[Psychiatric care for asylum seekers in Geneva: a multidisciplinary approach for individualized care]. / Soins psychiatriques pour les requérants d'asile à geneve. Une approche multidisciplinaire pour préserver la singularité des soins.

Asylum seekers constitute a vulnerable population insofar as they are submitted to numerous stress factors which facilitate the emergence of mental disorders, such as low socio-economic status, forced separation from loved ones and exposure to violence. Asylum seekers who consult at our community psychiatry facility usually have short-term residence permits, live in collective housing and do not speak the local language. The most frequent diagnoses are depressive disorder (64.7%) and post-traumatic stress disorder (34.5%). Due to their specific clinical and social situation and to the involvement of several professionals in these situations, a specialized psychiatric intervention coordinated with the rest of the network seems necessary.

Liver kidney microsomal type 1 antibodies reduce the CYP2D6 activity in patients with chronic hepatitis C virus infection.

Liver kidney microsomal type 1 (LKM-1) antibodies have been shown to decrease the CYP2D6 activity in vitro and are present in a minority of patients with chronic hepatitis C infection. We investigated whether LKM-1 antibodies might reduce the CYP2D6 activity in vivo. All patients enrolled in the Swiss Hepatitis C Cohort Study and tested for LKM-1 antibodies were assessed (n = 1723): 10 eligible patients were matched with patients without LKM-1 antibodies. Patients were genotyped for CYP2D6 variants to exclude individuals with a poor metabolizer genotype. CYP2D6 activity was measured by a specific substrate using the dextromethorphan/dextrorphan metabolic ratio to classify patients into four activity phenotypes. All patients had a CYP2D6 extensive metabolizer genotype. The observed phenotype was concordant with the CYP2D6 genotype in most LKM-negative patients, whereas only three LKM-1 positive patients had a concordant phenotype (six presented an intermediate and one a poor metabolizer phenotype). The median DEM/DOR ratio was sixfold higher in LKM-1 positive than in LKM-1 negative patients (0.096 vs. 0.016, P = 0.004), indicating that CYP2D6 metabolic function was significantly reduced in the presence of LKM-1 antibodies. In chronic hepatitis C patients with LKM-1 antibodies, the CYP2D6 metabolic activity was on average reduced by 80%. The impact of LKM-1 antibodies on CYP2D6-mediated drug metabolism pathways warrants further translational studies.

[Current topics in pharmacokinetics and pharmacogenetics of antidepressant drugs]. / Actualités pharmacocinétiques et pharmacogénétiques des antidépresseurs.

For antidepressants as well as for other drugs, personalized prescription has become a major challenge, provided the large interindividual variability encountered both at the pharmacokinetic and the efficacy and tolerance levels. Better identification of the numerous relevant factors and quantification of their effects are prerequisites to progress in that direction. On the basis of recent literature, genetic factors are first reviewed, including polymorphisms of genes coding for drug-metabolizing enzymes, transporters and pharmacodynamic target molecules. Current recommendations with respect to therapeutic drug monitoring of antidepressants and use of pharmacogenetic testing are then summarized.

Productive and physiological responses of lactating dairy cows supplemented with phytogenic feed ingredients.

