Dyskinesia due to mexiletine overdose: a rare presentation

BACKGROUND

Mexiletine, a class IB antiarrhythmic, is a structural analog of lidocaine. Our knowledge of mexiletine overdose is based on lidocaine overdose reports. Only a few cases of mexiletine overdose have been reported, including fatal overdoses. Mexiletine toxicity primarily affects the central nervous, cardiovascular, and gastrointestinal systems.

CASE

A 16-year-old female was brought to our hospital by ambulance after taking an unknown dose of mexiletine in a suicide attempt. Ventricular fibrillation developed while in the ambulance; cardiopulmonary resuscitation was started and spontaneous circulation returned within 1 min. The patient had been taking oral mexiletine for 1 month to treat primary erythromelalgia. Her vital signs were normal, but she was unconscious. Following gastric lavage she was transferred to the pediatric intensive care unit. Midazolam and levetiracetam were required due to uncontrolled seizures. During the first hour of hospitalization, severe dyskinesia characterized by abnormal involuntary large hyperkinetic movements in all 4 extremities was observed and successfully treated with 2 doses of intravenous biperiden. The patient was discharged on day 6 of hospitalization.

CONCLUSIONS

Mexiletine overdose can be life-threatening. In addition to rapid and effective resuscitation, rapid identification and management of cardiovascular and central nervous system manifestations are key to preventing morbidity and mortality. The presented case had severe dyskinesia that was successfully treated with repeated doses of biperiden. Biperiden did not cause arrhythmia. Based on the presented case, we think biperiden should be considered for the treatment of movement disorders in cases of mexiletine overdose.

Childhood dystonic reactions in the middle Black Sea region

Acute dystonic reactions are a worrying reason for presentation to the pediatric emergency department and the pediatric neurology clinic in childhood. It must be diagnosed and treated quickly. The aim of this study was to examine the clinical presentations, etiological factors, and prognosis of patients presenting to our regional tertiary pediatric neurology clinic with a diagnosis of acute dystonic reactions in children.Nine pediatric patients who were treated for acute dystonic reactions between May, 2018 and May, 2020 and had adequate follow-up were included in the study. Medical record data were reviewed age, gender, etiology, features of family, treatment, and results.Three of the patients were female and 6 were male. Their average age was 11 years (4-17). All patients were evaluated as a drug-induced acute dystonic reaction. Of the 9 patients, 5 were due to metoclopramide, 3 were due to risperidone, and 1 was due to aripiprazole. It was learned that a similar situation against other drugs developed in the family history of 3 patients. As a treatment, all of them were intramuscularly applied biperiden suitable for their weight and 30 minutes dramatic improvement was observed. Additional dose had to be administered in only 1 case. All cases were discharged for 24 hours. No problem was observed in their follow-up.Drug-induced acute dystonic reaction can be diagnosed and has a clinical picture that completely resolves when effective treatment is applied. However, it should not be forgotten that it can reach life-threatening dimensions clinically.

[The use of biperiden (akineton) in patients with ephedrone encephalopathy]

An open comparative cross-over trial of the selective central M1 cholinoreceptors blocker - biperiden (akineton) was carried out in 35 patients with efedron encephalopathy (EEP) with mean illness duration 6,9 years. Patients received biperiden in individually adjusted dose, maximally up to 10 mg daily. Seventeen patients initially were treated with trihexyphenidyl in dosage 10 mg daily with switching to biperiden after 3 months. The total duration of treatment was 6 months. There was a significant decrease on the Fahn-Marsden scale and a clinical EEP scale, along with the moderate improvement quality of life assessed with the EQ-5D and the increase of the Barthel index. The decrease on the Fahn-Marsden scale by more than 30% was found in 40% patients treated with biperiden during 6 months and in 29% patients treated with trihexyphenidyl. Among patients switched to biperiden, 36% preferred to continue with the drug and only 12% preferred trihexyphenidyl.

The use and potential abuse of anticholinergic antiparkinson drugs in Norway: a pharmacoepidemiological study

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Anticholinergic antiparkinson drugs are used to ameliorate extrapyramidal symptoms caused by either Parkinson's disease or antipsychotic drugs, but their use in the treatment of Parkinson's disease is assumed to be in decline. Patients with psychotic conditions have a high prevalence of abuse of drugs, including anticholinergic antiparkinson drugs.

