) or at medium term (1 RCT n = 25, RR 1.33 CI 0.14 to 12.82, very low quality of evidence), or for Parkinsonism (tremor) at medium term (1 RCT n = 25, RR 1 CI 0.2 to 4.95, very low quality of evidence). No data were reported for quality of life at medium term.Of the 26 studies comparing pimozide versus any antipsychotic, seven studies provided data for global state relapse at medium term, for which no difference was noted (7 RCTs n = 227, RR 0.82 CI 0.57 to 1.17, moderate quality of evidence). Data from one study demonstrated no difference in mental state (no improvement) at medium term (1 RCT n = 23, RR 1.09 CI 0.08 to 15.41, very low quality evidence); another study demonstrated no difference in the presence of first-rank symptoms at medium term (1 RCT n = 44, RR 0.53 CI 0.25 to 1.11, low quality of evidence). Data for extrapyramidal symptoms demonstrate no difference between groups for Parkinsonism (rigidity) at short term (6 RCTs n = 186, RR 1.21 CI 0.71 to 2.05,low quality of evidence) or medium term (5 RCTs n = 219, RR 1.12 CI 0.24 to 5.25,low quality of evidence), or for Parkinsonism (tremor) at medium term (4 RCTs n = 174, RR 1.46 CI 0.68 to 3.11, very low quality of evidence). No data were reported for quality of life at medium term.In the one study that compared pimozide plus any antipsychotic versus the same antipsychotic, significantly fewer relapses were noted in the augmented pimozide group at medium term (1 RCT n = 69, RR 0.28 CI 0.15 to 0.50, low quality evidence). No data were reported for mental state outcomes or for extrapyramidal symptoms (EPS). Data were skewed for quality of life scores, which were not included in the meta-analysis but were presented separately.Two studies compared pimozide plus any antipsychotics versus antipsychotic plus placebo; neither study reported data for outcomes of interest, apart from Parkinsonism at medium term and quality of life using the Specific Level of Functioning scale (SLOF); however, data were skewed.Only one study compared pimozide plus any antipsychotic versus antipsychotics plus antipsychotic; no data were reported for global state and mental state outcomes of interest. Data were provided for Parkinsonism (rigidity and tremor) using the Extrapyramidal Symptom Rating Scale (ESRS); however, these data were skewed.

AUTHORS' CONCLUSIONS

Although shortcomings in the data are evident, enough overall consistency over different outcomes and time scales is present to confirm that pimozide is a drug with efficacy similar to that of other, more commonly used antipsychotic drugs such as chlorpromazine for people with schizophrenia. No data support or refute its use for those with delusional disorder.

Metabolic effects of aripiprazole and pimozide in children with Tourette syndrome

This study assessed the metabolic effects of aripiprazole and pimozide in pediatric Tourette syndrome, a neurodevelopmental condition characterized by multiple motor and phonic tics. Patients receiving aripiprazole (n = 25) or pimozide (n = 25) were compared with medication-free patients (n = 25). Body mass index, glycemia, triglyceridemia, and cholesterolemia were monitored at baseline and 12 and 24 months after commencing treatment. The aripiprazole group demonstrated significant increases in cholesterolemia. The pimozide group demonstrated significant increases in glycemia. Both groups demonstrated elevations in triglyceridemia not significantly different from those in unmedicated control subjects. The effect of aripiprazole on cholesterol was apparent after 12 months, but leveled off during year 2 of treatment. Longitudinal studies are required to evaluate the full extent of glycemic alterations with pimozide. Both agents appear relatively safe for use in pediatric Tourette syndrome. These findings will help guide medication selection in patients with specific medical vulnerabilities.

Non-antiepileptic drugs for trigeminal neuralgia

BACKGROUND

Non-antiepileptic drugs have been used in the management of trigeminal neuralgia since the 1970s.

OBJECTIVES

The objective was to systematically review the efficacy and tolerability of non-antiepileptic drugs for trigeminal neuralgia.