This experiment compared milk production, milk composition, and physiological responses in lactating dairy cows supplemented with or without a mixture of condensed tannins, encapsulated cinnamaldehyde, curcumin, capsaicin, and piperine. Thirty-six lactating, multiparous, pregnant ¾ Holstein × » Gir cows were maintained in a single drylot pen with ad libitum access to water and a total-mixed ration and were milked twice daily (d -7 to 84). On d 0, cows were ranked by days in milk (86 ± 3 d), milk yield (27.8 ± 1.0 kg), body weight (BW; 584 ± 10 kg), and body condition score (BCS; 3.04 ± 0.06) and assigned to receive (SUPP; n = 18) or not (CON; n = 18) 30 g/cow daily (as-fed basis) of Actifor Pro (Delacon Biotechnik GmbH; Steyregg, Austria). From d 0 to 84, SUPP cows individually received (as-fed basis) 15 g of Actifor Pro mixed with 85 g of finely ground corn through self-locking headgates before each milking of the day. Each CON cow concurrently received 85 g (as-fed basis) of finely ground corn through self-locking headgates. Throughout the experimental period (d -7 to 84), cows from both treatments were administered 500 mg of sometribove zinc at 14-d intervals and were monitored daily for morbidity, including clinical mastitis. Individual milk production was recorded daily, whereas milk samples were collected weekly for analysis of milk composition. Cow BW, BCS, and blood samples were also collected weekly. Cows receiving SUPP gained more BCS (P = 0.05) and had greater (P = 0.04) milk yield during the experiment compared with CON cows (0.22 vs. 0.07 of BCS, SEM = 0.05; 29.5 vs. 27.9 kg/d, SEM = 0.5). Milk composition did not differ (P ≥ 0.15) between SUPP and CON cows; hence, SUPP cows also had greater (P ≤ 0.02) production of fat-corrected and energy-corrected milk. Incidence of clinical mastitis did not differ (P ≥ 0.49) between SUPP and CON cows. No treatment differences were also detected (P ≥ 0.21) for serum concentrations of glucose and serum urea N. Mean serum haptoglobin concentration during the experiment was greater (P = 0.05) in CON vs. SUPP cows. Cows receiving SUPP had less (P ≤ 0.04) serum cortisol concentrations on d 21 and 42, and greater (P ≤ 0.05) serum concentrations of insulin-like growth factor-I on d 7, 35, and 63 compared with CON cows (treatment × day interactions; P ≤ 0.02). Collectively, supplementing phytogenic feed ingredients improved nutritional status and milk production of lactating ¾ Holstein × » Gir cows.

Frequency of dysphoria and mixed states.

BACKGROUND: Mixed states are a complex entity in the field of mood disorders. Dysphoria has been advocated as an important clinical dimension of mixed states. The objective of this work is to study the frequency of dysphoria within a population of patients with DSM-IV major depressive and/or manic episodes and to determine if it may help establish diagnostic criteria for subthreshold cases of depressive or manic mixed states. SAMPLING AND METHODS: A total of 165 patients were assessed using the Mini International Neuropsychiatric Interview complemented by a section defining dysphoria as a constellation of 3 among 4 symptoms (inner tension, irritability, aggressive behavior and hostility). RESULTS: When classifying patients according to the number of symptoms of the opposite polarity, changes in the frequency of dysphoria revealed a clear contrast between the 2 opposite manic and depressive poles and the full mixed state (DSM-IV definition). The frequency of dysphoria was 17.5% in pure depression, 22.7% in pure mania and 73.3% in full mixed state. Two threshold effects were identified: (1) the frequency of dysphoria increased from 17.5 to 61.1% (p = 0.002) when the number of manic symptoms in DSM-IV depressed patients increased from 0 to 1, and (2) dysphoria increased from 14.3 to 69.2% (p = 0.057) when the number of depressive symptoms increased from 2 to 3 in DSM-IV manic patients. CONCLUSION: Dysphoria is strongly but not necessarily associated with mixed states. When used as a clinical marker for mixed states, dysphoria confirms the modern delimitations of sub-threshold mixed states by specifying the required number of symptoms of the opposite polarity (which could be lower for depressive mixed states than for manic mixed states). The study has limitations related to the inclusion of patients who are not drug-free, to the definition of dysphoria and to the sample size.

Developmental delay in communication among toddlers and its relationship to caregiving behavior among violence-exposed, posttraumatically stressed mothers.

OBJECTIVES: This study aimed to understand if maternal interpersonal violence-related posttraumatic stress disorder (IPV-PTSD) is associated with delayed language development among very young children ("toddlers"). METHODS: Data were collected from 61 mothers and toddlers (ages 12-42 months, mean age = 25.6 months SD = 8.70). Child expressive and receptive language development was assessed by the Ages and Stages Questionnaire (ASQ) communication subscale (ASQCS) that measures language acquisition. Observed maternal caregiving behavior was coded from videos of 10-min free-play interactions via the CARE-Index. Correlations, Mann-Whitney tests, and multiple linear regression were performed. RESULTS: There was no significant association between maternal IPV-PTSD severity and the ASQCS. Maternal IPV-PTSD severity was associated with continuous maternal behavior variables (i.e. sensitive and controlling behavior on the CARE-Index) across the entire sample and regardless of child gender. Maternal sensitivity was positively and significantly associated with the ASQCS. Controlling behavior was negatively and significantly associated with the ASQCS. CONCLUSIONS: Results are consistent with the literature that while maternal IPV-PTSD severity is not associated with child language delays, the quality of maternal interactive behavior is associated both with child language development and with maternal IPV-PTSD severity. Further study is needed to understand if the level of child language development contributes to intergenerational risk or resilience for relational violence and/or victimization.

