[First French-speaking days of users of decision support system in clinical pharmacy: Feedback and perspectives]

Clinical decision support systems (CDSS) are tools that have been used for several years by clinical pharmacy teams to support pharmaceutical analysis, with a perspective of contributing to the quality of care in collaboration with the other health care team members. These tools require both technical, logistical and human resources. The growing use of these systems in different establishments in France and in Europe gave birth to the idea of meeting to share our experiences. The days organized in Lille in September 2021 aimed at proposing a time of exchange and reflection on the use of these CDSS in clinical pharmacy. A first session was devoted to feedback from each establishment. These tools are essentially used to optimize pharmaceutical analysis and to secure patient medication management. This session outlined the clear advantages and common limitations of these CDSS. Two research projects were also presented to put the use of these tools into perspective. The second session of these days, in the form of workshops, addressed 4 themes that surround the implementation of CDSS: their usability, the legal aspect, the creation of rules and their possible valorization. Common problems were raised, the resolution of which requires close collaboration. This is a first step proposing a beginning of harmonization and sharing that should be deepened in order not to lose the dynamics created between the different centers. This event ended with the proposal to set up two working groups around these systems: the creation and structuring of rules for the detection of risk situations and the common valorization of the work.

[Standardized computer recording of clinical pharmacy procedures in health care institution: Feedback and evaluation of potential economic value]

Clinical pharmacy procedures are clearly defined by the French society of clinical pharmacy. However, clinical pharmacists do not have efficient tools for their traceability. This need has increased following the publication of the instruction on the day hospital management of patients. Indeed, the action of the clinical pharmacist is included in it. In order to improve our traceability of clinical pharmacy acts and to take advantage of the implementation of the instruction, we worked with the medical information department to integrate our activity into their business software and to model the pathways valued by the intervention of the clinical pharmacist in outpatient care and in day hospital.

Impression Management on Instagram and Unethical Behavior: The Role of Gender and Social Media Fatigue

Impression management (IM) concerns can lead to significant psychological consequences, potentially engendering unethical behavior. Therefore, adopting the stressor-strain-outcome framework, this study explores the effects of IM concerns on unethical behavior through wellbeing, and whether IM on social media (i.e., Instagram) triggers fatigue and results in unethical behavior at work. The findings of two empirical studies (n = 480 and n = 299) in different settings (Kuwait and the UK) suggest that women experience higher effects from IM concerns compared with men in Kuwait, while no gender differences are found in the UK. The results also confirm that impression management on social media platforms triggers fatigue, in turn increasing unethical behavior at work. This study contributes to the IM literature by capturing the effect of Instagram activities on workplace behavior.

The clinical pharmacist's role in enhancing the relevance of a clinical decision support system

BACKGROUND

Clinical decision support systems (CDSSs) can improve the quality of patient care by helping physicians to review their prescriptions and thus to optimize drug treatments. Nevertheless, the "alert fatigue" brought on by a large number of irrelevant alerts can decrease a CDSS's effectiveness and thus clinical value. Involving a clinical pharmacist in the development and management of a CDSS can reduce the number of irrelevant alerts presented to physicians. Clinical pharmacists screen alerts and suggest PIs for physicians, corresponding to any proposed therapeutic change about health products, only for relevant alerts could improve the relevance and the acceptance of the information given to physicians about the risks faced by their patients.

OBJECTIVE

To assess the value of involving clinical pharmacists in the development and maintenance of decision support rules for generating alerts and pharmaceutical interventions (PIs) and to describe the level of acceptance of these PIs by the physicians.

METHOD

In a retrospective, single-centre study, we evaluated the number of PIs accepted from alerts generated by the CDSS when a clinical pharmacist had developed and managed this tool. During the first 7 months of development of the CDSS, a clinical pharmacist analyzed alerts triggered by the CDSS according to its technical validity and pharmaceutical relevance. Lastly, for alerts that led to a PI, the level of acceptance by physicians was documented.

RESULTS

During the study, 1430 alerts were analysed: 186 (13%) were considered to be technically invalid - mainly due to the characteristics of the interface. Of the 1244 (87.0%) technically valid alerts, 353 (24.6%) were pharmaceutically relevant and led to a PI. The three main causes of pharmaceutical irrelevance were a lack of specificity in the CDSS (70.8%), lack of relevance with regard to the ward's habits (15.6%), and the pharmacist's decision to recommend monitoring for the patient rather than sending a PI immediately (10.8%). 64.6% of the submitted PIs were accepted by the physicians.