WHAT THIS STUDY ADDS

Anticholinergic antiparkinson drugs in Norway were primarily prescribed to patients using antipsychotic medication. The risk of abuse of this group of drugs was small, even among patients who probably abused other drugs.

AIMS

The use of anticholinergic antiparkinson drugs is assumed to have shifted from the therapy of Parkinson's disease to the amelioration of extrapyramidal adverse effects induced by antipsychotic drugs. There is a considerable body of data suggesting that anticholinergic antiparkinson drugs have a potential for abuse. The aim was to investigate the use and potential abuse of this class of drugs in Norway.

METHODS

Data were drawn from the Norwegian Prescription Database on sales to a total of 73 964 patients in 2004 of biperiden and orphenadrine, and use in patients with Parkinson's disease or in patients who were also prescribed antipsychotic agents. Possible abuse of these drugs was assessed by the level of use, skewedness of use, indications of drug-seeking behaviour and concomitant use of benzodiazepine tranquillizers, a group of prescription drugs with a recognized potential for abuse.

RESULTS

Anticholinergic antiparkinson drugs were prescribed to 4.5% of all outpatients who used antipsychotic drugs. This outnumbered sales to patients with Parkinson's disease by >20 to 1. We found indications of abuse of benzodiazepine tranquillizers among patients using antipsychotics, but there were no clear indications of abuse of anticholinergics, even among patients who were strongly suspected of abuse of benzodiazepines.

CONCLUSIONS

Anticholinergic antiparkinson drugs were used primarily by patients with psychotic illnesses. These patients have a very high prevalence of legal and illegal drug abuse, but the risk of abuse of anticholinergic antiparkinson drugs seemed small.

The effectiveness of intramuscular biperiden in acute akathisia: a double-blind, randomized, placebo-controlled study

Neuroleptic-induced acute akathisia (NIA) is a distressing condition and an important clinical problem because it is associated with treatment noncompliance and suicidal or impulsive behavior. Anticholinergics are among the treatment options; however, a review of the literature fails to identify a double-blind, randomized, placebo-controlled study of these medications in NIA. In a randomized, double-blind, placebo-controlled design, we studied the effectiveness of intramuscular biperiden (n = 15) or isotonic saline (n = 15) in the treatment of NIA diagnosed with the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria. Injections were repeated up to 3 times unless akathisia was completely treated (scored 0 for global akathisia with the Barnes Akathisia Rating Scale). Patients were assessed for akathisia, other movement disorders, and psychiatric symptoms at baseline and 3 times after the first injection at 2-hour intervals. Response was defined as at least a 2-point decline in the global akathisia score. The numbers of responders in the 2 groups were not significantly different (7 and 5 in the biperiden and placebo groups, respectively). The courses of individual items on the Barnes Akathisia Rating Scale were also similar. Our results suggest that intramuscular biperiden should not be considered as a first-line treatment of NIA.

Neuroleptic malignant syndrome induced by ziprasidone on the second day of treatment

Neuroleptic malignant syndrome (NMS) is the rarest and most serious of the neuroleptic-induced movement disorders. We describe a case of neuroleptic malignant syndrome (NMS) associated with the use of ziprasidone. Although conventional neuroleptics are more frequently associated with NMS, atypical antipsychotic drugs like ziprasidone may also be a cause. The patient is a 24-year-old male with a history of schizophrenia who developed signs and symptoms of NMS after 2 days of treatment with an 80-mg/day dose of orally administrated ziprasidone. This case is the earliest (second day of treatment) NMS due to ziprasidone reported in the literature.

Administration of haloperidol with biperiden reduces mRNAs related to the ubiquitin-proteasome system in mice

In order to find molecules affected by administration of an antipsychotic drug with an antimuscarinic drug, which is a common prescription used to prevent extrapyramidal adverse effects caused by the antipsychotic drugs, gene expression profiling in the frontal cortex was studied in mice. After 14 days of administration with 2 mg/kg haloperidol, a typical antipsychotic drug, and 2 mg/kg biperiden, a high-affinity antagonist for muscarinic receptors in the brain, approximately 500 mRNAs related to synaptic function were investigated. The levels of the mRNAs related to the ubiquitin-related systems were significantly reduced after the combined administration. However, the separate administration of either haloperidol or biperiden had little effect on the levels of the mRNAs. This result suggests that coadministration of haloperidol and biperiden specifically affects the ubiquitin-related system.