SEARCH STRATEGY

For this updated review we searched the Cochrane Neuromuscular Disease Group Specialized Register (30 April 2010). We also searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 2), MEDLINE (January 1966 to April 2010), EMBASE (January 1980 to April 2010), LILACS (January 1982 to April 2010) and the Chinese Biomedical Retrieval System (1978 to April 2010). We handsearched 10 Chinese journals.

SELECTION CRITERIA

We searched for double-blind randomized or quasi-randomized controlled trials in which the active drug was used for at least two weeks.

DATA COLLECTION AND ANALYSIS

Two authors decided which trials fitted the inclusion criteria and independently graded risk of bias.

MAIN RESULTS

Four trials involving 139 participants were included. The primary outcome measure in each was pain relief. Three trials with an unclear risk of bias compared one of the non-antiepileptic drugs tizanidine, tocainide or pimozide with carbamazepine. In a trial of tizanidine involving 12 participants (one dropped out due to unrelated disease) one of five treated with tizanidine and four of six treated with carbamazepine improved, risk ratio 0.30 (95% CI 0.05 to 1.89). Few side effects were noted with tizanidine. In a study involving 12 participants there was an improvement in mean pain scores with tocainide similar to that with carbamazepine, but significant side effects limited its use. In the pimozide study more participants improved on pimozide (48/48) than with carbamazepine (27/48) (risk ratio 1.76, 95% CI 1.37 to 2.26). Up to 83% of participants reported adverse effects but these did not lead to withdrawal from the study. A trial with low risk of bias involving 47 participants compared 0.5% proparacaine hydrochloride eyedrops with placebo but did not show any significant benefits or side effects.

AUTHORS' CONCLUSIONS

Of the four studies identified, one had low and three an unclear risk of bias. There is insufficient evidence from randomized controlled trials to show significant benefit from non-antiepileptic drugs in trigeminal neuralgia. More research is needed.

Aripiprazole as a viable alternative for treating delusions of parasitosis

Delusions of parasitosis (DOP) is a psychiatric disorder characterized by the fixed false belief that one is infested with parasites or other organisms. Historically, pimozide, a first-generation antipsychotic, has been the treatment of choice for DOP, although there is risk for serious adverse effects including extrapyramidal symptoms, QTc prolongation and tardive dyskinesia. Recently, there have been several reports describing the effectiveness of second-generation antipsychotics (SGAs), but these agents have their own unique adverse effects, specifically metabolic changes with olanzapine, sedation with quetiapine and hyperprolactinemia with risperidone. Aripiprazole is a novel, third-generation antipsychotic with comparable efficacy to SGAs, but a more favorable side effect profile. Successful treatment of DOP with aripiprazole has recently been described in the psychiatric and dermatologic literature. The authors present another report to support the use of aripiprazole as an efficacious and safe alternative for treating DOP.

Pimozide for tics in Tourette's syndrome

BACKGROUND

Neuroleptic drugs with potent D-2 receptor blocking properties have been the traditional treatment for tics caused by Tourette Syndrome. Pimozide is the most studied of these. Use of these medications is declining because of concerns about side effects, and new atypical neuroleptics are now available. The true benefit and risks associated with pimozide compared to other drugs is not known.

OBJECTIVES

To evaluate the efficacy and harms of pimozide in comparison to placebo or other medications in the treatment of tics in Tourette Syndrome.

SEARCH STRATEGY

We cross-referenced pimozide and its proprietary names with Tourette Syndrome and its derivations, as MeSH headings and as text words, and searched the Cochrane Movement Disorders Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 4), MEDLINE (1950-April 2007), and EMBASE (1980-April 2007). Reference lists of relevant articles were reviewed for additional trials.

SELECTION CRITERIA

All randomized, controlled, double blind studies comparing pimozide to placebo or other medications for the treatment of tics in Tourette Syndrome were considered for inclusion in this review. Both parallel group and crossover studies of children or adults, at any dose and for any duration, were included.

DATA COLLECTION AND ANALYSIS

Data was abstracted independently by two authors onto standardized forms and disagreements were resolved by discussion.