CONCLUSION

The standardized analysis of alerts by a clinical pharmacist appears to be a good way of improving the development of CDSS by limiting the generation of irrelevant alerts and the latter's transmission to physicians. The involvement of a clinical pharmacist in the development and implementation of a CDSS appears to be novel and may help to optimize drug treatment.

[Evaluation of the training of clinical pharmacy residents in prescription analysis using an ergonomic approach]

OBJECTIVES

To perform an ergonomic intervention using the methodology of the analysis of the activity of the training process of clinical pharmacy residents in the analysis of prescriptions.

METHODS

The evaluation was carried out over two semesters: from May to October 2016 (first study) and from November 2016 to April 2017 (second study). The interviews and observations were conducted by an ergonomist who is an expert in this type of evaluation. The first study was based on observations of the training process and interviews at different time. The second study allowed to support pharmacists and evaluate the changes following the recommendations of the previous study.

RESULTS

A total of 6 and 9 residents participated in the first and second study, respectively. During the first study, 6 difficulties were raised which allowed implementation decisions. Feedback from residents on the training process was generally positive for the first part of the training but negative for the last part. The average number of fears expressed by the residents was higher at the beginning (2.9 fears) than at the end (1 fear).

CONCLUSIONS

The training process has been adapted to the expectations and feelings of the residents. Follow-up at the beginning and throughout the internship was essential. The next stage of this work will be to evaluate the contribution of the dashboards for monitoring clinical pharmacy skills in the new degree for hospital pharmacy.

Traces pilot pharmacokinetic study dataset

The dataset displays the pharmacokinetics data obtained from the TRACES pilot study. The nine patients included were undergoing haemorrhagic caesarean section (blood loss > 800 mL) and receiving a single i.v dose of tranexamic acid (0.5, 1 or 2 g over 1 min).

The dataset gathers the tranexamic acid blood and urinary concentrations. With these first elements, a pharmacokinetic compartment model was built as described in Gilliot et al. and the individual pharmacokinetic parameters were estimated. In parallel, the patients anthropometric, biological, and clinical characteristics were collected. The correlation between the patient data and the estimated individual pharmacokinetic parameters were tested.

The correlation tests revealed that the dose, the height, the body weight, and the ideal bodyweight had and impact on the volume of distribution of tranexamic acid. According to these results, these latter covariates were explored using a multi-regression analysis in Gilliot et al.

[Evaluation of knowledge and perceptions of pharmacists and residents pharmacists about bibliometric indicators applied to the scientific literature in pharmacy]

OBJECTIVES

Evaluate the level of knowledge and perceptions of French and Quebec hospital's pharmacists/residents about bibliometrics indicators applied in pharmacy. Identify the determinants associated with this knowledge.

METHODS

This is a descriptive cross-sectional study. An anonymous questionnaire of 17 questions answers was developed. The questionnaire was published on the SurveyMonkey site (www.SurveyMonkey.com, SurveyMonkey, Portland, OR, USA) and released from March 19 to April 9, 2018. We calculated and compared the proportion of respondents in Quebec and France by using a Chi² test. A value less than 0.05 is considered statistically significant.

RESULTS

A total of 899 pharmacists (646 in Quebec and 253 in France) and 147 residents (70 in Quebec and 77 in France) were contacted by email. The survey was completed by 401 respondents, e.g., 301 in Quebec (participation rate: 42%) and 100 in France (30%). Overall 26% (106/401) of respondents (67/301 in Quebec vs. 39/100 in France) reported having knowledge or good knowledge of those indicators. These data are corroborated by many other results.

CONCLUSIONS

Small proportions are aware of those indicators. A good knowledge is associated with being a French pharmacist, working in a teaching hospital or university, having a professional experience of 10 years or more, be involved in a research project, having a scientific watch or having an online profile on database. It appears necessary to inform pharmacists and residents on notoriety indicators.

