Employment status and health related quality of life among Hodgkin-lymphoma survivors'- results based on data from a major treatment center in Hungary

BACKGROUND

Due to risk and response adapted treatment strategies, more than 80% of newly diagnosed classical Hodgkin lymphoma (HL) patients can be cured, and become long-term survivors. However, a high proportion of survivors suffer from treatment-related long-term side effects such as secondary malignancy, organ failure, persistent fatigue and psychological distress. The aim of this study was to evaluate psychological distress and its risk factors among our HL survivors.

METHODS

One hundred sixty-three (50% female) adult HL survivors were contacted between January 1, 2012 and march 31, 2015 in our outpatient centre. The patients were asked to complete a standardized, validated, self-administered Hungarian questionnaire with demographic questions and the following scales: Hospital anxiety and depression scale (HADS14), general health questionnaire (GHQ12), sense of coherence (SOC13) perceived stress scale (PSS4), dysfunctional attitude scale (DAS17). Disease and treatment data were acquired from hospital records.

RESULTS

Majority of HL survivors are in early adulthood, our most important goal should be to return them to normal life after their lymphoma is cured. The employment status at the time of survey seemed to be crucial so patients were divided into either active (n = 93) or inactive (n = 47) group. Retired survivors (n = 19) were excluded from the subgroup analysis. Psychological distress was significantly lower in active patients. Multiple logistic regression analysis showed significant differences between the inactive and active subgroups, such as age at diagnosis (≥30 years or below, p = 0.001), education level (below college vs. college, p = 0.032) and treatment related long-term side effects (yes vs. no, p < 0.001). Predictors for treatment-related long-term side effects are female gender (p = 0.011), chemotherapy protocol (ABVD vs. other, p < 0.001).

CONCLUSIONS

Our data suggest that employment status and treatment-related long-term side effects play a critical role in the health related quality of life outcome among Hungarian HL survivors.

Clinical Decision Making and Mental Health Service Use Among Persons With Severe Mental Illness Across Europe

OBJECTIVE

The study explored relationships between preferences for and experiences of clinical decision making (CDM) with service use among persons with severe mental illness.

METHODS

Data from a prospective observational study in six European countries were examined. Associations of baseline staff-rated (N=213) and patient-rated (N=588) preferred and experienced decision making with service use were examined at baseline by using binomial regressions and at 12-month follow-up by using multilevel models.

RESULTS

A preference by patients and staff for active patient involvement in decision making, rather than shared or passive decision making, was associated with longer hospital admissions and higher costs at baseline and with increases in admissions over 12 months (p=.043). Low patient-rated satisfaction with an experienced clinical decision was also related to increased costs over the study period (p=.005).

CONCLUSIONS

A preference for shared decision making may reduce health care costs by reducing inpatient admissions. Patient satisfaction with decisions was a predictor of costs, and clinicians should maximize patient satisfaction with CDM.

[Ketamine administration in case of severe, therapy resistant depressed patient, case report]

Objective - In our case report we present the treatment of a female patient suffering from therapy resistant depression. This procedure is not in practice in Hungary at present, the aim of our work to reproduce the findigs of international studies in domestic circumstances. Matter - Major depression is a common, chronic and severe mental disorder, with 16.2% lifetime prevalence. Many international randomized, placebo controlled trials found administration of ketamine infusion effective in depressed patients. Methods - Since ketamine is an anesthetic agent, its administration was performed in the post-operative monitoring room of our hospital operating-room, supervised by an anesthesiologist. According to formerly published data, a dose of 0.5 mg/kg of body weight was administered intravenously in 40 minutes by perfusor. The drug was administered in a same manner fifteen days later. Subject - The patient was admitted to our inpatient ward with severe depression. During two months of combined antidepressant therapy her condition has not improved significantly. Approval for off label drug indication was granted with urgency by the National Institute of Quality and Organizational Development in Healthcare and Medicines. Results - During the two treatments the Hamilton Depression Rating Scale 21 items rating scale score was reduced to 8 from the baseline 28, the Hamilton Anxiety Rating Scale score was reduced to 6 from 25, Beck Depression Inventory was reduced to 9 from 20. Upon administration of the drug no severe adverse event was detected, the mild dissociative state related to ketamine was ceased in a short period of time. Discussion - With administration of 0.5 mg/kg ketamine the authors managed to achieve rapid improvement in a therapy resistant depressed patient, without permanent side effects. Our future plan is to repeat the use of the drug within a double-blind, placebo controlled trial in order to prove its efficacy in hospital settings.

UNANSWERED QUESTIONS IN THE TRANSCRANIAL MAGNETIC STIMULATION TREATMENT OF PATIENTS WITH DEPRESSION

According to the WHO fact sheet depression is a common mental disorder affecting 350 million people of all ages worldwide. Transcranial Magnetic Stimulation (TMS) is a technique which allows the investigator to stimulate and study cortical functions in healthy subjects and patients suffering from various mental and neurological disorders. In the early 1990s, studies revealed that it is possible to evoke long term mood changes in healthy volunteers by rapid rate repetitive, TMS (rTMS) over the frontal cortex. Subsequent studies involving depressed patients found frontal cortical rTMS administered daily to be clinically effective. In the past two decades, numerous trials examined the therapeutic potential of rTMS application in the treatment of mood disorders with constantly evolving treatment protocols. The aim of this paper is to review the literature of the past two decades, focusing on trials addressing the efficacy and safety of rTMS in depressed patients. Our primary goal is to evaluate the results in order to direct future studies which may help investigators in the development of treatment protocols suitable in hospital settings. The time is not far when TMS devices will be used routinely by practitioners primarily for therapeutic purpose rather than clinical research. To our knowledge, a widely accepted "gold standard" that would offer the highest efficacy, with the best tolerability has not been established yet. In order to approach this goal, the most important factors to be addressed by further studies are: localization, frequency, intensity, concurrent medication, maintenance treatments, number of pulses, trains, unilateral, or bilateral mode of application.

Liver enzyme abnormalities during antipsychotic treatment: a case report of risperidone-associated hepatotoxicity

BACKGROUND

Drug-induced liver enzyme abnormalities may indicate hepatic injury. Antipsychotic drugs also may cause increase in the liver enzymes and serum bilirubin levels. The present report evaluates the case of a patient with risperidone-associated hepatocellular damage.

CASE SUMMARY

A 19-year-old Caucasian man was admitted to the Department of Psychiatry with paranoid schizophrenia and risperidone was administered in a gradually increasing dose up to 8 mg/day. After 3 weeks of treatment, he experienced asthenia and weight loss. The level of aspartate aminotransferase was 283 IU/L (normal: <30 IU/L), and the alanine aminotransferase level was 778 IU/L (normal: <36 IU/L). Treatment with risperidone was immediately discontinued. Six days after drug withdrawal, the alanine aminotransferase level fell more than 50%, and a complete return to normalcy was seen within 2 months.