MAIN RESULTS

Six randomized controlled trials were included (total 162 participants, age range 7 to 53 years). Pimozide was compared with: placebo and haloperidol (two trials), placebo (one trial), haloperidol (one trial), and risperidone (two trials). Methodological quality was rated 'fair' for all studies. Studies used different outcome measurement scales for assessing tic severity and adverse effects. Significant clinical heterogeneity made meta-analysis inappropriate. Pimozide was superior to placebo in three studies, though it caused more side effects than placebo in one of these. Pimozide was inferior to haloperidol in one of three studies (the other two showed no significant difference between the drugs), which also showed significantly fewer side effects associated with pimozide. No significant differences between pimozide and risperidone were detected.

AUTHORS' CONCLUSIONS

Pimozide is an effective treatment for tics in Tourette Syndrome, though the number of trials comparing its effect to placebo and other drugs is limited. Trials of longer duration (minimum six months) are needed to investigate the longer-term effects of pimozide compared to atypical neuroleptics. Future trials should use the Yale Global Tic Severity Scale to assess the main outcome measure, and quantify adverse events with the Extrapyramidal Symptoms Rating Scale.

Levetiracetam in the treatment of antipsychotics-resistant Tourette syndrome

Levetiracetam, an anti-epileptic agent that enhances GABAergic neurotransmission, is one of the newest alternative treatments of Tourette syndrome (TS). We present the case of a 23-year-old female patient suffering from TS since the age of 7, who exhibited poor response to a variety of agents (haloperidol, pimozide, clonidine and various adjunctive agents) and had four hospitalizations during the previous 2 years due to the deterioration of her clinical state. On her last admission, in addition to clonidine 600 microg/day (already part of her regimen for the previous 4 years), levetiracetam was prescribed, up to 2000 mg/day, progressively titrated over a 3-week period. The patient presented a significant improvement on her TS symptomatology (the score on the Yale Global Tic Severity Scale dropped from 70 at admission, to 25 five weeks later, at discharge), which was preserved during the subsequent 4 months, without any serious side-effect.

Pimozide for schizophrenia or related psychoses

BACKGROUND

Pimozide, formulated in the 1960s, continues to be marketed for the care of people with schizophrenia or related psychoses such as delusional disorder. It has been associated with cardiotoxicity and sudden unexplained deaths. Electrocardiogram monitoring is now required before and during use.

OBJECTIVES

To assess the clinical effects of pimozide for people with schizophrenia, non-affective psychotic mental illness and delusional disorder.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Group's Register (July 2005).

SELECTION CRITERIA

We sought all relevant randomised clinical trials comparing pimozide with other treatments.

DATA COLLECTION AND ANALYSIS

Working independently, we inspected citations, ordered papers, and then re-inspected and quality assessed the studies and extracted data. For homogeneous dichotomous data, we calculated the relative risk (RR), 95% confidence interval (CI), and, where appropriate, the number needed to treat (NNT) and the number needed to harm (NNH), on an intention-to-treat basis. We calculated weighted mean differences (WMD) for continuous data. We excluded data if loss to follow-up was greater than 50%.

MAIN RESULTS

We found 35 relevant studies (total n=1348), all including people with schizophrenia but none with delusional disorder. 123 people were randomised to pimozide versus placebo. Data suggest that pimozide prevents relapse (2 RCTs, n=66, RR 0.45 CI 0.2 to 0.9, NNT 4 CI 3 to 22). Compared with typical antipsychotic drugs, pimozide has similar efficacy for outcomes of change in global functioning, mental state, relapse and leaving the study early. People allocated to pimozide did not have a higher mortality than those taking other antipsychotic drugs. Pimozide was more likely than typical antipsychotic drugs to cause tremor in the short-term (6 RCTs, n=192, RR 1.6 CI 1.1 to 2.3, NNH 6 CI 3 to 44) and lead to need for antiparkinsonian medication (4 RCTs, n=124, RR 1.8 CI 1.2 to 2.6, NNH 3 CI 2 to 5) than other drugs. In the medium-term, however, pimozide was less likely to cause sedation (5 RCTs, n=231, RR 0.6 CI 0.5 to 0.9, NNH 6 CI 4 to 16).