A new pharmacokinetic model for 90Y-ibritumomab tiuxetan based on 3-dimensional dosimetry

Monoclonal antibodies (mAbs) are key components in several therapies for cancer and inflammatory diseases but current knowledge of their clinical pharmacokinetics and distribution in human tissues remains incomplete. Consequently, optimal dosing and scheduling in clinics are affected. With sequential radiolabeled mAb-based imaging, radiation dosing in tissues/organs can be calculated to provide a better assessment of mAb concentrations in tissues. This is the first pharmacokinetic model of ⁹⁰Y-Ibritumomab tiuxetan (⁹⁰Y-IT) in humans to be described, based on three-dimensional (3D) dosimetry using single-photon emission computed-tomography coupled with computed-tomography. 19 patients with follicular lymphoma were treated initially with ⁹⁰Y-IT in the FIZZ trial. Based on a compartmental approach individualising the vascular compartment within studied organs, this study proposes a reliable pharmacokinetic (PK) five-compartment model replacing the currently used two-compartment model and constitutes a new direction for further research. This model provides exchange constants between the different tissues, Area Under the Curve of ¹¹¹In-IT in blood (AUC) and Mean Residence Time (MRT) that have not been reported so far for IT. Finally, the elimination process appears to occur in a compartment other than the liver or the spleen and suggests the metabolism of mAbs may take place mainly on the vascular compartment level.

Prospective assessment of patients' knowledge and informational needs and of surgeon-to-patient information transfer before and after knee or hip arthroplasty

BACKGROUND

Patients are playing an increasingly large role in their own management and must therefore receive clear, complete, and comprehensible information. In the field of hip and knee arthroplasty, little is known about the level of patient knowledge and effectiveness of surgeon-to-patient information transfer. We therefore designed a prospective observational study with the objective of assessing four factors: patient knowledge during management, quality of information transfer, informational needs, and factors associated with the level of knowledge.

HYPOTHESIS

The level of patient knowledge changes during the management process.

PATIENTS AND METHODS

A prospective single-centre study was conducted between January 2014 and March 2015 during the outpatient visits and inpatient stays of 63 patients who underwent arthroplasty of the hip (n=36) or knee (n=27). A single observer attended all patient visits and recorded the information provided by the surgeon. Each patient completed a self-questionnaire after the outpatient visit (T1), at admission (T2), and at discharge after surgery (T3). Semi-quantitative scores were used to assess knowledge and informational needs. The effectiveness of information transfer was evaluated by comparing the information provided by the surgeon to the replies made by the patients.

RESULTS

The mean overall knowledge score (on a 0-42 scale) increased from 17.22±6.33 at T1 to 19.44±6.89 at T3 (P=0.0028). In contrast, knowledge about complications was better at T1 than at T3 (2.67±1.98 vs. 2.19±1.91; P<0.05). Agreement between information given by the surgeon and replies made by patients varied across items from 23% to 100%. The mean informational needs score (on a scale from 0 to 21) ranged from 3.67 to 4.83 and was higher at T3 than at T2 (4.83±3.77 vs. 3.67±4.86; P=0.03). The proportion of patients who wanted written information was higher at T3. Most patients sought information before the outpatient visit. At each step of the management process, the main areas about which the patients wanted information were the surgical procedure, the rehabilitation programme, and the prosthesis. Several socio-demographic or management-related factors influenced the level of knowledge. Thus, older age and lower educational attainment were associated with lower knowledge scores, whereas previous lower-limb orthopaedic surgery and amount of information provided by the surgeon were associated with higher knowledge scores. Knowledge scores were not associated with being employed vs. retired, gender, replacement of a hip vs. a knee, the surgeon, or being accompanied by another person.

DISCUSSION

Our study is original in that we assessed changes in patient knowledge during the management process for hip or knee arthroplasty. The level of patient knowledge was fairly low and varied considerably across individuals and time points in the management process. These data highlight the importance of providing patients with information throughout their management and particularly at discharge, when the desire for information seems greatest.

LEVEL OF EVIDENCE

IV, prospective observational study with no control group.

[Comparative profile of the use of filter needles in Quebec and France in healthcare facility]

OBJECTIVES

The manipulation of drugs from glass ampules can generate particles when the ampule is broken. Several authors recommend the use of filter needle to withdraw the drug content. The main objective is to establish an inventory of the use of filter needles and the perception of pharmacists in Quebec and in France.