Effects of discontinuation of long-term anticholinergic treatment in elderly schizophrenia patients

Anticholinergic medication (ACM) is frequently used in psychiatry to treat the side-effects of D2 blocking agents. However, ACM is not without adverse effects and, in the elderly, cognitive and memory impairments have been emphasized. The aim of this study was to evaluate the effects of discontinuation of ACM on cognitive functions in a group of elderly chronic schizophrenia patients. Twenty-seven elderly patients (age 60 years or older), who were diagnosed as suffering from schizophrenia (DSM-IV) and receiving ACM in addition to antipsychotic treatment, were enrolled. Before and after ACM was discontinued, the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) subscale was administered. Twenty-one patients completed the study. All were receiving Akineton (biperiden), 2-6 mg daily before the study. Significant improvement in the ADAS-Cog total score was demonstrated (P < 0.03), as well as in the ideational praxia and orientation subscales. Improvement was correlated with the previous dose of biperidin. No adverse events or emergent extrapyramidal symptoms were noted. Discontinuation of ACM may be warranted in chronic schizophrenia patients since it may improve cognitive functioning with no adverse effects.

The determination of biperiden in plasma using gas chromatography mass spectrometry: pharmacokinetics after intramuscular administration to guinea pigs

A gas chromatographic-mass spectrometric (GC-MS) method has been developed for the analysis of the biperiden from plasma. The method utilizes 290 microl of plasma and a simple hexane extraction/clean-up procedure. Standard curves were linear over the range of 1.9-250 ng/mL. The range of correlation coefficients for the individual standard curves was 0.9984-0.9999; the largest coefficient of variation expressed as a percentage (% CV) was 11.5%. Precision and accuracy were examined by assessing between-day and within-day variability. For between-day precision, the % CVs ranged from 2.86 to 5.17%. Accuracy as expressed by percentage error ranging from -2.16 to 5.83%. The study for within-day precision demonstrated % CVs from 0.95 to 5.55% with accuracy from -3.37 to 2.45%. Applicability of the method was demonstrated by examining the pharmacokinetics of intramuscular (i.m.) biperiden as an anticonvulsant treatment in a guinea pig model for organophosphate (OP)-induced seizure activity. Mean pharmacokinetic parameter estimates were similar to literature values; selected mean pharmacokinetic parameter estimates were: apparent volume of distribution, 13.9 L/kg; half-life of elimination, 93 min; time to maximal plasma concentration, 27.4 min; and maximal plasma concentration, 32.22 eta g/mL. The time to maximal plasma concentration was found to be similar to the onset time for terminating OP-induced seizure activity in guinea pigs receiving biperiden as an anticonvulsant treatment. The studies indicate that the method affords the required precision, accuracy and sensitivity to assay biperiden at the doses utilized for these pharmacokinetic studies after i.m. administration to guinea pigs.

The influence of pilocarpine and biperiden on pH value and calcium, phosphate, and bicarbonate concentrations in saliva during and after radiotherapy for head and neck cancer

OBJECTIVE

The purpose of the present study was to investigate the influence of parasympathomimetic pilocarpine and anticholinergic biperiden on salivation, pH value, and calcium, phosphate, and bicarbonate concentrations in saliva in patients irradiated for malignant tumors of the head and neck region.

STUDY DESIGN

Sixty-nine patients were randomly assigned into 3 groups. Group A consisted of patients receiving pilocarpine, group B of those who were receiving biperiden during radiotherapy and pilocarpine for 6 weeks after its completion, and group C comprised patients receiving neither of the mentioned drugs. The quantity of secreted unstimulated saliva, its pH value, as well as calcium, phosphate, and bicarbonate concentrations in saliva were measured before the beginning of radiotherapy, after 30 Gy of irradiation, at completed irradiation, and 3, 6, and 12 months after completion of radiotherapy.