RESULTS

In the present case, a possible causal association between risperidone and hepatocellular damage has been observed due to the temporal relationship between the administration of the drug and the onset of hepatic abnormalities, and a following rapid recovery after stopping the drug. As the hepatic damage could be related to the plasma concentration of risperidone which is highly influenced by the hepatic enzyme CYP2D6, the patient was genotyped for CYP2D6. He was classified as homozygous wild type for CYP2D6.

CONCLUSIONS

The risk for developing hepatotoxicity during risperidone therapy cannot be supported by the patient CYP2D6 genotype. In clinical practice, it may be recommended to obtain baseline liver function tests before starting risperidone and regular screening for liver enzyme changes during therapy.

Investigating the state-like and trait-like characters of social cognition in schizophrenia: a short term follow-up study

BACKGROUND AND OBJECTIVES

Controversial findings exist in the literature regarding the state- and trait-like characters of social cognition in schizophrenia. In order to explore the relationship of social cognition with symptom severity in the present study, Theory of mind (ToM) and emotion recognition were tested in an acute phase and later in a clinically stable phase in patients.

METHODS

ToM and emotion recognition abilities were examined by using the Reading the Mind in the Eyes Test (RMET) and the Ekman 60 Faces Test (FEEST) in 43 patients with schizophrenia and 41 healthy controls. Research diagnoses were based on SCID interviews. Symptom severity in patients was assessed by the Positive and Negative Syndrome Scale (PANSS).

RESULTS

ToM and emotion recognition deficits improved in the clinically stable phase compared to relapse, but were still found to be impaired compared to healthy controls. Negative symptom severity showed strong correlation with emotion recognition and ToM at both visits.

CONCLUSIONS

Both ToM and emotion recognition fluctuated together with symptom severity, which confirmed the "state-like" component of these abilities. Our results, taken together with the findings of previous investigations show that social cognition deficits in schizophrenia have both state-like and trait-like components.

Pharmacogenetics of clinical response to risperidone

Despite risperidone's proven safety and efficacy, existing pharmacogenetic knowledge could be applied to improve its clinical use. The present work aims to summarize the information about genetic polymorphisms affecting risperidone adverse reactions and efficacy during routine clinical practice. The most relevant genes involved in the metabolism of the drug (i.e., CYP2D6, CYP3A and ABCB1) appear to have the greatest potential to predict differences in plasma concentrations of the drug and its interactions, but also relate to side effects, such as neuroleptic syndrome, weight gain or polydipsia. Other genes that have been found in association at least twice with any adverse reactions including metabolic changes, extrapyramidal symptoms or prolactine increase are: 5HT2A; 5HT2C; 5HT6; DRD2; DRD3; and BDNF. Some of these genes (5HTR2A, DRD2 and DRD3), along with 5-HTTLPR and COMT, have also been reported to be related with negative clinical outcomes. However, there is not yet enough evidence to support their routine screening during clinical practice.

Automated Neuropsychological Test Battery in depression -- preliminary data

AIMS

Studies have demonstrated neuropsychological deficits across a variety of cognitive domains in patients with major depressive disorder (MDD) during acute episode. However, limited data are available concerning whether these abnormalities persist in the remission phase.

METHODS

In the present study CANTAB (Cambridge Automated Neuropsychological Test Battery) was used to evaluate the cognitive impairment associated with depression during acute episode and in remission. 25 patients with MDD during an acute episode and 11 patients also during remission were tested with CANTAB.

RESULTS

During the acute episode, Delayed matching to sample, Paired associate learning, Spatial recognition memory, Rapid visual processing and Visuospatial planning were impaired. In remission the improvement of visual learning ability, spatial recognition memory, psychomotor speed, and executive function was observed.

CONCLUSIONS

The results suggest that MDD is associated with neurocognitive dysfunctions in different domains, the most prominent deficit was found in the Paired associate learning test, which requires both the elaboration of "frontal strategies" and the "mnemonic processes". Cognitive impairment was found to improve partly in remission, suggesting that an individual's current mood interacts with the ability to perform a cognitive task. Besides these state markers, trait deficits are important because cognitive impairments which do not improve in remission might serve as endophenotypes of depression.

[P300 in mild cognitive impairment and in dementia]

OBJECTIVES

The late component of the event-related potential (ERP), P300 is a marker for cognitive brain functions. The objective of this study was to examine P300 parameters in dementia and in mild cognitive impairment (MCI), to examine whether there is a correlation between the changes in P300 parameters and the type and severity of dementia, and to determine P300 abnormalities in MCI in relation to the presence/absence of CT/MRI abnormalities.

METHOD

Auditory event-related potentials, P300 were recorded in 28 MCI patients (14 of them with normal CT/MRI findings and 10 subjects with mild ventricular enlargement). In another group of patients, 31 demented patients were examined, of whom 17 patients were diagnosed with Alzheimer's dementia (AD), and 14 patients with vascular dementia (VD). Forty healthy volunteers served as the control group.

RESULTS

Mean P300 latency was significantly increased for both demented patient-groups. We found that prolongation of P300 latency was correlated with the severity of dementia. Mean P300 amplitude was significantly decreased in both groups of demented patients. In MCI, the mean latency of P300 was significantly longer among patients with mild cerebral atrophy compared to control volunteers and no significant changes were found for MCI patients with normal CT/MRI findings. Mean P300 amplitude was decreased only in demented patients.

CONCLUSIONS

The prolongation of P300 latency was significant among patients with both vascular and Alzheimer's dementia, and also among MCI patients with mild cerebral atrophy. The severity of dementia is positively correlated with P300 latency; however, this prolongation is independent of the type of dementia. The structural brain changes in MCI are related to P300 latency prolongation and thus may indicate an increased risk for developing dementia in MCI patients.

Automated Neuropsychological Test Battery (CANTAB) in mild cognitive impairment and in Alzheimer's disease

Neuropsychological deficits, such as poor episodic memory, are consistent features of mild cognitive impairment and also that of early stage of dementia. The aim of the present study was to detect cognitive dysfunction among patients with Alzheimer's disease or with mild cognitive impairment (MCI), which refers to a transitional state between the cognition of normal aeging and mild dementia regarded as a high-risk condition for the development of clinically probable Alzheimer's disease (AD). Computerized tests of memory, attention and executive functions were studied in groups of AD subjects (n=15) and MCI subjects (n=25). On all measures, the performance of the AD group was significantly weaker compared to healthy individuals or to the MCI group. The performance of both the AD and MCI patients in the Paired Associate Learning test was significantly impaired, which may suggest that MCI patients are already in the early stages of the disease.