METHODS

This is a cross-sectional descriptive study. A questionnaire was sent to all health facilities in Quebec (n=30) and a selection of hospitals in France (n=100). Respondents were asked to answer a questionnaire that included policies and procedures on the use of these medical devices and the conditions of their use at the pharmacy and in healthcare services.

RESULTS

In total, 27 respondents from Quebec (response rate: 90%) and 41 respondents from France (response rate: 41%) participated in our survey. In Quebec, all exploitable questionnaires except one (42/43) used five micron filter needles at the pharmacy against 28% of utilisation in healthcare services. In France, this practice is nearly ignored.

CONCLUSIONS

Action should be taken to decide on the use of filter needles including studies to confirm the consequences of the presence of these particles on an animal model, discussions with regulatory authorities to clarify the situation, incentives for manufacturers to use vials.

Factors Generating Glucose Degradation Products In Sterile Glucose Solutions For Infusion: Statistical Relevance Determination Of Their Impacts

Sterilising glucose solutions by heat promotes the generation of a large number of glucose degradation products (GDPs). It has been shown that high levels of GDPs may result in Advanced Glycation End products that have an impact on cellular homeostasis and health in general. If data is available for peritoneal dialysis solutions, little has been published for glucose infusion fluids. It is essential to identify the parameters causing the formation of GDPs and so limit the risk of exposing patients to them. After quantifying both 5-hydroxymethyl-2-furfural, considered as an important indicator of degradation, and 2-furaldehyde, an ultimate GDP of one degradation pathway, in marketed solutions, the aim of this work is to build a model integrating all the parameters involved in the formation rates of these two GDPs: supplier, glucose amount, container material, oxygen permeability coefficient and time-lapse since manufacture. Our results show a good logarithmic relationship between GDP formation rates and time-lapse since manufacture for both GDPs. The amount of GDPs in the glucose solutions for infusion depends on the initial glucose amount, the polymer of the container, the time elapsed since manufacturing and the supplier.

Analysis of plasticizers in PVC medical devices: Performance comparison of eight analytical methods

A wide variety of medical devices (MDs) used in hospitals are made of flexible plasticized polyvinylchloride (PVC). Different plasticizers are present in variable amounts in the PVC matrix of the devices and can leach out into the infused solutions and may enter into contact with the patients. The ARMED¹ project aims to assess the migration of these plasticizers from medical devices and therefore the level of exposure in patients. For the first task of the project, eight methods were developed to directly detect and quantify the plasticizers in the PVC matrix of the MDs. We compared the overall performances of the analytical methods using standardized and validated criteria in order to provide the scientific community with the guidance and the technical specifications of each method for the intended application. We have shown that routine rapid screening could be performed directly on the MDs using the FTIR technique, with cost-effective analyses. LC techniques may also be used, but with limits and only with individual quantification of the main plasticizers expected in the PVC matrix. GC techniques, especially GC-MS, are both more specific and more sensitive than other techniques. NMR is a robust and specific technique to precisely discriminate all plasticizers in a MD but is limited by its cost and its low ability to detect and quantify plasticizer contamination, e.g. by DEHP. All these results have been confirmed by a real test, called the " blind test " carried out on 10 MD samples.

L'heuristique d'ancrage et d'ajustement comme mode d'évaluation d'un produit nouveau

L'article montre l'existence d'un autre mode de traitement de l'information fondé sur une heuristique d'ancrage et d'ajustement catégoriel. En s'appuyant sur les schémas catégoriels associés à la marque, le consommateur peut parvenir à une évaluation rapide d'un produit nouveau, et éviter ainsi un traitement approfondi des caractéristiques de l'offre. En fonction du degré de typicalité du produit vis-à-vis des produits de la catégorie activée, la phase d'ancrage peut toutefois être remise en question, le consommateur procédera alors à un ajustement de sa première impression.