AUTHORS' CONCLUSIONS

Although there are shortcomings in the data, there is enough overall consistency over different outcomes and time scales to confirm that pimozide is a drug with similar efficacy to other more commonly used antipsychotic drugs such as chlorpromazine for people with schizophrenia. There are no data to support or refute its use for those with delusional disorder.

Sydenham's chorea: a clinical follow-up of 65 patients

Sydenham's chorea, the neurological manifestation of rheumatic fever, is the most common acquired chorea of childhood. In this retrospective study, the authors aim to present the clinical and laboratory findings of 65 Sydenham's chorea patients, followed up in a clinic over less than 7 years. The mean age at the onset of the symptoms was 11.7 +/- 2.6 years (range, 6-17 years). Of the patients, 63% were female and 37% were male (male/female: 1.7/1). Chorea was generalized in 78.5% of the patients, right hemichorea in 12.3%, and left hemichorea 9.2%. There was a history of rheumatic fever in 30.8% of the patients. Echocardiographic study showed cardiac valve involvement in 70.5% of 61 patients. Brain magnetic resonance imaging, which was performed on only 18 patients, was evaluated as normal in all. Electroencephalography was also performed on only 18 patients and showed abnormal waves in 50% of them. Pimozide was mostly the first choice of drug therapy. Nevertheless, drug therapy was not needed in 18.5% of the patients. The recovery period of the first attack of the chorea was 1 to 6 months in 51.7% of the patients. The recurrence rate was 37.9%. In conclusion, Sydenham's chorea is still an important health problem in Turkey with respect to its morbidity.

Treating delusional disorder: a comparison of cognitive-behavioural therapy and attention placebo control

OBJECTIVE

Cognitive-behavioural therapy (CBT) has proved effective in treating delusions, both in schizophrenia and delusional disorder (DD). Clinical trials of DD have mostly compared CBT with either treatment as usual, no treatment, or a wait-list control. This current study aimed to assess patients with DD who received CBT, compared with an attention placebo control (APC) group.

METHOD

Twenty-four individuals with DD were randomly allocated into either CBT or APC groups for a 24-week treatment period. Patients were diagnosed on the basis of structured clinical interviews for mental disorders and the Maudsley Assessment of Delusion Schedule (MADS).

RESULTS

Completers in both groups (n = 11 for CBT; n = 6 for APC) showed clinical improvement on the MADS dimensions of Strength of Conviction, Insight, Preoccupation, Systematization, Affect Relating to Belief, Belief Maintenance Factors, and Idiosyncrasy of Belief.

CONCLUSION

When compared with APC, CBT produced more impact on the MADS dimensions for Affect Relating to Belief, Strength of Conviction, and Positive Actions on Beliefs.

Effect of gabaergic, glutamatergic, antipsychotic and antidepressant drugs on pilocarpine-induced seizures and status epilepticus

This work was designed to study the influence of drugs during seizures and status epilepticus (SE) induced by pilocarpine and mortality in adult rats. Fluoxetine (10 and 20 mg/kg), NMDA (N-methyl-D-aspartate, 10 and 20 mg/kg), amitriptyline (25 and 50 mg/kg), ketamine (0.5 and 1.0 mg/kg), gabapentin (100 and 150 mg/kg) and pimozide (10 and 20 mg/kg) were administered intraperitoneally, 30 min prior to pilocarpine (400mg/kg, s.c.). The animals were observed (24h) to determine: number of peripheral cholinergic signs, tremors, stereotyped movements, seizures, SE, latency to first seizure and number of deaths after pilocarpine treatment. Fluoxetine, amitriptyline, NMDA, and pimozide had proconvulsant effects in both doses tested. Smaller and higher doses of these drugs no protected and increased pilocarpine-induced seizures and/or mortality. Gabapentin and ketamine protected against seizures and reduced the latency to first seizure. Thus, these results suggest that caution should be taken in the selection of pharmacotherapy and dosages for patients with epilepsy because of the possibility of potentiating convulsive process toxicity.