Antipsychotic drugs and QTc prolongation: the potential role ofCYP2D6genetic polymorphism

Although the most common, and usually serious, side effects of first-generation (or typical) antipsychotic drugs, such as Parkinsonism, dystonias and tardive dyskinesia, were known from early times, their cardiovascular safety was not properly in the focus of treatment management. The growing evidence of these drug-related cardiac changes and the appearance of potentially fatal dysrhythmias have increased the interest on their safety profile. Thus, the introduction of the new second-generation (atypical) antipsychotic drugs put emphasis on the preregistration evaluation of the potential cardiac side effects and electrocardiogram predictors (QT interval lengthening). In spite of this, these drugs do not appear to be exempt from these potential risks. The present review summarizes up-to-date knowledge about the cardiac safety of antipsychotic drugs, and analyses the role of drug metabolic processes (CYP2D6 genetic polymorphism) in the complex pathophysiology of the phenomenon. In addition, some recommendations are formulated.

Clinical Implications of CYP2D6 Genetic Polymorphism During Treatment with Antipsychotic Drugs

CYP2D6 is described as the most relevant enzyme in the metabolism of many antipsychotic drugs. Its contribution to the interindividual differences in drug response is reviewed here highlighting its role in the kinetics of antipsychotic drugs and the occurrence of drug interactions. The activity of CYP2D6 is inherited as a monogenetic trait and the CYP2D6 gene appears highly polymorphic in humans. The polymorphic alleles may lead to altered activity of the CYP enzymes causing absent, decreased (poor), or increased (ultrarapid) metabolism that in turn influence the disposition of the antipsychotic drugs. Antipsychotic drug biotransformation is mainly determined by genetic factors mediating CYP2D6 gene polymorphism, however the importance of environmental factors (dietary, smoking, diseases, etc.) is also recognized. Additionally, the potential interaction between CYP2D6 and the endogenous metabolism must be taken into consideration. The present review summarizes the relevance of physiological and environmental factors in CYP2D6 hydroxylation capacity, the inhibition of CYP2D6 activity during treatment, the use of drug/metabolite ratio as a tool to evaluate CYP2D6 hydroxylation capacity in a patient, and the relevance of CYP2D6 for drug plasma concentration and for QTc interval lengthening during treatment with antipsychotic drugs.

Brain blood flow changes measured by positron emission tomography during an auditory cognitive task in healthy volunteers and in schizophrenic patients

OBJECTIVE

Cognitive deficit is an essential feature of schizophrenia. One of the generally used simple cognitive tasks to characterize specific cognitive dysfunctions is the auditory "oddball" paradigm. During this task, two different tones are presented with different repetition frequencies and the subject is asked to pay attention and to respond to the less frequent tone. The aim of the present study was to apply positron emission tomography (PET) to measure the regional brain blood flow changes induced by an auditory oddball task in healthy volunteers and in stable schizophrenic patients in order to detect activation differences between the two groups.

METHOD

Eight healthy volunteers and 11 schizophrenic patients were studied. The subjects carried out a specific auditory oddball task, while cerebral activation measured via the regional distribution of [15O]-butanol activity changes in the PET camera was recorded.

RESULTS AND DISCUSSION

Task-related activation differed significantly across the patients and controls. The healthy volunteers displayed significant activation in the anterior cingulate area (Brodman Area - BA32), while in the schizophrenic patients the area was wider, including the mediofrontal regions (BA32 and BA10). The distance between the locations of maximal activation of the two populations were 33 mm and the cluster size was about twice as large in the patient group.

CONCLUSIONS

The present results demonstrate that the perfusion changes induced in the schizophrenic patients by this cognitive task extends over a larger part of the mediofrontal cortex than in the healthy volunteers. The different pattern of activation observed during the auditory oddball task in the schizophrenic patients suggests that a larger cortical area - and consequently a larger variety of neuronal networks--is involved in the cognitive processes in these patients. The dispersion of stimulus processing during a cognitive task requiring sustained attention and stimulus discrimination may play an important role in the pathomechanism of the disorder.

Reduced completed suicide rate in Hungary from 1990 to 2001: relation to suicide methods

BACKGROUND AND METHOD

Changes in the rate of completed suicides and in the suicide methods used in Hungary between 1990 and 2001 were evaluated using the database of the Hungarian Central Statistical Office.

RESULTS

During this period of time, the suicidal mortality rate decreased by 27.9%. A major part (62%) of this decrease was due to the less frequent use of poisonous substances and drug overdose, particularly of psychotropics.

CONCLUSION

Beside the more widespread treatment of depression and other mental disorders, the improved safety of pharmacotherapy and the removal of the most toxic pesticides and chemicals from everyday use might have contributed to the reduction of the suicide rate in Hungary.

[Cognitive functions in prepsychotic and negative-symptom schizophrenic patients]

BACKGROUND

Relationship between schizophrenia and cognitive functions has been reported by several studies. Our work group examined the changes of cognitive functions in prepsychotic patients without any relevant psychiatric disorder in their anamnesis, and also in schizophrenic patients with predominantly negative symptoms.

METHODS

Measures were carried out by Cambridge Neuropsychological Test Automated Battery (CANTAB), a complex computer-based test battery of 13 tests covering a wide range of cognitive functions. 11 prepsychotic (9 male, 2 female) and 14 negative-symptom schizophrenic patients (all male) took part in the study.

RESULTS

Prepsychotic patients showed significant (p < 0.05) impairment in the tests of visual memory, spatial recognition memory, spatial working memory and sustained attention. In patients with negative-symptoms significant deficits were also found (p < 0.05) in the delayed matching to sample, the working memory test, and in the intra-extradimensional shift--an analogue of Wisconsin Card Sorting Test.

CONCLUSION

The present results show CANTAB may be a useful tool to detect the emergence of psychosis in an early phase, and also it has been found that in schizophrenic patients with predominantly negative symptoms further areas of cognition are also affected. The results may provide a better understanding about the background of the disorder, and the early recognition of the cognitive deficits may help to initiate a specific therapy in proper time. This could result in the slowing of the progression and an improved chance of recovery.

Cognitive functions in prepsychotic patients

OBJECTIVE

Cognitive dysfunctions are now widely understood as an essential feature of schizophrenia. A great number of cognitive disturbances have been described in drug-naive first-episode patients as well. The full-blown psychotic symptoms are usually preceded by a longer prodromal period, in which non-specific psychological disturbances are already present. The late prodromal phase is also coined as the prepsychotic state, with attenuated, isolated psychotic symptoms. The aim of the present study was to detect cognitive dysfunctions among young adults at the prepsychotic stage with the use of a standardized computer based cognitive test battery.

