A single LC-tandem mass spectrometry method for the simultaneous determination of 14 antimalarial drugs and their metabolites in human plasma.

Among the various determinants of treatment response, the achievement of sufficient blood levels is essential for curing malaria. For helping us at improving our current understanding of antimalarial drugs pharmacokinetics, efficacy and toxicity, we have developed a liquid chromatography-tandem mass spectrometry method (LC-MS/MS) requiring 200mul of plasma for the simultaneous determination of 14 antimalarial drugs and their metabolites which are the components of the current first-line combination treatments for malaria (artemether, artesunate, dihydroartemisinin, amodiaquine, N-desethyl-amodiaquine, lumefantrine, desbutyl-lumefantrine, piperaquine, pyronaridine, mefloquine, chloroquine, quinine, pyrimethamine and sulfadoxine). Plasma is purified by a combination of protein precipitation, evaporation and reconstitution in methanol/ammonium formate 20mM (pH 4.0) 1:1. Reverse-phase chromatographic separation of antimalarial drugs is obtained using a gradient elution of 20mM ammonium formate and acetonitrile both containing 0.5% formic acid, followed by rinsing and re-equilibration to the initial solvent composition up to 21min. Analyte quantification, using matrix-matched calibration samples, is performed by electro-spray ionization-triple quadrupole mass spectrometry by selected reaction monitoring detection in the positive mode. The method was validated according to FDA recommendations, including assessment of extraction yield, matrix effect variability, overall process efficiency, standard addition experiments as well as antimalarials short- and long-term stability in plasma. The reactivity of endoperoxide-containing antimalarials in the presence of hemolysis was tested both in vitro and on malaria patients samples. With this method, signal intensity of artemisinin decreased by about 20% in the presence of 0.2% hemolysed red-blood cells in plasma, whereas its derivatives were essentially not affected. The method is precise (inter-day CV%: 3.1-12.6%) and sensitive (lower limits of quantification 0.15-3.0 and 0.75-5ng/ml for basic/neutral antimalarials and artemisinin derivatives, respectively). This is the first broad-range LC-MS/MS assay covering the currently in-use antimalarials. It is an improvement over previous methods in terms of convenience (a single extraction procedure for 14 major antimalarials and metabolites reducing significantly the analytical time), sensitivity, selectivity and throughput. While its main limitation is investment costs for the equipment, plasma samples can be collected in the field and kept at 4 degrees C for up to 48h before storage at -80 degrees C. It is suited to detecting the presence of drug in subjects for screening purposes and quantifying drug exposure after treatment. It may contribute to filling the current knowledge gaps in the pharmacokinetics/pharmacodynamics relationships of antimalarials and better define the therapeutic dose ranges in different patient populations.

Impact of international consensus guidelines on antiviral therapy of chronic hepatitis C patients in Switzerland.

To assess the impact of international consensus conference guidelines on the attitude of Swiss specialists when facing the decision to treat chronic hepatitis C patients. Questionnaires focusing on the personal situation and treatment decisions were mailed to 165 patients who were newly diagnosed with hepatitis C virus (HCV) infection and enrolled into the Swiss Hepatitis C Cohort Study during the years 2002-2004. Survey respondents (n = 86, 52.1%) were comparable to non-respondents with respect to severity of liver disease, history of substance abuse and psychiatric co-morbidities. Seventy percent of survey respondents reported having been offered antiviral treatment. Patients deferred from treatment had less advanced liver fibrosis, were more frequently infected with HCV genotypes 1 or 4 and presented more often with a history of depression. There were no differences regarding age, socio-economic background, alcohol abuse, intravenous drug abuse or methadone treatment when compared with patients to whom treatment was proposed. Ninety percent of eligible patients agreed to undergo treatment. Overall, 54.6% of respondents and 78.3% of those considered eligible had actually received antiviral therapy by 2007. Ninety-five percent of patients reported high satisfaction with their own hepatitis C management. Consistent with latest international consensus guidelines, patients enrolled in the Swiss Hepatitis C Cohort with a history of substance abuse were not withheld antiviral treatment. A multidisciplinary approach is warranted to provide antiviral treatment to patients suffering from depression.