RESULTS

Saliva secretion was found to be the least affected in the group of patients receiving biperiden throughout the course of radiotherapy. One year after completion of therapy, the quantity of secreted saliva could only be measured in the patients receiving biperiden during radiotherapy; it amounted to 16% of the average initial quantity of saliva secreted before the beginning of irradiation. In all 3 groups of patients, mean pH value decreased during radiotherapy and started to increase again after completion of irradiation. In group B the decrease in pH value after radiotherapy was statistically significantly smaller than that in group C (P =.01). During and after irradiation, calcium concentration was increased in all 3 groups of patients. Phosphate concentration decreased during radiotherapy in all 3 groups. In group B it started to increase again 3 months after completion of radiotherapy. Bicarbonate concentration showed a slight increase during radiotherapy and started to decrease again after completion of irradiation.

CONCLUSION

The results of our study indicate that the inhibition of saliva secretion during radiotherapy and its stimulation after completion of treatment can contribute not only to some preservation of the quantity of saliva but also to at least partial preservation of its quality in terms of pH value and calcium, phosphate, and bicarbonate concentrations.

Intravenous biperiden in akathisia: an open pilot study

OBJECTIVE

Antipsychotic-induced akathisia can be distressing and unendurable for prolonged periods. It has been shown that intramuscular biperiden is a relatively rapid and effective treatment for akathisia. However, the intravenous administration of biperiden may provide a more rapid effect, although this remains to be definitively proven.

METHOD

The subjects obtained for this study met the diagnostic criteria for schizophrenia as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). The therapeutic effect of i.v. and i.m. biperiden was studied in an open clinical trial in twenty-three (12 male and 11 female) patients who developed antipsychotic-induced acute akathisia as defined by the research criteria of the DSM-IV. Following the development of akathisia, 5 mg of biperiden was intravenously injected in seventeen patients and intramuscularly in six patients. The therapeutic effect of biperiden on akathisia was clinically assessed by using the rating scale of Barnes.

RESULTS

Following i.v. administration on biperiden, the mean time to onset and maximum effect occurred 1.6 (SD = 1.9) and 9.2 minutes (SD = 6.0), respectively. Furthermore, at the time of maximal effect, akathisia was completely ameliorated in all patients. The side effects reported were mild and transient. Following i.m. administration, the mean time to onset and maximum effect were 30.5 (SD = 5.9) and 50 minutes (SD = 7.4), respectively. Thus, the time to maximal effect was significantly less (40 minutes) after i.v. compared to i.m. administration.

CONCLUSION

These results suggest that i.v. administration of 5 mg of biperiden could be used to provide a rapid and effective treatment for patients with severe akathisia.

Muscarinic receptor occupancy by biperiden in living human brain

Anticholinergic drug is often used to treat extrapyramidal symptoms. We measured muscarinic cholinergic receptor (mAchR) occupancy by the oral administration of biperiden in eight healthy subjects using positron emission tomography (PET) and [11C]N-methyl-4-piperidylbenzilate (NMPB). After the baseline scan each subject underwent one or two post-dose PET scans. mAchR occupancy was 10-45% in the frontal cortex three hours after the oral administration of 4 mg of biperiden. The occupancy correlated with the plasma concentration of biperiden in a curvilinear manner.

Panic attacks in patients with chronic schizophrenia: a complication of long-term neuroleptic treatment

Panic attacks meeting the diagnostic criteria for panic disorder (DSM-III-R) were found in nine (20%) of 45 patients suffering chronic schizophrenia for more than 5 years. The scores of the Hamilton Depression Rating Scale and the Simpson Angus Scale were significantly higher in the group of patients with panic attacks. They also tended to be taking neuroleptics in larger doses than in the other group. The present report suggests that long-term treatment with neuroleptics is closely related to the manifestation of panic attacks in chronic schizophrenia. It also suggests that when panic attacks are seen frequently in patients taking high doses of neuroleptics, dose reduction of neuroleptics should be considered.

Influence of ammonium chloride on the tissue distribution of anticholinergic drugs in rats