Assessment of anti-factor Xa activity of heparin in binary parenteral nutrition admixtures for premature neonates

An in vitro study was carried out to determine the anti-Xa activity of heparin in binary parenteral nutrition (BPN) admixtures for premature neonates in our neonatal intensive care unit (NICU) after a 24-hour infusion, as well as to assess drug interaction with a 50% glucose solution. Two types of bags were prepared: (1) BPN admixtures (composition defined in the NICU) including sodium heparin at 77 UI/mL and (2) bags containing only G50% with sodium heparin at 193 UI/mL. The anti-Xa activity of heparin was measured in bags at T0, after the 24-hour infusion and in eluates at the outlet of the infusion line after 24hours, using a validated chromogenic anti-Xa method. Comparisons of the mean concentration observed with the theoretical value for anti-Xa activity were performed with the Student t-test. Mean values of anti-Xa activity do not differ significantly from the values expected for all conditions. We found a slight variation in anti-Xa activity when infused over 24hours for both types of bags, with and without in-line filtration, showing that heparin remains stable during this infusion period in both BPN admixtures and G50%.

Impact of noradrenaline infusion set on mean arterial pressure: a retrospective clinical study

OBJECTIVES

Noradrenaline (NA) can be infused through various systems including single or double syringe pumps. The aim of this study was to define the best and most efficient infusion system in an emergency context.

STUDY DESIGN

This was a retrospective clinical study based on the analysis of patients' hemodynamic data.

PATIENTS AND METHOD

Three infusion lines used presently in our postoperative ICU were compared through a retrospective clinical study: an NA syringe pump at 2mL/h and a saline carrier solution syringe pump at 8mL/h (infusion system 1- IS1) or 5mL/h (IS2), both connected to a very low dead-space volume set (V=0.046mL); IS3 with the same NA syringe at 2mL/h directly connected to the central venous catheter. Mean arterial pressure (MAP) was obtained from retrospective data analysis of ICU patients with postoperative septic shock criteria. Infusion systems were compared according to the time required to reach an MAP greater than 65mmHg after the onset of infusion.

RESULTS

Data from 37 patients was analysed. The MAP objective was attained in 14:00 minutes (9:20 - 26:10, n=15) with IS1, in 19:10 minutes (12:20 - 27:20, n=13) with IS2 and in 34:10 minutes (23:10 - 62:30, n=9) with IS3 (P=0.00032).

CONCLUSION

The use of a double syringe pump system associated with a very low dead-space volume infusion set appears to be the most appropriate system for NA infusion.

[Preliminary assessment of the use of portable hydrogen peroxide detectors in a centralized cytotoxic preparation unit]

INTRODUCTION

For 1 year, our unit has been equipped with portable H₂O₂ Dräger detectors contributing to protect the staff from a possible exposure to this odourless and toxic gas. This work shows the current available data about H₂O₂ toxicity, describes the organization of the implementation and the analysis of the values measured over 12 months.

MATERIAL AND METHODS

Data about H₂O₂ toxicity have been obtained through a literature review. The measured values are presented in instantaneous value and occupational exposure limit (OEL) over 8 h.

RESULTS

Over six technicians, the average percentage, of detected values superior to zero reached 1.06% in August. The detected maximum instantaneous value reached 2.2 ppm in May. These isolated exposures have little incidence when related to the 8-h exposure with an occupational exposure limit (OEL) of 0.072 ppm over 12 months.

DISCUSSION AND CONCLUSION

The implementation of this tool has allowed to highlight a technical problem of the sterilization airlock that could be resolved. This measuring device of H₂O₂ concentration in the air in real time allows to secure everyday working conditions and to alert the staff of a possible technical failure. However, literature data regarding chronic toxicity are limited and restrict the analysis of the measured values.

[Major haemodynamic incident during continuous norepinephrine infusion: Beware of the infusion line. An avoidable postoperative hypertensive peak?]

The restoration of patients' mean arterial pressure after ineffective fluid resuscitation is obtained by vasopressive treatment such as norepinephrine. However, no guidelines exist concerning a norepinephrine infusion method: whether it be the norepinephrine concentration in the syringe, single or double pump administration via a carrier such as an isotonic saline solution, or use of minimized dead-volume extension sets. We present the case of a female patient requiring norepinephrine treatment, who quickly suffers a major haemodynamic incident (a sudden rise in systolic blood pressure above 220 mmHg associated with tachycardia up to 189 b/min). The main causes of this incident are discussed and infusion parameters considered with a view to developing an optimal infusion method for a drug with a specific therapeutic index.