Swallowing difficulties with oral drugs among polypharmacy patients attending community pharmacies.

Background Swallowing difficulties are common and can affect patients' ability to take solid oral dosage forms, thus compromising medication adherence. Strategies developed by patients to overcome such difficulties while taking medicines have seldom been described. Objective To determine prevalence and characteristics of swallowing difficulties among primary care patients attending their community pharmacies; to explore strategies developed by patients to overcome their difficulties, and health professionals' awareness of these problems. Setting Prospective study with a semi-structured questionnaire in random community pharmacies located in two Swiss regions. Method In each pharmacy, an interviewer asked 16 questions to each consecutive patient (18 years and older) with a prescription for at least 3 different solid oral forms. Main outcome measure Quantification of number of patients with swallowing difficulties and detailed description of difficulties. Results Among 122 pharmacies, 59 (48 %) accepted to join the study and 410 patients were enrolled. Thirty-seven patients (9.0 %) reported ongoing swallowing difficulties, while 55 patients (13.4 %) reported past difficulties. For the majority of patients, difficulties occurred at each single dose (83.7 %), with a single medication (59.8 %) and lasted for less than 12 months (53.8 %). Number of tablets was not the main trigger. Swallowing difficulties impaired extremely daily life in 12 % of the patients. Intentional non adherence (23 % of patients) and altering the oral dose formulation were the most common and potentially harmful strategies used by patients to overcome their swallowing difficulties. According to the patients, pharmacists and physicians rarely inquired about their swallowing difficulties. Conclusion We report a fairly high prevalence of swallowing difficulties in polypharmacy patients attending their community pharmacies. Pharmacists have to interview patients on their swallowing difficulties in a more systematic way, support patients in finding solutions and refer them to their physician if necessary to ensure continuity in care.

Use of neuroenhancement drugs: prevalence, frequency and use expectations in Switzerland

Objective: The present study investigates the use expectations, prevalence and frequency of neuroenhancement drug (ND) use among the Swiss male population, separating college students from others. Methods: Young Swiss men were invited to participate in the Cohort Study on Substance Use Risk Factors. A total of 5,967 participants responded to questions on six types of NDs (wakefulness medication, antidepressants, Alzheimer's disease medication, Parkinson's disease medication, attention deficit-hyperactivity disorder (ADHD) medication, and beta-blockers). The frequency of use depending on five expectations (to enhance wakefulness, attention, memory, concentration and stress reduction) was analyzed for a twelve-month period. Results: (1) About 3% of the sample indicated use of at least one ND; (2) ADHD medication was the most prevalent; (3) The type of ND preferred differed depending on academic status (4). Quantitatively, over the year, college student users used ND much less frequently than other users. Conclusions: Prevalence of ND use is low in Switzerland relative to other countries such as the United States. Patterns of ND use differed depending on academic status, suggesting that while college student ND users tended to do so rarely (probably to enhance cognitive abilities for exams), non-college male users used other NDs more frequently (probably to "get high").

Antiretroviral treatment of adult HIV infection: 2014 recommendations of the International Antiviral Society-USA Panel.

IMPORTANCE: New data and antiretroviral regimens expand treatment choices in resource-rich settings and warrant an update of recommendations to treat adults infected with human immunodeficiency virus (HIV). OBJECTIVE: To provide updated treatment recommendations for adults with HIV, emphasizing when to start treatment; what treatment to start; the use of laboratory monitoring tools; and managing treatment failure, switches, and simplification. DATA SOURCES, STUDY SELECTION, AND DATA SYNTHESIS: An International Antiviral Society-USA panel of experts in HIV research and patient care considered previous data and reviewed new data since the 2012 update with literature searches in PubMed and EMBASE through June 2014. Recommendations and ratings were based on the quality of evidence and consensus. RESULTS: Antiretroviral therapy is recommended for all adults with HIV infection. Evidence for benefits of treatment and quality of available data increase at lower CD4 cell counts. Recommended initial regimens include 2 nucleoside reverse transcriptase inhibitors (NRTIs; abacavir/lamivudine or tenofovir disoproxil fumarate/emtricitabine) and a third single or boosted drug, which should be an integrase strand transfer inhibitor (dolutegravir, elvitegravir, or raltegravir), a nonnucleoside reverse transcriptase inhibitor (efavirenz or rilpivirine) or a boosted protease inhibitor (darunavir or atazanavir). Alternative regimens are available. Boosted protease inhibitor monotherapy is generally not recommended, but NRTI-sparing approaches may be considered. New guidance for optimal timing of monitoring of laboratory parameters is provided. Suspected treatment failure warrants rapid confirmation, performance of resistance testing while the patient is receiving the failing regimen, and evaluation of reasons for failure before consideration of switching therapy. Regimen switches for adverse effects, convenience, or to reduce costs should not jeopardize antiretroviral potency. CONCLUSIONS AND RELEVANCE: After confirmed diagnosis of HIV infection, antiretroviral therapy should be initiated in all individuals who are willing and ready to start treatment. Regimens should be selected or changed based on resistance test results with consideration of dosing frequency, pill burden, adverse toxic effect profiles, comorbidities, and drug interactions.