A stepwise drug treatment algorithm to obtain complete remission in depression: a Geneva study.

QUESTIONS UNDER STUDY/PRINCIPLES: We describe the proportion of severely depressed outpatients reaching complete remission at the different stages of a drug treatment algorithm. We compare several treatment options for SSRI (selective serotonin reuptake inhibitor) non-responders and test the feasibility of the algorithm in clinical conditions. METHODS: Patients with severe depressive disorders (ICD-10; MADRS > or = 25) admitted to an academic outpatient clinic were enrolled in this algorithm-guided sequential treatment protocol (starting with an SSRI and ending with a tricyclic, lithium, triodothyronine combination). The general principle of the algorithm was to boost the drug therapy in the event of non-response. RESULTS: 135 patients entered the study and 131 were eligible for analysis. From this group, 86 patients dropped out (65.6%), 40 reached complete remission (30.5%) and 5 patients did not reach remission at all (3.8%). In the 117 patients to whom a last observation carried forward approach was applied, the median improvement of the MADRS score was 48.0% (range -20.7%-100%), with 48.7% of patients considered responders, 23.1% partial responders and 28.2% non-responders. Median retention time was 8 weeks (range 2-34). CONCLUSIONS: This algorithm-guided antidepressant treatment was acceptable for clinicians and resulted in an elevated final response rate among study completers. However, the dropout rate was high, mainly due to treatment interruption or non-observance.

[Validation of the QFS measuring the frequency and satisfaction in social behaviours in psychiatric adult population]. / Validation du Questionnaire de fonctionnement social (QFS), un autoquestionnaire mesurant la fréquence et la satisfaction des comportements sociaux d'une population adulte psychiatrique.