Ammonium chloride (NH4Cl) increases lysosomal pH and thereby abolishes intralysosomal accumulation of drugs. Its effect on the tissue distribution of biperiden and trihexyphenidyl in rats has been investigated. The tissue-plasma concentration ratios (Kp) of these drugs in various tissues were determined by infusion studies at steady-state in the presence or absence of NH4Cl. Treatment with NH4Cl reduced the Kp values for both drugs, causing the largest reduction in Kp in the lung (52.1 to 11.8 for biperiden and 59.5 to 18.9 for trihexyphenidyl; ratios of decrease 0.77 and 0.68, respectively), followed by the heart and kidneys, with relatively small reductions in the brain, gut, muscle and fat. Subcellular fractionation studies in the lung indicated that the subcellular fraction-plasma concentration ratio of each drug at the steady state (K(p,sf)) was reduced by treatment with NH4Cl, with the largest decrease in the post-nuclear fraction (ratio of decrease 0.82 for biperiden and 0.74 for trihexyphenidyl), followed by the nucleus, microsomes and supernatant, in that order. A strong correlation was found between the ratio of decrease in K(p,sf) after NH4Cl treatment and the specific activity of acid phosphatases, a marker of lysosomes, in each fraction (biperiden, r = 0.948; trihexyphenidyl, r = 0.945). These results suggest that acidic organelles contribute significantly to the distribution kinetics of anticholinergic drugs.

[Schizophrenia-like symptoms in the Westphal-Strümpell variation of Wilson disease]

Wilson's disease is a rare, autosomal recessive disorder of copper metabolism due to low serum ceruloplasm, resulting in increased copper deposition, especially in the liver and basal ganglia in the brain. The pseudosclerotic type of Wilson's disease, also known as the Westphal-Strümpell form, is distinguished by positional tremor, ataxia and dysarthria as the main symptoms. We use the example of a 23-year-old patient whose neurological symptoms were preceded by a long history of a schizophrenic-like disorder. Clinical symptoms are presented. MRI, SPECT and PET images are illustrated. Therapy and outcome are discussed.

Effect of sequence of administration on the pharmacokinetic interaction between the anticholinergic drug biperiden and [3H]quinuclidinyl benzylate or [3H]N-methylscopolamine in rats

In rats the pharmacokinetic interactions between the anticholinergic drug biperiden and [3H]quinuclidinyl benzylate ([3H]QNB) or [3H]N-methylscopolamine ([3H]NMS) is affected by the sequence in which the drugs are administered. Drug concentrations in various tissues were determined after intravenous administration of [3H]QNB or [3H]NMS (325 ng kg(-1)). Biperiden (6.4 mg kg(-1)) was administered either 5 min before, concomitantly with or 20 min after injection of [3H]QNB or [3H]NMS. When biperiden was administered concomitantly with or before [3H]QNB, distribution of [3H]QNB among the regions of the brain and other tissues was reduced; at 4 h the ratio of the distribution of [3H]QNB for experimental animals to that for control animals ranged from 0.15 to 0.9. When biperiden was administered after [3H]QNB, the distribution of [3H]QNB in the brain and other tissues was significantly higher than for the other two treatments (P < 0.01). However, for [3H]NMS the sequence of administration had no effect on the distribution of the drug in the brain and other tissues except for the kidney. In-vitro, in crude synaptosomal membranes, the amount of [3H]QNB at 2 h relative to the control concentration at equilibrium was 87% when biperiden was added before [3H]QNB and 56% when biperiden was added after [3H]QNB. In both instances the concentration of [3H]NMS reached equilibrium within 30 min. These findings suggest that the difference between the rate constant of association and dissociation at the possible site of action gives rise to the effect of the sequence of administration on the pharmacokinetic interaction.

[Acute life threatening catatonia--clinical significance and therapeutic possibilities]

Malignant catatonia, associated with different somatic and psychiatric disorders, is a rare, life-threatening syndrome. Immediate recognition and adequate treatment are essential and may be life-saving. We describe a case of malignant catatonia and discuss the clinical implications. Additionally, we review the recent literature regarding epidemiology, nosology, current pathophysiological concepts, differential diagnosis, and treatment recommendations.

Recurrent paroxysmal episodes characterized by perceptual alteration in three schizophrenic patients on neuroleptic medication

A suddenly occurring episode characterized by perceptual alteration (SEPA), mainly of visual and/or auditory modalities, which repeatedly occurred in three schizophrenic patients on long-term neuroleptic medication, is described. Perceptual alteration showed some distinct features that were different from acute symptoms of schizophrenia, and was accompanied by mood changes such as severe anxiety and agitation and, in one of the patients, also by extrapyramidal symptoms. Perceptual alteration, as well as mood changes and extrapyramidal symptoms, responded well to an anticholinergic drug, biperiden. Recent studies have shown that SEPA occurred not only in schizophrenic patients but also in patients on long-term neuroleptic medication for treating other mental disorders. These findings suggest that SEPA is associated with dopaminergic hypoactivity in the brain, which is induced by long-term neuroleptic medication.