METHOD

Eleven (9 men, 2 women) young Hungarian adults referred to the Outpatient Clinic of the Department of Psychiatry at the University of Debrecen were studied. The patients were re-evaluated for psychotic symptoms after 12 months. The patients had no history of psychiatric disorders or psychotic episodes and were referred by general practitioners on account of non-specific emotional or behavioural abnormalities. The subjects were asked to perform a series of 13 computerized neuropsychological tests of the Cambridge Neuropsychological Test. The performance of the patients were compared to that of the standardized database of the Cambridge Neuropsychological Test.

RESULTS AND DISCUSSION

The performance of the prepsychotic patients was significantly lower compared to the healthy individuals in the paired associate learning (PAL, p<0.001), Spatial recognition memory (SRM, p<0.05), Rapid visual processing (RVP, p<0.05), and Spatial working memory (SWM, p<0.05) tests.

CONCLUSION

Cognitive deficits were found mainly in attentional, frontal and prefrontal cognitive functions. These impairments may be present at the early stages of the development of psychosis and the standardized cognitive test battery (CANTAB) might be a useful tool for the detection of early cognitive impairments and provide a rationale for early intervention in individuals at risk of developing psychosis.

Determination of debrisoquine and 4-hydroxydebrisoquine by high-performance liquid chromatography: application to the evaluation of CYP2D6 genotype and debrisoquine metabolic ratio relationship

The drug-metabolizing cytochrome P450 (CYP) enzyme CYP2D6 is involved in the metabolism of several clinically important drugs. So far more than 50 different

The Role of Cytochrome P450 Enzymes in the Metabolism of Risperidone and Its Clinical Relevance for Drug Interactions

In the recent years it has been increasingly recognized that pharmacogenetical factors play an important role in the drug treatment. These factors may influence the appearance of side-effects and drug interactions due to interindividual differences in the activity of metabolizing enzymes. Risperidone in humans is mainly metabolized to 9-hydroxyrisperidone by the polymorphic cytochrome enzyme P450 2D6 (CYP2D6). Plasma concentrations of risperidone and 9-hydroxyrisperidone show large interindividual variability, which may be partly related to the activity of the CYP2D6 enzyme. Around seven percent of Caucasians have a genetically inherited impaired activity of the CYP2D6 enzyme. Debrisoquine metabolic ratio (a marker of CYP2D6 activity) and the number of CYP2D6 active genes have been related to risperidone plasma concentrations among patients during steady-state conditions. A large number drugs have been described to be metabolized by CYP2D6, and it is therefore important to evaluate the clinical significance of the impaired metabolism and possible drug interactions on the enzyme. Since risperidone/9-hydroxyrisperidone ratio strongly correlates with CYP2D6 enzyme activity and the number of CYP2D6 active genes, thus it might be a useful tool in clinical practice to estimate the possible risk of drug interactions due to impaired CYP2D6 enzyme activity. CYP3A4 is the most abundant drug metabolizing enzyme in humans, and in vitro and in vivo results suggest also a role for the enzyme in risperidone metabolism. The consideration of the implication of cytochrome P450 enzymes in risperidone metabolism may help to individualize dose schemes in order to avoid interactions and potentially dangerous side-effects, such us QTc interval lengthening among patients with cardiac risk factors.

[Effect of atypical antipsychotics on metabolism]

The metabolic effect of atypical antipsychotic drugs may manifest itself in weight gain, disturbances in glucose homeostasis and dyslipidemia. One confounding factor is that psychotic disorders themselves make the patients prone to specific metabolic changes. Nevertheless clinical studies have confirmed that atypical anti-psychotic drugs have a different metabolic effect. In the present prospective case-series, four male antipsychotic drug-naive psychiatric patients without any familial history of metabolic disorder were studied. The patients received risperidone or olanzapine monotherapy for 12 weeks; weight, plasma levels of triglyceride, cholesterol, HDL, and fasting glucose were measured in every 4th week. In two patients, oral glucose tolerance test (OGTT) was also performed at days 0 and 56. The average weight gain during the 12-week period was 12%. The cholesterol and triglyceride plasma concentrations were also elevated. The fasting glucose levels did not change during the observation period. In the OGTT performed in two patients, normal fasting glucose and insulin plasma levels were observed after 8 weeks; however, the plasma insulin concentrations were highly elevated after glucose intake, which may suggest the presence of insulin resistance. Our preliminary results confirmed the previous results on the metabolic effect of atypical anti-psychotic drugs, which may lead to metabolic syndrome. The regular control of the metabolic laboratory parameters, early intervention and the modification of the atypical antipsychotic treatment may help to avoid this adverse effect of the drugs.

QTc interval, CYP2D6 and CYP2C9 genotypes and risperidone plasma concentrations

The role of certain drug metabolizing enzymes in cardiotoxicity, such as CYP2D6 for thioridazine, has been suggested. Risperidone has been shown to inhibit the delayed rectifier leading to lengthening of cardiac repolarization. The heart-rate corrected QT (QTc) interval lengthening has been reported in psychiatric patients receiving risperidone under steady-state conditions. CYP2D6 is involved in the metabolism of risperidone to 9-hydroxy (OH)-risperidone. CYP2C9 enzyme is also involved in the metabolism of several psychotropic drugs, although there are no data about its implication in risperidone metabolism. The present study aimed to evaluate the influence of CYP2D6 and CYP2C9 genotypes, and plasma concentrations of risperidone and 9-OH-risperidone on the QTc interval in patients under steady-state conditions. The relevance of CYP2D6 and CYP2C9 genotypes on risperidone metabolism was also analysed. Thirty-five White European psychiatric patients receiving risperidone monotherapy were studied. QTc interval was longer (p < 0.05) in subjects with one active CYP2D6 gene compared to those with two. The number of CYP2D6 active genes was related to the dose-corrected plasma concentration of risperidone (p < 0.05), the active moiety (risperidone plus 9-OH-risperidone) (p < 0.05) and the risperidone/9-OH-risperidone ratio (p < 0.05). CYP2C9 genotypes were not related to plasma concentrations of risperidone or 9-OH-risperidone, nor QTc interval. The results suggest that CYP2D6, but not CYP2C9, may be related to QTc lengthening during treatment with risperidone. The effect of the CYP2D6 genotype in risperidone metabolism is also shown.