INTRODUCTION: Although everyone working in routine mental health services recognizes the scientific and ethical importance to ensure that treatments being provided are of highest quality, there is a clear lack of consensus regarding what outcome domains to include, what measure of assessment to use and, moreover, who to question when assessing. LITERATURE FINDINGS: Since the fifties, social functioning is considered as an important dimension to take into account for treatment planning and outcome measuring. But for many years, symptoms scales have been considered as sufficient outcome measures and social functioning improvement expected on the basis of symptoms alleviation. As symptoms and social adjustment sometimes appear relatively independent, no accurate conclusion concerning the patient's social functioning can so be driven on the basis of his clinical symptoms. More attention has then been directed toward the development of instruments specifically intended to measure the extent and nature of social functioning impairments observed in most psychiatric syndromes. Many of these instruments are designed to be completed by caregivers or remain time consuming and difficult to use routinely. Presently, in clinical practice, there is a need to rely on simple and brief instruments considering patients'perspective about their social adjustment as a function of time. AIM OF THE STUDY: The aim of this study is to present a new instrument, the QFS, initially developed in order to assess social functioning in patients involved in group psychotherapy programs conducted in a specialist mental health setting, as well as its psychometric characteristics. METHODOLOGY: It was designed to be completed in less than 10 minutes and the questions are phrased in a simple and redundant way, in order to limit problems inherent to illiteracy or language comprehension. The QFS is a 16 items self-report instrument that assesses both the frequency of (8 items) and the satisfaction with (8 items) various social behaviours adopted during the 2 weeks period preceding the assessment. It yields three separate indexes of social functioning, defined a priori and labelled "frequency", "satisfaction" and "global". The higher the scores, the better the social functioning. The QFS was administered to 457 subjects, aged between 18 and 65, including 176 outpatients (99 with anxious or depressive disorders, 25 with personality disorders and 52 with psychotic disorders) and 281 healthy control subjects. RESULTS: No significant difference was found between patients and controls according to age or gender distribution. Acceptance rate was high (>95%). Moreover, the QFS was generally acceptable to the clinicians who used it. Internal consistency calculated for each index ranged from 0.65 to 0.83 (Cronbach alpha). Test-retest reliability, calculated within a 15 days time interval on a sample of 49 healthy controls, ranged from 0.69 to 0.71 (intraclass correlation coefficient). Discriminant validity was calculated on healthy controls and patients divided into sub-groups according to their diagnosis. It showed to be excellent, with significantly higher scores in control subjects than in psychiatric patients and significant differences across diagnostic categories (Kruskal-Wallis ANOVA with post-hoc tests, all p<0.05). The convergent validity of the QFS with other measures of social functioning was calculated, using the Social Adaptation Self-Evaluation Scale (SASS) and the Social Adjustment Scale Self-Report (SAS-SR). With the SASS, the convergent validity was higher among patients (Spearman rS 0.71 to 0.92, p<0.01) than controls (rS from 0.49 to 0.66, p<0.001). In healthy controls, correlation with the SAS-SR was moderate but statistically significant (rS from - 0.21 to - 0.44, p<0.05). When comparing QFS scores with self-rated symptoms severity, lower levels of social functioning were significantly associated with more severe symptoms according to the Brief Symptom Inventory (BSI: rS from - 0.38 to - 0.65, p<0.001). The QFS indexes demonstrated sensitivity to change (Wilcoxon: all p<0.05) on a sample of 27 out-patients suffering from anxious-depressive disorders questioned before and after 4 months of cognitive behavioural group therapy running on a weekly basis during 16 sessions of 2 hours each.The factorial validity of the QFS was measured through 3 separate factor analysis conducted using the data of 457 subjects. The first analysis considered only Frequency items; 7 out of 8 items had loadings above 0.5 on Factor 1 accounting for 30.7% (unrotaded) of the variance. The second analysis considered only Satisfaction items; all items had loadings above 0.6 on Factor 1 explaining 43.4% (unrotaded) of the variance. And finally, in the third factor analysis, all QFS items were included; 15 out of 16 items had loadings above 0.4 on Factor 1 accounting for 30% (unrotated) of the variance. Concerning the factorial validity of the instrument, these results suggest that all QFS items belong to the same underlying dimension. DISCUSSION: Finally, provisional norms for the QFS are provided for healthy controls, in order to characterise individual patients or patient subgroups. In conclusion, the need for assessment in clinical routine, in order to estimate different aspects of patients conditions as well as the quality of the treatment provided, has contributed to the development of a large variety of instruments measuring several domains. Concerning the level of social functioning, many instruments fail to meet chief criterion of feasibility, remaining often too complex or time onsuming. Moreover, only few of them are available in French. CONCLUSION: The QFS presented here is a brief, simple and easy to administer self-rating scale that displays satisfactory psychometric properties. It seems to be a valuable instrument for the monitoring of social functioning in psychiatric patients which, from a therapeutic point of view, may have a clear impact as it sets up expectation of change and allows both to reality test patients and therapists beliefs about the presence of progress or not and to identify if therapy is working on this specific outcome domain. Though, to date, the administration of the QFS to other populations and treatment modalities requires further investigation.

A novel water-soluble cyclosporine A prodrug: ocular tolerance and in vivo kinetics.

The purpose of this study is to demonstrate that a novel water-soluble prodrug of cyclosporine A (CsA) intended for topical ocular administration, does not induce eye irritation in a rabbit model and is able to generate therapeutic concentrations of CsA in the precorneal area immediately after administration. The eye irritancy of the prodrug and CsA control solution was assessed by the Draize test and by confocal laser ophthalmoscopy (CLSO). Residence time and tear concentrations of prodrug and CsA in the rabbit eye were assessed by HPLC. The Draize test showed an excellent tolerance for the prodrug solution while the reference CsA oil solution induced lachrymation and irritation. The CLSO-measured corneal lesions, subsequent to treatment with the prodrug and reference solutions, were 3% and 9%, respectively. The prodrug transformed rapidly, leading to relatively stable CsA concentrations in tears with a maximal concentration of 94 microg ml(-1) over the observation period. This study demonstrated that the prodrug solution was well tolerated and that clinically significant CsA tear concentrations were achieved. UNIL088 is a promising molecule in the treatment of immune-related disorders of the eye.