Biperiden and haloperidol plasma levels and extrapyramidal side effects in schizophrenic patients

Anticholinergic drugs such as biperiden are used for the treatment of extrapyramidal side effects (EPS) induced by neuroleptics such as haloperidol. The effects of biperiden and haloperidol plasma levels on EPS were studied in 29 chronically ill schizophrenics. The results show relationships between biperiden dose and biperiden plasma levels (BPL), and between BPL and haloperidol plasma levels (HPL). Neither BPL nor HPL seem to influence EPS.

Contrasts in neuropsychological test profile between patients with first-episode schizophrenia and first-episode affective disorders

Patients with first-episode (FE) schizophrenia (n = 27), unipolar depression (n = 10) and bipolar disorder (n = 17) and age- and gender-matched healthy control subjects (n = 27) were administered a battery of neuropsychological (NP) tests. FE schizophrenics performed significantly less well than patients with affective disorders in the area of visual motor processing and attention. Affective disorder patients without psychotic features did not perform significantly differently to controls. However, affective disorder patients with psychotic features performed as poorly as schizophrenics, with the most pronounced impairment in the area of visual motor processing and attention. Our data tentatively suggest the existence of a dichotomy in neuropsychological impairment, with psychotic patients showing similar neuropsychological deficits, while non-psychotic affective patients perform comparably to controls.

Stuttering may be a type of action dystonia

We observed abnormal involuntary movements, involving principally the facial and neck muscles, in 23 patients with stuttering. These movements were similar to involuntary movements seen in distinct dystonic syndromes. There was a history of stuttering in the first degree relatives of six patients. The association of stuttering with degenerative neurologic disorders and focal brain lesions, cerebral blood flow changes in patients with developmental stuttering, its occurrence as a side effect of centrally acting drugs, induction and alleviation of stuttering by mechanical perturbation, or by electrical stimulation of the thalamus, a strong genetic predisposition with male preponderance, and the statistically significant occurrence of stuttering in the family history of patients with idiopathic torsion dystonia suggest an organic basis for developmental stuttering. These findings and the reported similarities between the involuntary movements associated with stuttering and dystonic involuntary movements support the hypothesis that stuttering is a form of segmental or focal action dystonia.

[Torticollis spasmodicus as a manifestation of tardive dystonia]

Tardive dystonia is a subtype of tardive dyskinesia which is rarely recognised and diagnosed. Tardive dystonia occurs clearly less frequently than oro-bucco-lingual dyskinesia (approx. 1 vs. 20%). We present a case report and give a survey on the characteristics of tardive dystonia, its differential diagnosis and treatment as described in literature.

Effects of biperiden and amantadine on memory in medicated chronic schizophrenic patients. A Double-blind cross-over study

BACKGROUND

The effects on memory of an anticholinergic (biperiden) and a dopaminergic (amantadine) anti-Parkinsonian agent were compared.

METHOD

Twenty-six chronically medicated schizophrenic (DSM-III-R) in-patients received amantadine (200 mg/day) or biperiden (4 mg/day) for two weeks in a double-blind cross-over design.

RESULTS

Biperiden treatment was associated with significantly lower scores on Benton Visual Retention Test (P < 0.003) and the visual subscale of Wechsler Memory Scale (WMS) (P < or = 0.02), with a trend to poorer scores on WMS total (P = 0.086) and the digit span (P = 0.07) and logical memory (P = 0.06) subscales.

CONCLUSIONS

In usual clinical doses, biperiden interferes with memory, particularly visual, more than amantadine.

Cholinergic neurotransmission seems not to be involved in depression but possibly in personality

Concordant with the adrenergic-cholinergic imbalance hypothesis of affective psychosis, there is a cholinergic supersensitivity in depression. Thus, the anticholinergic properties of some antidepressants might contribute to their efficacy. However, in the present double-blind studies (n = 20) with mianserin and viloxazine, respectively, which lack anticholinergic properties, adjunctive treatment with the anticholinergic biperiden versus placebo did not enhance the antidepressive efficacy. Therefore, we hypothesized that cholinergic supersensitivity might be linked to some possibly predisposing dimension of personality. Indeed, in healthy male volunteers (n = 11) the behavioral and cardiovascular sensitivity to physostigmine correlated significantly with "irritability" and "emotional lability" as well as with habitually passive strategies in stress coping. The rise in plasma cortisol and norepinephrine correlated with "retardation"; that of epinephrine with active coping. Thus, the cholinergic supersensitivity in affective psychoses might be linked to a personality dimension like stress sensitivity rather than to the diagnostic category itself.