Reproducibility over time of the urinary diclofenac/4'-OH diclofenac ratio among different CYP2C9 genotypes

Diclofenac has been used for the evaluation of CYP2C9 activity in vitro as well as in vivo with varying results. The present study was aimed at evaluating the reproducibility of the urinary diclofenac/4'-OH diclofenac ratio among different CYP2C9 genotypes in healthy volunteers. The study of CYP2C9 genotypes in the family of a CYP2C9*3/*3 subject is also reported. The urinary diclofenac/4'-OH diclofenac ratio was determined on two occasions within a period of 9-12 months, and was found to be correlated (r = 0.83, p < 0.05). The mean (+/- SD) of diclofenac/4'-OH diclofenac ratio was 1.5 times higher among subjects carrying CYP2C9*3 allele (CYP2C9*1/*3 and CYP2C9*2/*3 genotypes) (0.91 +/- 0.28), compared to CYP2C9*1/*1 subjects (0.60 +/- 0.11). The results show that the urinary diclofenac/4'-OH diclofenac ratio might be used to study CYP2C9 in humans. The data agree with previous studies showing that the CYP2C9*3 allelic variant seems to cause a decreased CYP2C9 hydroxylation capacity.

Relationship between Haloperidol Plasma Concentration, Debrisoquine Metabolic Ratio,CYP2D6andCYP2C9Genotypes in Psychiatric Patients

BACKGROUND

Around seven percent of Caucasians are poor metabolizers of cytochrome P450, CYP2D6 due to genetically impaired activity of the enzyme. Haloperidol in vitro and in vivo inhibits the activity of CYP2D6 and also the involvement of the enzyme in haloperidol metabolism has been reported. The present study was aimed to evaluate the possible inhibition of CYP2D6 during haloperidol treatment, and to determine the effect of CYP2D6 and CYP2C9 genotypes on the plasma concentration of haloperidol.

METHODS

Thirty Caucasian psychiatric patients under haloperidol monotherapy were studied. CYP2D6 activity was evaluated by the debrisoquine metabolic ratio (MR), subjects with MR > 12.6 were named as poor metabolizers. Haloperidol plasma concentration was determined by high performance liquid chromatography.

RESULTS

The number of patients with debrisoquine MR > 12.6 was higher than the expected comparing to healthy volunteers (13 % vs. 6.6 %, respectively). Debrisoquine MR was correlated with the dose of haloperidol (r = 0.40, p < 0.05), and also with the plasma concentration (r = 0.58, p < 0.001). Additionally, three patients comedicated with inhibitors of CYP2D6 were studied, all of them had a debrisoquine MR > 12.6, however only one was genetically poor metabolizer of CYP2D6. CYP2D6 and CYP2C9 genotypes were not related to the dose or plasma concentration of haloperidol.

CONCLUSIONS

The present data support the dose-dependent inhibitory effect of haloperidol on CYP2D6, and the influence of this enzyme activity on haloperidol plasma concentration under steady-state conditions. The inhibitory effect of haloperidol on CYP2D6 enzyme activity may result in drug interactions and unexpected high plasma concentrations when drugs metabolized by the same enzyme are given concomitantly with haloperidol.

Effect of CYP2D6 and CYP2C9 genotypes on fluoxetine and norfluoxetine plasma concentrations during steady-state conditions

OBJECTIVES

CYP2D6 drug-metabolising enzyme has been shown to be involved in fluoxetine metabolism in vitro and in vivo. CYP2C9 has also been shown to influence the metabolism of fluoxetine in vitro; however, this relationship has not been studied in humans. The aim of the present study was to evaluate the influence of CYP2D6 and CYP2C9 genotypes on the plasma concentration of fluoxetine and norfluoxetine in psychiatric patients during steady-state conditions.

METHODS

White European psychiatric patients ( n=64) receiving antidepressant monotherapy with fluoxetine were studied. CYP2D6 and CYP2C9 genotypes were determined by polymerase chain reaction-specific methods. The plasma concentrations of fluoxetine and its metabolite, norfluoxetine, were measured by high-performance liquid chromatography.

RESULTS

The dose-corrected plasma concentrations of fluoxetine were related ( P<0.01, r=-0.36) to CYP2D6 genotypes (number of active genes). The fluoxetine/norfluoxetine ratio also correlated ( P<0.01, r=-0.39) with the number of active CYP2D6 genes. Among patients with two CYP2D6 active genes, the dose-corrected plasma concentrations of fluoxetine and active moiety (fluoxetine plus norfluoxetine) were significantly ( P<0.05) higher in the CYP2C9*1/*2 and CYP2C9*1/*3 genotype groups than in CYP2C9*1/*1. However, dose-corrected (C/D) plasma concentrations of fluoxetine, active moiety and fluoxetine/norfluoxetine ratios were not highly different in the individuals with two mutated alleles as compared with those heterozygous for *2 or *3.

CONCLUSION

The present results show that CYP2D6 and potentially CYP2C9 genotypes seem to influence fluoxetine plasma concentration during steady-state conditions in patients.

CYP2C9 gene and susceptibility to major depressive disorder

Alteration of monoaminergic neurotransmission has been implicated in the pathophysiology of mood disorders, and CYP2C9 enzyme activity has been shown to be modulated by serotonin in vitro. The present study was aimed at analysing the frequency of CYP2C9 alleles (*1, *2, *3) among patients suffering from major depressive disorder. In all, 70 such suffering psychiatric outpatients were studied. The CYP2C9 genotypes were determined by allele-specific PCR. The CYP2C9*3 allele frequency was higher (P<0.01) among the patients suffering from major depression than in a population of 89 schizophrenic patients (odds ratio=3.3) and 138 healthy volunteers (odds ratio=2.8). The results suggest that CYP2C9 genetic polymorphism may be related to a major depressive disorder due to an alteration in endogenous metabolism, although a linkage between CYP2C9 and some other gene related to depression cannot be ruled out.

CYP2C9 genotypes and diclofenac metabolism in Spanish healthy volunteers

OBJECTIVE

This study analyzed the frequency of CYP2C9 variant alleles and evaluated the impact of CYP2C9 genotype on diclofenac metabolism in a Spanish population.

METHODS

Diclofenac hydroxylation capacity was studied in a population of 102 healthy volunteers. After a single oral dose of 50 mg diclofenac the 0- to 8-h urinary concentrations of diclofenac and its main metabolites, 4'-hydroxy (OH), 3'-OH and 5-OH diclofenac were analyzed by high-performance liquid chromatography. CYP2C9 genotyping for the variant alleles CYP2C9*2 and *3 was carried out with PCR-RFLP.