Identifying weak signals in the presence of noise: a new method of locating potential ligand contact residues in immunoglobulin-related molecules.

We develop and apply a new method for estimating the locations of hypervariable residues in immunoglobulin-related molecules. The method differs from the standard introduced by Wu and Kabat in two essential ways: (1) we take explicit account of the type of substitution at a given position, rather than just the total number of substitutions, and (2) we use an explicit statistical decision criterion for classifying a site into either the complementarity determining or framework category. Simulations indicate that the method is reliable with relatively little data, approximately 5% of the sites being misclassified when 10 sequences are aligned. The method is applied to immunoglobulin light chains and to class 1 and class 2 products of the major histocompatibility complex.

Clinical pharmacokinetics of clomipramine.

Clomipramine is a tricyclic antidepressant medication widely used in Western Europe. Its pharmacokinetics have been studied essentially in healthy volunteers. By combining published information obtained during observational studies, it has been possible to derive a fairly precise picture of the behaviour of both parent compound and main metabolite (demethyl-clomipramine) in humans. Clomipramine can be compared with amitriptyline or imipramine so far as its physicochemical properties are concerned. As a consequence, its pharmacokinetic profile is also similar to that observed for these 2 drugs. Clomipramine is well absorbed from the gastrointestinal tract, but undergoes an important first-pass metabolism to demethyl-clomipramine which is pharmacologically active and participates in both therapeutic and unwanted effects. Protein binding is high, and the apparent volume of distribution is very large (i.e. greater than 1000L). After reaching the systemic circulation, clomipramine is further biotransformed into demethyl-clomipramine, and both active principles are hydroxylated to metabolites which are further conjugated before being excreted in urine. Hydroxylation of parent drug and metabolite is under polymorphic genetic control by the same cytochrome P450 as debrisoquine and sparteine. The apparent elimination half-life of clomipramine is about 24h and that of demethyl-clomipramine, 96h. Accordingly, the time to reach steady-state for both active moieties is in general around 3 weeks. Various pathological or environmental factors influence the behaviour of clomipramine and demethyl-clomipramine. Patients genetically deficient in hydroxylation accumulate demethyl-clomipramine at high concentrations that can produce serious side effects and/or nonresponse. The same is true for the coadministration of neuroleptics, in particular phenothiazines. Smoking induces demethylation, whereas long term alcohol intake appears to reduce this metabolic pathway. Finally, age usually diminishes both demethylation and hydroxylation, leading to a lower daily dose of clomipramine in most elderly patients. Studies relating blood concentrations of clomipramine and demethyl-clomipramine are conflicting. However, analysis of the available information indicates that blood concentrations lower than 150 micrograms/L are usually associated with nonresponse, whereas those above 450 micrograms/L seldom lead to an improvement in the efficacy of therapy. As a consequence clomipramine, like the other tricyclics, is an antidepressant with a fairly narrow therapeutic range. This property, combined with a high interindividual variability, makes this class of drugs ideal candidates for blood concentration monitoring.

Clomipramine metabolism. Model-based analysis of variability factors from drug monitoring data.

A steady-state model is here developed as a framework for the analysis of blood concentrations of clomipramine, obtained during routine drug monitoring. A model is proposed to account for its major metabolic pathways, hydroxylation and demethylation, including first-pass effect. Impaired hydroxylation capacity is shown to lead to a dramatic increase in the concentration of demethyl-clomipramine, with a concomitant moderate increase in that of the parent drug. Deficient demethylation capacity is associated with a reduced ratio of demethyl metabolite to parent drug. A nomogram is provided to allow easy determination of hydroxylation and demethylation capacities from routinely measured blood concentrations. Data from 150 patients are analysed in order to identify interindividual variability factors. Average pseudo-clearances, calculated from trough blood concentrations at steady-state, are 17 L/h for hydroxylation, 23 L/h for demethylation and 40 L/h for elimination of hydroxylated metabolites. Maximum to minimum ratios are 8, 27 and 11, respectively. The metabolising capacity through either process significantly decreases with increasing age, clearance estimates being 40 to 50% lower for patients 75 years or older than for those 40 years or younger. Tobacco smoking and chronic alcohol consumption induce and reduce the demethylation clearance, respectively. Inhibition of hydroxylation in the presence of phenothiazine comedication is also shown. Finally, small but significant differences according to sex are observed. Potential implications of the proposed model-based approach include adaptation of the dosage regimen to individual characteristics at the very beginning of antidepressant therapy, and early detection of patients with impaired metabolising capacities.