[Early dyskinesia with administration of clozapine (Leponex)]

A 51-year old, female patient suffering from schizophrenic disorder was treated with clozapine (Leponex). Four hours after the first parenteral, drug administration, she developed an acute dyskinesia.

Extrapyramidal syndrome responsive to dopaminergic treatment following recovery from central pontine myelinolysis

A 52-year-old woman developed severe hyponatremia following treatment for hypertension with chlorthalidone. Rapid correction of hyponatremia resulted in coma, quadriplegia and hypopnea compatible with central pontine myelinolysis. She recovered with residual facial hypomimia, bradykinesia, cogwheel rigidity and coarse resting tremor, responding to dopaminergic treatment. Her symptoms and signs, which are quite similar to idiopathic Parkinson's disease, are still responsive to treatment 7 years after onset.

[Extrapyramidal movement disorders after "Isostar Cocktail"]

Two children developed extrapyramidal symptoms after taking an electrolyte drink. There was a good response to Biperidon (Akineton). Only exact investigations showed that both children had accidentally been poisoned by a neuroleptic drug which was added to the electrolyte mixture.

Distinguishing acute and tardive akathisia by monitoring microvibration: a pilot study

One acute and one tardive akathisia patients, respectively, and 10 neuroleptic-treated schizophrenic patients were injected with biperiden 5 mg or saline and the response to anticholinergics was monitored by microvibration (MV) as an indicator of muscle tonus. These data were subjected to the Fast Fourier Transform and an averaged power spectrum was computed. The biperiden injection markedly reduced the power spectral values of MV in acute akathisia. In contrast with acute akathisia, the biperiden injection significantly increased the power spectral values of MV in tardive akathisia. The subjective feelings of akathisia patients were parallel to the power spectral values of MV. Control patients were not affected by such treatment. The present findings show that the subjective symptoms of akathisia can be well defined by the objective, differential response to anticholinergics in a manner similar to the visible extrapyramidal symptoms (dystonia, dyskinesia) induced by neuroleptics.

[Neuroleptic malignant syndrome--a case report on diagnosis, differential diagnosis and therapy of a life threatening complication of treatment with neuroleptics]

The neuroleptic malignant syndrome is a potentially lethal consequence of treatment with neuroleptics. It is possible that a patient, suffering from neuroleptic malignant syndrome now, had no such illness in the past, while being treated with neuroleptics; furthermore he may respond well to rechallenge with the original agent in the future. The malignant neuroleptic syndrome of a 29 year old man, whom we treated with benperidole, is described. The course of the disease and the differential-diagnosis is stated. The ways of treatment with bromocriptine, dantrolene sodium and amantadine, as described in the literature, are presented. As the neuroleptic malignant syndrome ist rare many cases should be collected in order to enhance the knowledge of the etiology and the pathogenesis of that life--threatening complication of treatment with neuroleptic drugs.

Zuclopenthixol and haloperidol in patients with acute psychotic states. A double-blind, multi-centre study

A double-blind, multi-centre study was carried out in 49 hospitalized patients with an acute psychosis or an exacerbation of a chronic psychosis to compare the wanted and unwanted effects of the neuroleptics, zuclopenthixol and haloperidol. Patients were allocated at random to receive treatment with one or other of the trial drugs for 8 weeks or until discharge. Five patients on zuclopenthixol and 6 on haloperidol were excluded from the efficacy analyses because they did not complete a minimum of 4-weeks' treatment. Dosage was chosen and adjusted to the individual patient's condition and response. The average daily doses in Week 4 were 33.5 mg and 10.3 mg, respectively. Clinical assessments, including CGI, BPRS and the UKU side-effect scale, were done at baseline, and after 1, 2, 4, 6 and 8 weeks of treatment or at discharge if the patient was discharged earlier than Week 8. Both treatments caused a significant reduction in scores with no between-group differences. More patients in the zuclopenthixol group were discharged early indicating slightly more rapid onset of action. Zuclopenthixol caused a significantly greater improvement in 'anxious-depression' factor score than haloperidol. The most frequent unwanted effects were extrapyramidal symptoms and there were no significant differences between the groups. The extrapyramidal symptoms tended to be transient in the zuclopenthixol group, but not in the haloperidol group. The study confirmed that both zuclopenthixol and haloperidol were effective drugs in the treatment of acute, psychotic patients. There was a trend towards a slightly more rapid onset of effect and a somewhat stronger anxiolytic-antidepressant effect by zuclopenthixol compared to haloperidol.