Drug monographs on drugs which are frequently analysed in the context of Therapeutic Drug Monitoring = Arzneimittel-Monographien für Medikamente, die regelmässig im Rahmen des Therapeutic Drug Monitorings analysiert werden

In addition to the monographs which were published last year by the working group "Drug Monitoring" of the Swiss Society of Clinical Chemistry (SSCC) [1], new monographs have been written. The aim of these monographs is to give an overview of the most important information necessary for ordering a drug analysis or interpreting the results. Therefore, the targeted readers comprise laboratory health professionals and all receivers of laboratory reports. There is information provided on the indication for therapeutic drug monitoring, protein binding, metabolic pathways and enzymes involved, elimination half-life and elimination routes, and on therapeutic or toxic concentrations. Preanalytical considerations are of particular importance for therapeutic drug monitoring. Therefore, information is provided regarding a reasonable timing for the determination of drug concentrations as well as steady-state concentrations after changing the dose. Furthermore, the stability of the drug and its metabolite(s) after blood sampling is described. For readers with a specific interest in drug analysis, references to important publications are given. The number of monographs will be continuously enlarged. The updated files are presented on the homepage of the SSCC (www.sscc.ch).

The impact of newer antiepileptic drugs in the treatment of status epilepticus

Purpose: Newer antiepileptic drugs (AED) are increasingly prescribed, and seem to have a comparable efficacy as the classical AED in patients living with epilepsy; however, their impact on status epilepticus (SE) prognosis has received little attention. Method: In our prospective SE registry (2006-10) we assessed the use of newer AED (for this purpose: levetiracetam, pregabalin, topiramate, lacosamide) over time, and its relationship to outcome (return to clinical baseline conditions, new handicap, or death). We adjusted for recognized SE outcome predictors (Status Epilepticus Severity Score, STESS; potentially fatal etiology), and the use of >2 AED for a given SE episode. Result: Newer AED were used more often towards the end of the study period (42% versus 30% episodes), and more frequently in severe and difficult to treat episodes. However, after adjustment for SE etiology, STESS, and medication number, newer AED resulted independently related to reduced likelihood of return to baseline (p < 0.01), but not to increased mortality. STESS and etiology were robustly related to both outcomes (p < 0.01 for each), while prescription of >2 AED was only related to lower chance of return to baseline (p = 0.03). Conclusion: Despite increase in the use of newer AED, our findings suggest that SE prognosis has not been improved. This appears similar to recent analyses on patients with refractory epilepsy, and corroborates the hypothesis that SE prognosis is mainly determined by its biological background. Since newer AED are more expensive, prospective trials showing their superiority (at least regarding side effects) appear mandatory to justify their use in this setting.