RESULTS

The frequencies of CYP2C9*1, *2, and *3 alleles were 0.74 (95%CI: 0.68-0.80), 0.16 (95%CI: 0.11-0.21) and 0.10 (95%CI: 0.06-0.15), respectively, among the 102 Spaniards studied. The diclofenac/4'-OH diclofenac urinary ratio, but not the diclofenac/3'-OH diclofenac and diclofenac/5-OH diclofenac ratios, was related to CYP2C9 genotype. The diclofenac/4'-OH ratio was significantly higher among subjects with CYP2C9*1/*3 (0.83+/-0.4, n=14, 95% CI for the difference: 0.02-0.4) and CYP2C9*2/*3 (1.10+/-0.5, n=4, 95% CI for the difference: 0.16-0.8) genotypes compared to CYP2C9*1/*1 (0.62+/-0.3, n=59) and approximately threefold higher (1.8) in the only subject homozygous for CYP2C9*3 variant.

CONCLUSIONS

The frequencies of CYP2C9*1, *2, and *3 alleles in the Spanish population reported here were similar to those found in the previously studied white European populations, and different of the previously reported in another Spanish population. CYP2C9*3 allele seems to influence the 4'-hydroxylation of diclofenac, although there is a large overlapping in the urinary metabolic ratio between the genotype groups studied

Analysis of diclofenac and its metabolites by high-performance liquid chromatography: relevance of CYP2C9 genotypes in diclofenac urinary metabolic ratios

In humans, diclofenac is metabolised to 4'-hydroxy (OH), 3'-OH and 5-OH metabolites. The polymorphic CYP2C9 is involved in the metabolism of diclofenac to 4'-OH diclofenac and 3'-OH diclofenac. The aim of the present study was to develop a high-performance liquid chromatographic method to simultaneously measure diclofenac and its metabolites in urine, suitable for metabolic studies. After liquid-liquid extraction the compounds were separated in a reversed-phase column and measured by ultraviolet absorption at 282 nm. For all compounds intra-day and inter-day variations were less than 7%, and the limits of quantitation were 0.25 mg/l. No analytical interference with endogenous compounds was found. The relationship between diclofenac metabolic ratios among different CYP2C9 genotypes is reported. The CYP2C9*3/*3 subject had the highest diclofenac/4'-OH ratios. However no difference was found between CYP2C9*2/*2 and *1/*1 genotypes. The chromatographic method developed was sensitive and reliable for the measurement of diclofenac and its metabolites simultaneously in human urine, and is suitable for use in diclofenac metabolism studies.

Thioridazine steady-state plasma concentrations are influenced by tobacco smoking and CYP2D6, but not by the CYP2C9 genotype

BACKGROUND

Approximately 7% of Caucasians have genetically impaired activity of the cytochrome P450 enzyme CYP2D6 and are classified as poor metabolizers (PM). The disposition of thioridazine has been related to the CYP2D6 phenotype. The present study aimed to evaluate the influence of CYP2D6 and CYP2C9 genotypes, and tobacco smoking on steady-state thioridazine plasma levels.

METHODS

Seventy-six Caucasian psychiatric patients receiving thioridazine monotherapy were studied. Debrisoquine metabolic ratio (MR) and steady-state plasma levels of thioridazine and its metabolites, mesoridazine and sulforidazine, as well as CYP2D6 (in 74 patients) and CYP2C9 (in 63 patients) genotypes were determined.

RESULTS

The median dose-corrected, steady-state plasma concentrations (C/D) of thioridazine were related to the number of functional CYP2D6 alleles ( P<0.01), being 15.2, 7.2, 4.0, 4.2 nmol/l per milligram in subjects with no, one, two, and three or more functional CYP2D6 genes, respectively. No significant differences were found in the C/Ds of mesoridazine or sulforidazine. No relationship was found between CYP2C9 genotype and plasma levels of thioridazine or its metabolites. The median C/D of thioridazine was significantly ( P<0.001) lower in smokers (4.0 nmol/l per milligram, range: 1.0-15.5; n=58) than in nonsmokers (7.4 nmol/l per milligram, range: 2.8-23.6; n=18). Also, the C/Ds of mesoridazine and sulforidazine were lower in smokers ( P<0.01). The plasma thioridazine/mesoridazine ratio significantly correlated with the debrisoquine MR ( r(2)=0.30, P<0.001).

CONCLUSION

The results show that the plasma concentrations of thioridazine and its metabolites are influenced by tobacco smoking and the CYP2D6 genotype, and support the dose-dependent inhibition of CYP2D6 by thioridazine. CYP2C9 does not play an important role in thioridazine metabolism.

Determination of fluoxetine and norfluoxetine in human plasma by high-performance liquid chromatography with ultraviolet detection in psychiatric patients

A rapid high-performance liquid chromatographic method is described for the simultaneous determination of the widely used antidepressant drug, fluoxetine and its principal metabolite norfluoxetine in plasma. After liquid-liquid extraction the compounds were separated in a reversed-phase column and assayed by ultraviolet absorption at 226 nm. The analytical interference from psychoactive drugs and their metabolites was also studied. The extraction recoveries were 93 and 87% for norfluoxetine and fluoxetine, respectively. The limit of quantitation under the described conditions was 14 nmol/l for both compounds. The method was found to be reproducible with coefficients of variation less than 10%. A great variability in plasma concentrations of fluoxetine and norfluoxetine as well as in fluoxetine/norfluoxetine ratios was found among the 29 patients studied. This result suggests the implication of genetically polymorphic enzymes, presumably CYP2D6, CYP2C9 and CYP2C19 in the metabolism of fluoxetine to norfluoxetine. Therapeutic drug monitoring should thus be useful in patients treated with regular doses.

Determination of risperidone and 9-hydroxyrisperidone in human plasma by liquid chromatography: application to the evaluation of CYP2D6 drug interactions

A high-pressure liquid chromatography with ultra-violet detection method for the simultaneous determination of risperidone and 9-hydroxyrisperidone in plasma after liquid-liquid extraction has been developed. The limit of quantitation was 5 nmol/L, and the inter-day coefficient of variation was less than 8% for both compounds. The mean recoveries of risperidone and 9-hydroxyrisperidone added to plasma were 96.8 and 99.4%, with an intra-day coefficient of variation of under 5 and 6%, respectively. Studies of analytical interference showed that the most commonly co-administered antidepressants and benzodiazepines did not interfere. The method was used for the determination of the plasma concentrations of a schizophrenic patient treated daily with an oral dose of 4.5 mg risperidone. The patient suffered severe extrapyramidal side-effects after adding risperidone to his previous medication of haloperidol and levomepromazine. The risperidone plasma concentration was well above the average (182 nmol/L), which suggests that a pharmacokinetic interaction occurred, presumably due to inhibition of the enzyme CYP2D6.