Effects of biperiden on sleep at baseline and after 72 h of REM sleep deprivation in the cat

We examined the effects of the muscarinic M1 antagonist biperiden in cats. In the first experiment a dose-response analysis was performed with intraventricular injection (IV ventricle) of biperiden. In the second experiment after REM sleep deprivation cats were injected with either biperiden (0.1 mg/kg) or saline. Biperiden produced a reduction in REM sleep percentage and an increase in REM sleep latency with these high doses. The 0.1 mg/kg biperiden dose, which did not suppress REM sleep at baseline, did reduce the REM sleep rebound. The present study suggests a modulatory role of biperiden on REM sleep regulatory processes. The fact that an effect of biperiden is noted only at the high doses suggests that at these doses the drug is influencing non-M1 receptors. Changes in the sensitivity of these receptors as a result of REM sleep deprivation might explain why a dose of biperiden will reduce REM sleep rebound, while being ineffective in suppressing REM sleep at baseline.

The effects of baclofen and cholinergic drugs on upbeat and downbeat nystagmus

The GABAergic drug baclofen and the cholinergic drug physostigmine were administered to patients with upbeat and downbeat nystagmus. Baclofen (orally, 5 mg three times daily) reduced nystagmus slow phase velocity and distressing oscillopsia by 25-75% in four out of five patients (two upbeat nystagmus; two downbeat nystagmus). Physostigmine (1 mg single intravenous injection) increased nystagmus in five additional patients with downbeat (1) or positional downbeat nystagmus (4) for a duration of 15-20 minutes. The different interactions of baclofen and physostigmine on neurotransmission subserving vertical vestibulo-ocular reflex could account for these effects. The response to baclofen appears to be a GABA-B-ergic effect with augmentation of the physiological inhibitory influence of the vestibulo-cerebellum on the vestibular nuclei. Similarly baclofen has an inhibitory effect on the velocity storage mechanism. Cholinergic action may cause the increment of nystagmus by physostigmine.

Synergistic interactions between muscarinic antagonists, adrenergic agonists and NMDA antagonists with respect to locomotor stimulatory effects in monoamine-depleted mice

The purpose of the present investigation was to study the effects of simultaneous manipulations of central cholinergic, adrenergic and glutamatergic systems on locomotion in an animal model of Parkinson's disease. Mice were deprived of their monoamine stores by pretreatment with the monoamine depleter reserpine and the catecholamine synthesis inhibitor alpha-methyl-p-tyrosine, given 18 h and 60 min, respectively, before the acute experiment. Traditionally, only dopaminergic agonists have been shown to reverse the akinesia thus produced. However, in the present study it is demonstrated that if a muscarine receptor antagonist (atropine or biperiden) is combined with an alpha-adrenergic agonist/alpha-adrenergic agonist precursor (clonidine or L-alpha-methyl-dopa), a marked locomotor stimulation can be achieved, although either agent given alone is ineffective. Adding an NMDA antagonist (MK-801, ketamine or SDZ EAA 494) to the combination biperiden + clonidine resulted in further potentiation of the locomotor stimulatory effects.

High dose anticholinergic therapy (biperiden) in dystonia

We studied the effect of biperiden in the treatment of dystonia in six patients aged 15-30 years. Five patients had generalized and one patient had segmental dystonia. Biperiden was started at a dose of 2 mg/day and was gradually increased to 40 mg/day in a few weeks. All patients had clinically significant response in varying degrees after a mean follow up of 1.9 years. Three patients showed considerable or dramatic benefit. The 40 mg/day was generally well tolerated. High dose anticholinergic therapy is effective in the management of torsion dystonia.