Newer antiepileptic drugs in the treatment of status epilepticus: impact on prognosis

Background: Newer antiepileptic drugs (AED) are increasingly prescribed, and seem to have a comparable efficacy as the classical AED, but are better tolerated. Very scarce data exist regarding their prognostic impact in patients with status epilepticus (SE). We therefore analyzed the evolution of prescription of newer AED between 2006-2010 in our prospective SE database, and assessed their impact on SE prognosis.¦Methods: We found 327 SE episodes occurring in 271 adults. The use of older versus newer AED (levetiracetam, pregabalin, topiramate, lacosamide) and its relationship to outcome (return to clinical baseline conditions, new handicap, or death) were analyzed. Logistic regression models were applied to adjust for known SE outcome predictors.¦Results: We observed an increasing prescription of newer AED over time (30% of patients received them at the study beginning, vs. 42% towards the end). In univariate analyses, patients treated with newer AED had worse outcome than those treated with classical AED only (19% vs 9% for mortality; 33% vs 64% for return to baseline, p<0.001). After adjustment for etiology and SE severity, use of newer AED was independently related to a reduced likelihood of return to baseline (p<0.001), but not to increased mortality.¦Conclusion: This retrospective study shows an increase of the use of newer AED for SE treatment, but does not suggest an improved prognosis following their prescription. Also in view of their higher price, well-designed, prospective assessments analyzing their impact on efficacy and tolerability should be conducted before a widespread use in SE.

Sequence-Based Hepatitis B Virus Antiviral Resistance Testing in Switzerland

BACKGROUND: A growing number of patients with chronic hepatitis B is being treated for extended periods with nucleoside and/or nucleotide analogs. In this context, antiviral resistance represents an increasingly common and complex issue. METHODS: Mutations in the hepatitis B virus (HBV) reverse transcriptase (rt) gene and viral genotypes were determined by direct sequencing of PCR products and alignment with reference sequences deposited in GenBank. RESULTS: Plasma samples from 60 patients with chronic hepatitis B were analyzed since March 2009. The predominant mutation pattern identified in patients with virological breakthrough was rtM204V/I ± different compensatory mutations, conferring resistance to L-nucleosides (lamivudine, telbivudine, emtricitabine) and predisposing to entecavir resistance (n = 18). Complex mutation patterns with a potential for multidrug resistance were identified in 2 patients. Selection of a fully entecavir resistant strain was observed in a patient exposed to lamivudine alone. Novel mutations were identified in 1 patient. Wild-type HBV was identified in 9 patients with suspected virological breakthrough, raising concerns about treatment adherence. No preexisting resistance mutations were identified in treatment-naïve patients (n = 13). Viral genome amplification and sequencing failed in 16 patients, of which only 2 had a documented HBV DNA > 1000 IU/ml. HBV genotypes were D in 28, A in 6, B in 4, C in 3 and E in 3 patients. Results will be updated in August 2010 and therapeutic implications discussed. CONCLUSIONS: With expanding treatment options and a growing number of patients exposed to nucleoside and/or nucleotide analogs, sequence-based HBV antiviral resistance testing is expected to become a cornerstone in the management of chronic hepatitis B.

Ampakine CX546 bolsters energetic response of astrocytes: a novel target for cognitive-enhancing drugs acting as alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor modulators.

Glutamate was previously shown to enhance aerobic glycolysis i.e. increase glucose utilization and lactate production with no change in oxygen levels, in mouse cortical astrocytes by a mechanism involving glutamate uptake. It is reported here that a similar response is produced in both hippocampal and cerebellar astrocytes. Application of the cognitive-enhancing drug CX546 promoted further enhancement of glucose utilization by astrocytes from each brain area following glutamate exposure. alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors represent the purported molecular target of cognitive-enhancing drugs such as CX546, and the presence of AMPA receptor subunits GluR1-4 was evidenced in astrocytes from all three regions by immunocytochemistry. AMPA itself did not stimulate aerobic glycolysis, but in the presence of CX546, a strong enhancement of glucose utilization and lactate production was obtained in cortical, hippocampal and cerebellar astrocytes. The effect of CX546 was concentration-dependent, with an EC(50) of 93.2 microm in cortical astrocytes. AMPA-induced glucose utilization in the presence of CX546 was prevented by the AMPA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and the negative modulator GYKI 52466. In addition, the metabolic effect of CX546 in the presence of AMPA was mimicked by the AMPA receptor modulator cyclothiazide. Our data suggest that astrocyte energetics represents a novel target for cognitive-enhancing drugs acting as AMPA receptor modulators.