Non-antiepileptic drugs for trigeminal neuralgia

BACKGROUND

Non-antiepileptic drugs have been used in trigeminal neuralgia management since the 1970s.

OBJECTIVES

The objective was to review systematically the efficacy of non-antiepileptic drugs for trigeminal neuralgia.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Register, MEDLINE, EMBASE, and LILACS (all to August 2005) and the Chinese Biomedical Retrieval System, the database of the Chinese Cochrane Center (The Cochrane Library, Issue 1 2005), conference paper databases and checked bibliographies. We handsearched ten Chinese journals.

SELECTION CRITERIA

We searched for randomized or quasi-randomized controlled trials.

DATA COLLECTION AND ANALYSIS

Two authors decided which trials fitted the inclusion criteria and graded methodological quality independently.

MAIN RESULTS

Nine trials of different non-antiepileptic drugs involving 223 participants were included. Each trial investigated one non-antiepileptic drug. Two trials tested baclofen. In one, more people gained 50% reduction from baseline than with placebo (relative risk 15.00, 95% CI 0.97 to 231.84, P value = 0.05). In the other, slightly more participants on baclofen had a 75% reduction in attacks on the 10th day compared with carbamazepine (relative risk 2.38, 95% CI 0.83 to 6.85, P value = 0.11). One trial showed no significant difference in reduction in average daily frequency of attacks with L-Baclofen compared with racemic baclofen. Tizanidine was investigated in two trials. In one, the proportion of people with reduction in the average number of paroxysms per day increased with tizanidine compared with placebo (relative risk 8.00, 95% CI 1.21 to 52.69, P value = 0.03). In the other, one of five participants improved in visual analog scale score with tizanidine and four of six with carbamazepine (relative risk 0.30, 95% CI 0.05 to 1.89, P value = 0.20). One study showed that the improvement in mean values of pain scores with tocainide was similar to that of carbamazepine. In one study more participants improved during the pimozide than the carbamazepine period (relative risk 1.78, 95% CI 1.39 to 2.28). In one study, proparacaine hydrochloride 0.5% instillation into the eyes was not significantly different from placebo (relative risk 1.06, 95% CI 0.37 to 2.99, P value = 0.92). In another, there was moderate or marked improvement in seven of nine participants treated with clomipramine and three of nine with amitriptyline after a 12-week treatment (RR 2.33, 95% CI 0.87 to 6.27).

AUTHORS' CONCLUSIONS

There is insufficient evidence from randomized controlled trials to show significant benefit from non-antiepileptic drugs in trigeminal neuralgia. More research is needed.

Fetal exposure to pimozide: a case report

BACKGROUND

Pimozide is an antidopaminergic, antipsychotic drug. Exposure during human pregnancy has not been reported previously, and recommendations on its use are based on extrapolation from other antipsychotics with antidopaminergic activity.

CASE

A 26-year-old woman had Gilles de la Tourette syndrome and obsessive-compulsive disorder. It was not possible to discontinue pimozide during pregnancy, although the dosage was reduced to 1 mg daily. In addition, she was treated with 20 mg fluoxetine until gestational week 27. By request of the patient, elective cesarean section was scheduled for week 38. As a precaution, pimozide was withdrawn 2 weeks prior to the section. During this period the patient's symptoms severely intensified, and an emergency cesarean section had to be performed at 36 weeks. A healthy male infant weighing 2,448 g was delivered. Pediatric examination of the infant and electroencephalogram demonstrated no neurologic abnormalities. On day 4 both mother and infant were discharged.

CONCLUSION

This is the first published report on fetal exposure to pimozide.