Multivariate analysis of dietary patterns in 939 Swiss adults: sociodemographic parameters and alcohol consumption profiles.

A dietary survey of 939 Swiss adults, randomly selected from the population of Geneva and its surrounding communities, was performed according to the history method. A factor analysis, using average weekly intakes for 33 food variables, reveals three principal components of the diet: satiating capacity, healthfulness and culinary complexity. These characteristics, together with the energy content of the diet, were analysed for differences according to sex, age, relative weight index, birthplace, marital status and occupation. All of these sociodemographic variables influence some dimension of dietary habits. Alcohol consumption is positively associated with satiating, protein rich diets, but energy intake from foods does not significantly differ between various groups of abstainers and drinkers. Although the energy contribution of alcoholic beverages is globally additive, we suggest that cultural and societal norms may modulate the relationship of alcohol and diet.

Therapeutic drug monitoring databases for postmarketing surveillance of drug-drug interactions.

Drug-drug interactions can be associated with patient morbidity due to either increased toxicity or a potentially ineffective concentration. Because interactions cannot always be anticipated during drug development and actual patients receiving a drug for therapeutic use often differ from those included in clinical trials, postmarketing surveillance is essential. Therapeutic drug monitoring (TDM) databases offer a unique opportunity in this respect. Prerequisites for TDM databases to provide valid information in a pharmacoepidemiological perspective include the following: precise description of exposure to the potentially interacting drugs; measurement of parent compound and active metabolites through accurate and precise analytical techniques; documentation of relevant patient characteristics that may act as confounding factors (e.g. gender, age, smoking habits); repeated assessments over time if possible; and sound pharmacokinetic framework for data selection, analysis and interpretation. The contribution of TDM to the documentation of drug-drug interactions takes advantage of different possible study designs, discussed on the basis of recently published studies. The single case report plays an important role as an alert signal. It is illustrated for a patient on long-term treatment, who displayed an unexpectedly high clozapine concentration after the introduction of ciprofloxacin comedication. The prospective on and off comedication panel study shows advantages in terms of carefully selected inclusion criteria and control of treatment modalities. A study of the thioridazine-fluvoxamine interaction is presented, with patients followed on thioridazine monotherapy, after introduction of fluvoxamine and after its discontinuation. The main advantage of the retrospective large-scale TDM database screen is representativeness of patients actually treated, whereas drawbacks are related to quality of data and suitability for valid interpretation. Such an approach is illustrated by a review of data collected over 10 years of routine TDM that allowed documenting induction of nortriptyline metabolism by carbamazepine and inhibition by several phenothiazines. Finally, population pharmacokinetics is well suited to observational data collected for TDM purpose, provided quality is ascertained. Focus is placed on interindividual variability and relationship between pharmacokinetic parameters and patient characteristics, including comedication. The population approach is discussed with respect to a study that documented a 32% increase of haloperidol clearance associated with anticonvulsant comedication, in addition to effects of age and bodyweight. Among factors to consider for improved effectiveness in the use of TDM databases for postmarketing surveillance of drug-drug interactions, integration of efficacy and safety data in future studies and communication of expert recommendations to prescribing physicians are essential.

Optimized release of dexamethasone and gentamicin from a soluble ocular insert for the treatment of external ophthalmic infections.