QTc interval lengthening is related to CYP2D6 hydroxylation capacity and plasma concentration of thioridazine in patients

Thioridazine cardiotoxicity has been associated with a prolonged heart-rate corrected QT (QTc) interval. However, no systematic studies have been performed on patients at therapeutic doses. The present study aimed to evaluate the influence of dose and plasma concentration of thioridazine and CYP2D6 enzyme status on the QTc interval in psychiatric patients. Sixty-five Spanish European psychiatric patients receiving thioridazine antipsychotic monotherapy were studied. The plasma levels of thioridazine and its metabolites were determined by high-performance liquid chromatography. All patients were phenotyped for CYP2D6 activity with debrisoquine during treatment. Thirty-five patients (54%) had a QTc interval over 420 ms. The lengthening of QTc interval was correlated with plasma concentration (p < 0.05) and daily dose (p < 0.05) of thioridazine. CYP2D6 enzyme hydroxylation capacity, evaluated by debrisoquine metabolic ratio (MR) (p < 0.05) and thioridazine/mesoridazine ratio (p < 0.05), was also correlated with QTc intervals. The present study shows the relationship between QTc interval lengthening among psychiatric patients treated at therapeutical doses with the dose and the plasma concentration of thioridazine. Since debrisoquine MR has been shown to be correlated with the QTc intervals, CYP2D6 enzyme hydroxylation capacity might be relevant in determining the risk for QTc interval lengthening. Patients with impaired CYP2D6 enzyme activity due to enzyme inhibition by thioridazine might be more prone to increased risk of sudden death due to torsade de pointes type cardiac dysrhythmia.

[Relationship between clozapine plasma levels and withdrawal symptoms]

Discontinuation of clozapine and an attempt to change his medication to sertindol has led to serious psychotic and somatic symptoms in an schizophrenic patient treated with clozapine for five years, however after readministration of clozapine these symptoms rapidly disappeared. To further analyse the case we have developed an HPLC method for the measurement of plasma levels of clozapine and its main metabolite N-desmethyl clozapine in order to monitor the plasma levels of clozapine and to correlate with the clinical symptoms. The present results confirmed that after discontinuation of clozapine no measurable amount of drug or its main metabolite were present in the plasma of the patient. The correlation between the plasma levels of clozapine and the changes in the clinical state of the patient confirmed that the patient's severe psychotic and somatic symptoms were the result of discontinuation of clozapine treatment. The clozapine plasma concentration of the patient reported here was low (100 ng/ml) compared to the generally accepted plasma levels for antipsychotic action of clozapine (350 ng/ml), however the somatic and psychotic clozapine withdrawal symptoms rapidly and completely disappeared.

Relationship between risperidone and 9-hydroxy-risperidone plasma concentrations and CYP2D6 enzyme activity in psychiatric patients

The implication of cytochrome P450 CYP2D6 enzyme activity in the metabolism of the antipsychotic drug risperidone has been reported in vitro and in studies of healthy volunteers. Around 7 % of Caucasians have inherited impaired capacity of this enzyme (poor metabolisers). These subjects might be prone to higher plasma concentrations of risperidone. The aim of the study was to determine the relationship between the debrisoquine metabolic ratio (MR), a marker of CYP2D6 enzyme activity, and risperidone plasma levels in psychiatric patients. A population of 40 Spanish and Hungarian schizophrenic patients was studied. The possible inhibition of CYP2D6 enzyme was also evaluated in a subgroup of patients co-medicated with inhibitors of CYP2D6. The risperidone/9-hydroxy-risperidone ratio correlated significantly with debrisoquine MR (p < 0.001). In patients co-medicated with strong inhibitors of CYP2D6, the plasma levels of risperidone (p < 0.05) and debrisoquine MR (p < 0.01) and risperidone/9-hydroxy-risperidone ratio were higher compared to patients with monotherapy. According to the present data, the evaluation of the risperidone/9-hydroxy-risperidone ratio may reflect the actual enzyme activity of CYP2D6. Therefore, the use of this ratio may help to assess potential pharmacokinetic interactions and to improve risperidone treatment.

[Spatial standardization of [15O]-butanol PET images using T1-weighted MRI data]

Population averaged brain activation studies require the spatial standardization of the individual perfusion PET images. This procedure is usually supported by T1-weighted MRI images. The authors developed a segmentation technique to improve the automatized transformation of the individual MRI images into Talairach space. It was for the first time in Hungary that population averages of standardized T1-weighted MRI and [15O]-butanol PET images of the brain were created after validation of the procedure using data from 23 healthy volunteers. The newly developed method offers a solution for the automatized processing of primary data from brain activation experiments prior to statistical analysis.

[Auditory event related potential and PET scan: a possibility for the comprehensive evaluation of cognition]

The authors studied the parallel use of event related potential (ERP) and brain activation PET in nine healthy volunteers. The presence of P300 wave in the EEG recording was accompanied by a parallel increase in the blood perfusion of the anterior cingulate gyrus. Furthermore, the functional connectivity between cortical and subcortical structures was also present during the task. This method combines the fine temporal-resolution of ERP and spatial-resolution of PET, which allows for the complex examination of fast cognitive processes. This approach may be useful in the investigation of psychiatric disorders.

[Use of positron emission tomography in psychiatry]

For the past years, substantial amount of experimental data has been published on the use of positron emission tomography in different psychiatric disorders. The different PET methods, which evaluate the whole-brain or regional metabolism, tissue perfusion or receptor density may help to identify the disorder specific changes in brain function and also better understand the underlying pathophysiology. In the clinical practice, PET plays an important role in the diagnosis and differential diagnosis of dementias and, presumably, in the near future the PET technique will be also extensively used in the clinical examination of other psychiatric disorders.

Effect of thioridazine dosage on the debrisoquine hydroxylation phenotype in psychiatric patients with different CYP2D6 genotypes

Sixteen hospitalized white European Spanish psychiatric patients treated with thioridazine alone were studied with respect to CYP2D6 genotype, debrisoquine metabolic ratio (MR), and the plasma levels of thioridazine and its metabolites mesoridazine and sulforidazine. After decreasing the dose of thioridazine the debrisoquine MR and thioridazine plasma levels were redetermined. At the initial determination (regular clinical doses, 20-300 mg/day), 14 of 16 patients (88%) were classified as poor metabolizers of debrisoquine (PMs). However, after complete withdrawal of thioridazine in 10 patients, all 10 became extensive metabolizers except two who were genotypically PMs (*4/*4). The inhibition of debrisoquine metabolism was genotype dependent. All patients with wt/wt genotype treated with a dose 150 mg/d were phenotypically PMs, all patients with wt/*4 genotype treated with a dose of 50 mg/d or greater were PMs. The debrisoquine MR from all dose changes correlated with the dose (p < 0.001) and plasma level (p < 0.001) of thioridazine. The CYP2D6 hydroxylation capacity was inhibited by thioridazine as determined by the debrisoquine MR. This inhibition was reversible by thioridazine withdrawal, and thus seems to be dose dependent and related to CYP2D6 genotype. One must consider the effects of thioridazine dosage on CYP2D6, because it may influence the metabolism of concomitant drugs or produce clinically important adverse effects such as cardiotoxicity. An awareness of this problem and cautious dosage adjustment of other drugs metabolized by the same enzyme are recommended during treatment with thioridazine.