Successful Treatment of Delusions of Parasitosis With Olanzapine

BACKGROUND

Delusional parasitosis is a rare disorder in which patients have a fixed, false belief of being infested with parasites. It is often accompanied by a refusal to seek psychiatric care. Delusions of parasitosis is classically treated with typical antipsychotic agents, the traditional dermatologic choice being pimozide. However, pimozide's adverse effect profile and the need for frequent electrocardiographic monitoring make such treatment less practical.

OBSERVATION

We describe 3 patients who were diagnosed as having delusional parasitosis that was successfully treated with a recently Food and Drug Administration-approved atypical antipsychotic agent, olanzapine (5 mg/d). Olanzapine has a more benign adverse effect profile than typical antipsychotic agents and eliminates the need for electrocardiographic monitoring. Olanzapine therapy has been associated with such adverse effects as sedation, hyperlipidemia, weight gain, and insulin resistance, all of which were infrequent in our patients.

CONCLUSION

Olanzapine is an atypical antipsychotic agent that can be used as a first-line agent in delusional parasitosis as a safer therapeutic option without a specialized monitoring regimen.

Delusion of oral parasitosis in a patient with major depressive disorder

Delusion of parasitosis is a rare condition in which the patient has a strong conviction that he or she is infested by small organisms. The condition may exist as an isolated phenomenon, or may occur in association with other psychiatric syndromes. We report a single case of a rare form of this phenomenon. A middle-aged woman who met forth edition of diagnostic and statistical manual of mental disorders criteria for major depressive disorder with psychotic features is described. She had delusions of oral parasitosis. She felt lizards and small organisms in her mouth. To the best of our knowledge, there has been only one previous report of delusions of oral parasitosis to date. We discuss the interesting aspects of this case.

Erotomania : epidemiology and management

Erotomania is generally classified as a delusional disorder in contemporary classification systems (DSM-IV and ICD-10). The incidence of erotomania is not known, but that of delusional disorder in general has been reported as approximately 15 cases per 100,000 of the population per year, with a female : male ratio of 3 : 1. Both primary and secondary types of erotomania have been identified, the latter being associated with evidence of an aetiologically significant organic or psychiatric condition. The aetiology of primary erotomania is not yet fully understood, but neuroimaging, genetic studies and findings from evolutionary psychopathology hold considerable promise for a deeper and broader understanding of this condition. The initial management of secondary erotomania focuses on treating the underlying organic or psychiatric illness. The management of primary and secondary erotomania involves a combination of pharmacological treatments, psychosocial interventions and risk management strategies. In the past, the antipsychotic medication pimozide was commonly used, at least in certain countries (such as the US and Canada), despite a paucity of systematic studies of its use in this disorder. In recent years, there have been reports of positive therapeutic outcomes with atypical antipsychotics (risperidone, clozapine), which, as a result of their improved tolerability over older agents such as pimozide, will hopefully enhance patient acceptability and, thereby, improve clinical outcome. Despite this advance, there is still a strong need for controlled clinical trials of therapeutic strategies for primary erotomania and related syndromes.

Placebo-controlled study of pimozide augmentation of fluoxetine in body dysmorphic disorder

OBJECTIVE

Although body dysmorphic disorder often responds to serotonin reuptake inhibitors (SRIs), most patients do not respond or respond only partially. However, placebo-controlled studies of augmentation of SRIs have not been done. Furthermore, although 40%-50% of patients are delusional, studies of antipsychotic medications have not been done.

METHOD

Twenty-eight patients with body dysmorphic disorder or its delusional variant participated in an 8-week, placebo-controlled, double-blind, parallel-group study of pimozide augmentation of fluoxetine.

RESULTS

Pimozide was not more effective than placebo: two (18.2%) of 11 subjects responded to pimozide and three (17.6%) of 17 subjects responded to placebo. There was no significant effect of baseline delusionality on endpoint severity of body dysmorphic disorder. Delusionality did not decrease significantly more with pimozide than placebo.

CONCLUSIONS

Pimozide augmentation of fluoxetine treatment for body dysmorphic disorder was not more effective than placebo, even in more delusional patients. Further studies of augmentation for SRIs are needed.