In the case of external ophthalmic infections, repeated instillations of antibiotics are required to reach therapeutic level, above the minimal inhibitory concentration (MIC). An additional administration of a corticosteroid is often needed, in order to limit the precorneal damages caused by the infection. However, repeated administration of a corticosteroid can increase intraocular pressure and thus lead to glaucoma. To overcome the disadvantages of separated and repeated instillations of two products and to avoid the side effects of dexamethasone, a soluble insert containing gentamicin sulfate and dexamethasone phosphate was developed. The new system ensures the concomitant release of the two drugs during the first 10 h of treatment, followed by an adequate concentration of gentamicin sulfate, above the MIC of 4.0 microgram ml-1, during 50 h, due to a combination of gentamicin sulfate with cellulose acetate phthalate, which reduces the solubility of gentamicin.

Modelling during drug development.

With the advancement of both biological and computer sciences, new drug development faces the challenge to integrate a huge amount of knowledge accumulated from the very early quantitative structure-activity relationship investigations of the candidate molecule to the large scale clinical trials in patients. Whereas pharmacokinetics and pharmacodynamics are fields in which modelling has long demonstrated its value, its potential in many other areas of drug development has recently been the object of intensive scientific activity. The present review places emphasis on these newer applications; it includes the opinion of many experts in often highly specialised areas such as in vitro to in vivo extrapolation, toxicokinetics, non-continuous response models, population approaches and computer assisted simulation of clinical trials. It is most probable that in the near future many of these areas of research will be the objects of intensive and interesting developments. This will undoubtedly lead to improve developmental strategies for new drugs as well as more individualised pharmacological strategies for patients.

Basis for dosing time-dependent changes in the ocular and systemic absorption of topically applied timolol.

The objective of the present study was to determine the basis for dosing time-dependent changes in the ocular and systemic absorption of topically applied timolol in pigmented rabbits. The gamma scintigraphic technique was used to monitor the changes in precorneal solution retention following instillation. Changes in timolol concentration in the plasma over 120 min and in various anterior segment eye tissues at 30 min following the topical instillation of 25 microliters of 0.65% timolol maleate solutions at various dosing times were monitored using reversed phase HPLC. Corneal and conjunctival permeability at various dosing times was evaluated in the modified Ussing chamber. The results indicated that precorneal solution drainage was slowest at noon. Suppressing tear production by anesthesia led to an increase in ocular timolol absorption at 6 a.m. but not at other dosing times, in spite of the lowest corneal permeability then. There was no statistically significant dosing time influence on systemic timolol absorption following nasal or conjunctival dosing. In conclusion, possible diurnal changes in precorneal solution clearance may be the main factor underlying the diurnal changes in ocular as well as systemic timolol absorption in rabbits. In addition, diurnal changes in corneal permeability may also contribute to diurnal changes in ocular timolol absorption.

[The contribution of alcohol to nutrition: addition or substitution according to cultural origins]. / Contribution de l'alcool à l'alimentation: addition ou substitution selon l'origine culturelle.

The relation of alcohol intake to diet is analyzed through multiple linear regression for a sample of 475 males living in Geneva. Control variables are age, relative weight index, marital status and employment status. Whereas alcohol is associated with higher dietary intake for people of mediterranean origin, it tends to replace food calories for natives of german speaking areas.

Stereoselective disposition of flupentixol: influence on steady-state plasma concentrations in schizophrenic patients.

Steady-state plasma concentrations of cis(Z)-flupentixol (active principle) and trans(E)-flupentixol (inactive) were measured in 41 patients at least on one occasion. Results indicate that concentrations of the trans-isomer are significatively higher. This demonstrates that the two isomers are not handled in the same way by the organism. This may be relevant if plasma level monitoring is performed using non-specific analytical methods.

Drug metabolism as a confounding factor in PK/PD population approaches.

Pharmacokinetic/pharmacodynamic population approaches aim at establishing relationships between dose, drug concentration of active principles and clinical response, accounting for factors responsible for inter-individual variability. Additional difficulties in the presence of metabolites include the need to decide a priori which metabolites should be monitored according to their respective role in efficacy and/or toxicity, the need to select appropriate selective analytical methods, and the requirement for more complex pharmacokinetic and/or pharmacodynamic models. These points are discussed more extensively for psychotropic drugs, and in particular for the active metabolites of phenothiazines, for reduced haloperidol, for the desmethylated and hydroxylated metabolites of tricyclic antidepressants, and for the desmethyl metabolites of the serotonin-specific reuptake inhibitors fluoxetine and citalopram.