Chronic dialysis-associated anaemia in end-stage renal disease: analysis of management in two French centres

BACKGROUND

Treatment of anaemia in renal-insufficient patients relies on the use of an erythropoiesis-stimulating agent (ESA). This study aimed to compare the impact of two different strategies of ESA prescribing on variation in haemoglobin (Hb) concentration in end-stage renal disease (ESRD) patients.

METHODS

Patients with ESRD, on haemodialysis, and who had received ESA for >3 months were recruited. Different parameters were analysed: demographics, Hb level the last day of the year before dialysis, the most recent weekly ESA dose, risk factors for resistance and cost. Each institution continued its local practice for achieving the desired Hb level: increasing the ESA dose to overcome resistance in one centre and defining an upper ESA-dose limit in the other.

RESULTS

A total of 185 patients were recruited. No significant differences in the biological parameters were found between the two populations. In both centres, Hb levels were comparable and mean levels exceeded 11 g/dL, despite the higher ESA doses given in one centre to achieve this target. This finding also held true for the subgroups with greater than or equal to two resistance factors. These two strategies led to large between-centre differences in treatment costs.

CONCLUSION

The ESA-use strategy difference probably indicates that erythropoietin-resistance was not overcome with increased dosing. The Hb concentrations remained stable even when ESA doses were increased. On current evidence, the cheaper ESA-dose limitation strategy is preferable but randomized controlled studies, including comparisons of alternative ESA formulations are necessary.

[Humidification assessment of four heat and moisture exchanger filters according to ISO 9360: 2000 standard]

OBJECTIVE

This work consisted of the assessment of humidification parameters and flow resistance for different heat and moisture exchanger filters (HMEF) used in intensive care unit. Four electrostatic HMEF were assessed: Hygrobac S (Tyco); Humidvent compact S (Teleflex); Hygrovent S/HME (Medisize-Dräger); Clear-Therm+HMEF (Intersurgical).

MATERIAL AND METHODS

Humidification parameters (loss of water weight, average absolute moisture [AAM], absolute variation of moisture) have been evaluated on a bench-test in conformity with the ISO 9360: 2000 standard, for 24h with the following ventilatory settings: tidal volume at 500 ml, respiratory rate at 15 c/min, and inspiration/expiration ratio at 1:1. The flow resistance of HMEFs assessed using the pressure drop method was measured before and after 24h of humidification for three increasing air flows of 30, 60, and 90 l/min.

RESULTS

All the HMEFs allowed satisfactory level of humidification exceeding 30 mgH(2)O/l. The less powerful remained the Clear-Therm. Concerning HMEFs flow resistance, results showed a pressure drop slightly more important for the Hygrobac S filter as compared with other filters.

CONCLUSION

This test showed differences between the HMEFs for both humidification and resistance parameters. When compared to the new version of the standards, HMEFs demonstrated their reliability. However, evolution of humidification and flow resistance characteristics over 24h showed a structural degradation of HMEFs, limiting their use over a longer period.

Gemtuzumab ozogamicin-induced sinusoidal obstructive syndrome treated with defibrotide: a case report

New treatments for relapse of acute myeloid leukaemia (AML), include gemtuzumab ozogamicin (GO), an anti-CD33 monoclonal antibody. We describe a second case of GO-induced sinusoidal obstructive syndrome (SOS) effectively treated with defibrotide (DF). No stem-cell transplantation was involved. On day 23 after the first GO dose, a patient presented with ascites, weight gain, liver enlargement and pain in the right upper quadrant. Sudden hepatic cytolysis (transaminases at six times the normal range: grade 3) and cholestasis [alkaline phosphatase ALP and gamma-glutamyltransferase (GGT) respectively at four and eight times the normal range: grade 2] were observed but there was no evidence of increase serum bilirubin. Treatment with DF (Prociclide), Crinos; 10 mg/kg/day, or 200 mg, q.i.d.) improved the hepatic abnormality within a few days (serum transaminases decreased from 312 to 103 IU/L for aspartate aminotransferase (AST) and from 141 to 80 IU/L for alanine aminotransferase (ALT) within 3 days ALP increased from 253 to 383 IU/L and gamma-GT from 238 to 417 IU/L 4 days after administration of DF. The clinical and biological features of our case suggest a direct involvement of GO in causing SOS, even when used as monotherapy, without allogenic stem-cell transplantation. Low dose DF (10 mg/kg/day) given early during the development of SOS associated with GO was effective. Unfortunately, in our case the patient eventually died of multi-organ failure probably because of failure of GO.