Treatment with medications affecting dopaminergic and serotonergic mechanisms: effects on fluency and anxiety in persons who stutter

Medications with dopamine antagonist properties, such as haloperidol, and those with serotonin reuptake inhibitor properties, such as clomipramine, have been shown to improve fluency. To examine the degree to which each of these two pharmacological mechanisms might independently affect fluency, a selective serotonin reuptake inhibitor, paroxetine, and a selective dopamine (D-2) antagonist, pimozide, were evaluated. Both types of medications also affect mood and anxiety, factors that could influence fluency levels. Therefore, we also evaluated the medications' effects on generalized and speech-related anxiety and the relationships between changes in anxiety and changes in fluency in 11 subjects with a history of developmental stuttering. The randomized, double blind, placebo-controlled crossover study that was designed had to be terminated prior to completion due to severe side effects following withdrawal from paroxetine. Even with a reduced sample size (n=6), significant improvement in percent fluent speaking time (p=0.02) was found using a telephone task between baseline and pimozide (n=6), with average duration of dysfluencies significantly shorter (p=0.04) but no significant difference in the estimated number of dysfluencies per minute. This significant improvement was associated with non-significant increases in generalized anxiety, but non-significant decreases in speech-related anxiety. No significant differences were found in fluency between baseline and paroxetine (n=5). These preliminary results suggest that fluency improvement is more likely to be mediated by dopaminergic rather than serotonergic mechanisms. Due to its side effects, however, pimozide may be considered a risk for treatment of stuttering.

EDUCATIONAL OBJECTIVES

As a result of reading this paper the reader will describe and explain: (1) how medications may affect fluency and the rationale for selecting medications for treatment trials; (2) the interrelationship between fluency and anxiety; and (3) factors important in developing clinical trials using medications.

Effects of medications on regulation of body temperature of patients with Tourette syndrome

Tourette syndrome is defined and characterized mainly by the presence of motor and phonic tics. Frequently, other medical, psychologic, and psychiatric symptoms coincide with Tourette syndrome. Despite extensive efforts extended over many years of research, the etiology leading to Tourette syndrome remains obscure. A number of hypotheses have been offered in the past to resolve the pathophysiology of Tourette syndrome. Based on the existence of an abnormal body temperature profile in patients with Tourette syndrome, an idiopathic hypothalamic disorder has been proposed to be involved in this ailment. When monitoring the effects of medications employed in the consensus for Tourette syndrome treatments, it became evident that medications ameliorate neurologic tics and rectify the patient's periodic hypothermal body temperature. Correlating the neurologic status to hypothalamic dysregulation, the data presented in this study strengthen the hypothesis of an idiopathic hypothalamic disorder underlying the Tourette syndrome cascade.

Tic reduction with risperidone versus pimozide in a randomized, double-blind, crossover trial

OBJECTIVE

To compare the tic suppression, electrocardiogram (ECG) changes, weight gain, and side effect profiles of pimozide versus risperidone in children and adolescents with tic disorders.

METHOD

This was a randomized, double-blind, crossover (evaluable patient analysis) study. Nineteen children aged 7 to 17 years with Tourette's or chronic motor tic disorder were randomized to 4 weeks of treatment with pimozide or risperidone, followed by the alternate treatment after a 2-week placebo washout. The primary efficacy outcome measure was change in tic severity assessed by the Yale Global Tic Severity Scale (YGTSS). ECG results, weight gain, and side effects were also compared.

RESULTS

Compared to pimozide treatment, risperidone treatment was associated with significantly lower tic severity scores (YGTSS: baseline 43.3 +/- 17.5, pimozide 34.2 +/- 14.2, risperidone 25.2 +/- 13.6; p =.05). Weight gain during the 4-week treatment periods was greater for risperidone (mean 1.9 kg) than pimozide (1.0 kg). No patient suffered a serious adverse event, but 6 of 19 subjects failed to complete the protocol. Neither medication was associated with ECG changes.