Determination of clozapine and its N-desmethyl metabolite by high-performance liquid chromatography with ultraviolet detection

A rapid high-performance liquid chromatographic method has been developed for the simultaneous determination of the atypical antipsychotic drug clozapine and its principal metabolite, N-desmethyl clozapine in human plasma. After liquid-liquid extraction the compounds were separated in a reversed-phase column and measured by ultraviolet absorption at 230 nm. For both compounds inter-day variations were <3.8%, and, based on a plasma sample volume of 2 ml, the limits of quantification were 25 ng/ml. Analytical interference from coadministered psychoactive drugs and their metabolites was also studied, and no interference was found from the most commonly used antidepressants and antipsychotic drugs. The assay is sufficiently sensitive and easy to use for the analysis of plasma samples in human clinical trials and therapeutic drug monitoring.

Use of the mesoridazine/thioridazine ratio as a marker for CYP2D6 enzyme activity

Thioridazine is metabolized in humans by CYP2D6 to mesoridazine, which is an active metabolite. Two or more CYP2D6 substrates are seldom given simultaneously to elderly patients because potentially dangerous metabolic interactions may occur. It may be valuable to know the CYP2D6 metabolic capacity of such patients to avoid drug interactions, which depend on the metabolic phenotype. The goal of this study was to evaluate the use of the mesoridazine/thioridazine ratio for the estimation of CYP2D6 enzyme capacity. A sensitive and reliable method has been developed for the determination of thioridazine and its metabolites, mesoridazine and sulforidazine. Commonly used central nervous system (CNS) comedications do not interfere with the method. A group of 27 chronic patients with mental illness receiving monotherapy with thioridazine were studied. There were 23 men and 4 women between 37 and 80 years old (mean +/- SD: 61.2 +/- 10.2). The thioridazine/mesoridazine ratio correlated with the debrisoquine metabolic ratio (r = 0.74, p < 0.001). Therefore, the authors suggest that the measurement of thioridazine and its metabolite might be a useful tool to assess CYP2D6 activity during treatment.

Clozapine withdrawal symptoms after change to sertindole in a schizophrenic patient

A 30-year-old male patient with paranoid schizophrenia was on clozapine therapy for more than five years. Discontinuation of clozapine and an attempt to change his medication to sertindole has led to serious psychotic and somatic symptoms. After readministration of clozapine the psychotic symptoms rapidly disappeared. The patient was monitored by BPRS and PANSS positive and negative scale. Also clinical and labor parameters of the patient were monitored. The change of his medication from clozapine to sertindole was unsuccessful. This case report suggests that although atypical antipsychotics may be generally different from the classical neuroleptic drugs, there are also significant differences among the atypical antipsychotic drugs in their effects on the receptors of the central nervous system. Therefore the change of clozapine to another atypical antipsychotic medication in the clinical practice should be cross-tapered and the symptoms of withdrawal closely monitored.

Pharmacokinetic interaction of fluvoxamine and thioridazine in schizophrenic patients

This study investigated to what extent fluvoxamine affects the pharmacokinetics of thioridazine (THD) in schizophrenic patients under steady-state conditions. Concentrations of THD, mesoridazine, and sulforidazine were measured in plasma samples obtained from 10 male inpatients, aged 36 to 78 years, at three different time points: A, during habitual monotherapy with THD at 88 +/-54 mg/day; B, after addition of a low dosage of fluvoxamine (25 mg twice a day) for 1 week; and C, 2 weeks after fluvoxamine discontinuation. After the addition of fluvoxamine, THD concentrations relative to time point A significantly increased approximately threefold from 0.40 to 1.21 micromol/L (225%) (p < 0.002), mesoridazine concentrations increased from 0.65 to 2.0 micromol/L (219%) (p < 0.004), and sulforidazine levels increased from 0.21 to 0.56 micromol/L (258%) (p < 0.004). The THD-mesoridazine and THD-sulforidazine ratios remained unchanged during the study. Mean plasma THD, mesoridazine, and sulforidazine levels decreased at time point C, but despite fluvoxamine discontinuation for 2 weeks, three patients continued to exhibit elevated concentrations of THD and its metabolites. In conclusion, fluvoxamine markedly interferes with the metabolism of THD, probably at the CYP2C19 and/or CYP1A2 enzyme level. Therefore, clinicians should be aware of the potential for a clinical drug interaction between both compounds, and careful monitoring of THD levels is valuable to prevent the accumulation of the drug and resulting toxicity.

Antibiotic use in 3 European university hospitals

The use of antibiotic drugs was studied in university teaching hospitals in Tartu, Estonia, Huddinge, Sweden and Badajoz, Spain. Data on drug deliveries to hospital wards during 1992 are presented in defined daily doses (DDD) per 100 bed-days (DDD/100 bed-days). In addition, the time trends of antibiotic use in Tartu University Hospital from 1992 to 1995 are shown. The total amount of antibiotic drugs used for systemic treatment in 1992 was similar in the 3 hospitals, 41 DDD/100 bed-days in Tartu vs. 51 DDD/100 bed-days in Badajoz and 47 DDD/100 bed-days in Huddinge. The antibiotics used most frequently were tetracyclines and aminoglycosides in Tartu, broad-spectrum penicillins and cephalosporins in Badajoz and narrow-spectrum penicillins and cephalosporins in Huddinge. Injectable preparations accounted for one-half of the antibiotics used. Among the medical departments, the total use of antibiotics varied up to 3-fold (from 19 to 61 DDD/100 bed-days), less than among the surgical departments (18-94 DDD/100 bed-days). The frequency of antibiotic use was very similar in departments of similar profile in the 3 hospitals (i.e. in departments of neurology, urology, etc.). The use of antibiotic drugs in intensive care units was twice as high in Huddinge (243 DDD/100 bed-days) as in Badajoz (106 DDD/100 bed-days) and Tartu (135 DDD/100 bed-days) in 1992. In conclusion, the international differences in the use of antibiotics in hospital were not in the frequency of use, but in the predominant prescription preferences in the hospital.