[Spontaneously acquired haemophilia: report of a patient with prostatic adenoma]

We report the case of a 86-year-old man admitted in a local hospital with spontaneous haematoma, an isolated prolonged activated partial prothrombin time (114/32 seconds; ratio = 3.6), an anemia and a normal platelet count. Two diagnosis were suspected: a coagulation factor defect, or the presence of a lupus anticoagulant or of anti-factor antibodies. An acquired haemophilia A was confirmed with a factor VIII activity level < 1 U/dL associated with the presence of an anti-factor VIII inhibitor. The factor VIII inhibitor titer reached 195 Bethesda U/mL. A prostatic adenocarcinoma was suspected: a 5 cm prostatic tumour was found and the PSA level was 113 ng/mL. The patient was treated with recombinant factor VIIa: Novoseven (90 microg/kg). None immunosuppressive agents were prescribed in this elderly patient. The patient's disease was identified as a spontaneously acquired haemophilia A associated with prostatic adenocarcinoma.

Grapefruit juice-nifedipine interaction: possible involvement of several mechanisms

OBJECTIVE

To develop a model based on mean residence time for better understanding the effect of grapefruit juice on the metabolism of nifedipine (NIF).

MATERIAL AND METHODS

Sixteen healthy volunteers from an urban population were included. For each trial, the subjects drank water, fresh grapefruit juice or bottled grapefruit juice. Thirty minutes later, the subjects took a 10 mg capsule of NIF, orally. Plasma concentration of NIF was measured and the kinetic parameters were calculated with a non-compartmental model.

RESULTS

Grapefruit juice increased the bioavailability of NIF, but did not significantly reduce the drug's metabolism as shown by the approximately constant metabolite to parent drug AUC ratio (P = 0.948). There was no significant increase in the amount of non-metabolized drug absorbed during first-pass: 0.12 and 0.16 (P = 0.470) without and with grapefruit juices respectively. There was an increase in the relative bioavailability (P = 0.039) and the apparent volume of distribution (Vdm) (P = 0.025) of dehydronifedipine with grapefruit co-administration. A second peak was also observed in the NIF plasma-concentration profile when the drug is co-administered with grapefruit juice. Therefore, the most likely explanation for the double peak phenomenon is a delay in gastric emptying (+32 min with grapefruit juice) caused by the pH of grapefruit juice.

CONCLUSION

This study shows that grapefruit juice interferes with the metabolism of NIF by inhibiting NIF metabolism and slowing down the rate of gastric emptying. This study also confirms that the metabolic inhibition is not a first pass effect, but is a secondary oxidative step.

LC determination of oxcarbazepine and its active metabolite in human serum

Twenty-five percent of epileptic patients present refractory seizures to current frontline antiepileptic drugs, needing new treatments and leading to the introduction of several new AEDs, among which is oxcarbazepine (Trileptal). This 10-ketoanalogue of carbamazepine seems to be a weaker inducer of cytochrome P450 3A4. However, pharmacokinetic interactions with clinical significance have already been reported, before the marketing of Trileptal in France. The aim of this study was to develop and validate a HPLC method allowing simultaneous dosage of oxcarbazepine, 10-hydroxycarbamazepine, epoxycarbamazepine, carbamazepine, phenobarbital and phenytoïn. After plasma defecation by acetonitrile, dosage was obtained by analysis of the supernatants on a C(18) reversed-phase column coupled with UV detection (240 nm). The statistical validation was performed according to the recommendations of a European technical commission. This method seems to provide a quite good selectivity from the psychotropic therapeutics, which is commonly coprescribed with AEDs. Linearity was established for the whole concentration range, whatever the compound. Quantization limits of oxcarbazepine, 10-hydroxycarbamazepine, epoxycarbamazepine, carbamazepine, phenobarbital and phenytoïn are 0.58, 3.5, 2.35, 0.66, 1.02 and 3.13 microg/ml, respectively, and absolute recoveries are 105.15, 84.76, 94.45, 96.52, 98.62 and 95.08%, respectively.