CONCLUSIONS

In this study, risperidone appeared superior to pimozide for tic suppression but was associated with greater weight gain.

Delusional parasitosis: case series of 8 patients and review of the literature

INTRODUCTION

Delusional parasitosis (DP) is a condition in which a person has the unshakeable and mistaken belief of being infested with parasites.

PATIENTS AND METHODS

All patients with DP seen by the Division of Dermatology, Department of Medicine, National University Hospital were reviewed. The case histories of 8 Chinese patients are discussed.

RESULTS

The patients with DP were predominantly women above 50 years of age, with medical co-morbidities and presented with a variety of symptoms and signs. The patients were prescribed various antipsychotics including the atypical antipsychotics. Response was variable, and the patients often defaulted follow-up. An approach to the management of DP is proposed together with a review of the literature.

Pimozide in dermatologic practice: a comprehensive review

Pimozide is an antipsychotic drug of the diphenylbutylpiperidine class. In the US, it is FDA-approved only as a backup treatment for Gilles de la Tourette syndrome, although it has been used in other countries for many years as a treatment for schizophrenia. In the past 20 years, pimozide has been found to be especially efficacious in the treatment of monosymptomatic hypochondriacal psychoses and is used by psychiatrists and dermatologists for this off-label purpose. In particular, pimozide is considered the treatment of choice for delusions of parasitosis. In addition, pimozide has been found to be efficacious in the treatment of body dysmorphic disorder, metastatic melanoma, trichotillomania, and trigeminal and postherpetic neuralgia. This review aims to familiarize physicians, especially dermatologists, on the uses of pimozide in dermatologic practice. A review of the literature was performed and the relevant information synthesized to give a complete overview of the drug and its therapeutic uses in dermatology.

Pimozide: use in dermatology

Pimozide is widely used in psychiatry for chronic psychoses, schizophrenia, the syndrome of Gilles de la Tourette and to a certain extent, also in dermatology. The only dermatological indication is for delusions of parasitosis. Though there is a good rationale for using pimozide in this disease, the majority of the studies on pimozide in dermatology are uncontrolled trials and case reports.

[A child with peculiar movements: Sydenham chorea]

An 11-year-old girl with Sydenham chorea presented with a rapid onset of serious restlessness of mainly the right side of the body. Additional laboratory investigations revealed no abnormalities, yet this is not unusual for such cases. Valproic acid and pimozide were then successively prescribed because of the chorea. For secondary prevention she received long-term oral penicillin. Sydenham chorea is a manifestation of rheumatic fever and occurs after a throat infection by group A streptococci. The disease is characteristic and consists of a combination of choreic movements, hypotonia and emotional lability. The clinical course is diverse. Improvement usually occurs over a period of several months, although a significant proportion of patients exhibit little recovery.

P300 changes in major depressive disorders with and without psychotic features

BACKGROUND

Although there are many P300 studies in depressive patients, only a few studies have focused on the effects of psychotic features in depression and of response to antidepressant treatment on P300. This study was designed to investigate possible differences in the P300 component of event-related potentials in depressed patients with and without psychotic features and if any, to see whether these changes altered with treatment of depression.

METHODS

Thirty-six patients with major depressive disorder diagnosed according to DSM-IV, and 20 healthy control subjects were involved in the study. Sixteen of the patients had psychotic features. Auditory P300 was recorded before treatment and after remission.

RESULTS

Pretreatment P300 latencies were significantly prolonged both in patients with and without psychotic features compared to controls. Pretreatment P300 amplitudes were significantly decreased only in the patients with psychotic features. After treatment of depression, delayed P300 latencies in both patient groups and decreased P300 amplitude in the patient group with psychotic features were normalized.

LIMITATIONS

The medication status of the patient was heterogeneous.

CONCLUSION

Since the impairment seems to be improved by drug treatment, prolonged P300 latency might be a state marker for a major depressive episode, and decreased P300 amplitude which is correlated with paranoid ideation might be more associated with psychotic subtype.