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1.
Eur J Clin Pharmacol ; 69(5): 1127-34, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23131857

RESUMO

BACKGROUND: The area under the concentration-time curve (AUC) after oral midazolam administration is commonly used for cytochrome P450 (CYP) 3A phenotyping studies. The aim of this investigation was to evaluate a limited sampling strategy for the prediction of AUC with oral midazolam. METHODS: A total of 288 concentration-time profiles from 123 healthy volunteers who participated in four previously performed drug interaction studies with intense sampling after a single oral dose of 7.5 mg midazolam were available for evaluation. Of these, 45 profiles served for model building, which was performed by stepwise multiple linear regression, and the remaining 243 datasets served for validation. Mean prediction error (MPE), mean absolute error (MAE) and root mean squared error (RMSE) were calculated to determine bias and precision RESULTS: The one- to four-sampling point models with the best coefficient of correlation were the one-sampling point model (8 h; r (2) = 0.84), the two-sampling point model (0.5 and 8 h; r (2) = 0.93), the three-sampling point model (0.5, 2, and 8 h; r (2) = 0.96), and the four-sampling point model (0.5,1, 2, and 8 h; r (2) = 0.97). However, the one- and two-sampling point models were unable to predict the midazolam AUC due to unacceptable bias and precision. Only the four-sampling point model predicted the very low and very high midazolam AUC of the validation dataset with acceptable precision and bias. The four-sampling point model was also able to predict the geometric mean ratio of the treatment phase over the baseline (with 90 % confidence interval) results of three drug interaction studies in the categories of strong, moderate, and mild induction, as well as no interaction. CONCLUSION: A four-sampling point limited sampling strategy to predict the oral midazolam AUC for CYP3A phenotyping is proposed. The one-, two- and three-sampling point models were not able to predict midazolam AUC accurately.


Assuntos
Área Sob a Curva , Citocromo P-450 CYP3A/genética , Modelos Lineares , Midazolam/farmacocinética , Fenótipo , Administração Oral , Adulto , Feminino , Humanos , Masculino , Midazolam/administração & dosagem
2.
Phytother Res ; 27(2): 199-204, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22517542

RESUMO

Bromelain has been used for treatment of inflammatory diseases for decades. However, the exact mechanism of action remains poorly understood. While in vitro investigations have shown conflicting effects on the release of various cytokines, no in vivo data were available. In this study, the effects on inflammation-related cytokines of two doses of bromelain were tested in a single dose placebo-controlled 3 × crossover randomized clinical trial. Cytokine circadian profiles were used to investigate the effects of bromelain on the human immune system by using stimulated whole-blood leukocytes. The effects seen in these cultures demonstrated a significant shift in the circadian profiles of the Th1 cell mediator interferon gamma (IFNγ; p < 0.043) after bromelain 3000 FIP (Fédération Internationale Pharmaceutique) units, and trends in those of the Th2-type cytokine IL-5 as well as the immunosuppressive cytokine interleukin (IL)-10. This suggests a general effect on the antigen-specific (T cell) compartment of the human immune system. This is the first time that bromelain has been shown to modulate the cellular responses of lymphocyte after oral use. It is postulated that the immunomodulating effect of bromelain observed in this trial is part of its known antiinflammatory activities. Further investigations will be necessary to verify the relevance of these findings to a diseased immune system.


Assuntos
Anti-Inflamatórios/farmacologia , Bromelaínas/farmacologia , Linfócitos/efeitos dos fármacos , Administração Oral , Adulto , Células Cultivadas , Ritmo Circadiano , Estudos Cross-Over , Humanos , Interferon gama/imunologia , Interleucina-10/imunologia , Interleucina-5/imunologia , Linfócitos/imunologia , Masculino , Adulto Jovem
3.
Biol Blood Marrow Transplant ; 18(7): 1061-8, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22182476

RESUMO

Everolimus (RAD001) is an mTOR inhibitor that has been successfully used as an immunosuppressant in solid-organ transplantation. Data in allogeneic hematopoietic stem cell transplantation (HSCT) is limited. This study aimed to investigate pharmacokinetics, safety, and efficacy of RAD001 in a canine allogeneic HSCT model. First, pharmacokinetics of RAD001 were performed in healthy dogs in order to determine the appropriate dosing. Doses of 0.25 mg RAD001 twice daily in combination with 15 mg/kg cyclosporin A (CsA) twice daily were identified as appropriate starting doses to achieve the targeted range of RAD001 (3-8 µg/L) when orally administered. Subsequently, 10 dogs were transplanted using 2 Gy total body irradiation (TBI) for conditioning and 0.25 mg RAD001 twice daily plus 15 mg/kg CsA twice daily for pre- and posttransplantation immunosuppression. Seven of the 10 transplanted dogs were maintained at the starting RAD001 dose throughout the study. For the remaining 3 dogs, dose adjustments were necessary. RAD001 accumulation over time did not occur. All dogs initially engrafted. Five dogs eventually rejected the graft (weeks 10, 10, 13, 27, and 56). Two dogs died of pneumonia (weeks 8 and 72) but were chimeric until then. Total cholesterol rose from median 4.1 mmol/L (3.5-5.7 mmol/L) before HSCT to 6.0 mmol/l (5.0-8.5 mmol/l) at day 21 after HSCT, but remained always within normal range. Changes in creatinine and triglyceride values were not observed. Long-term engraftment rates were inferior to sirolimus/CsA and mycophenolate mofetil (MMF)/CsA regimen, respectively. RAD001/CsA caused a more pronounced reduction of platelet counts to median 2 × 10(9)/L (range: 0-21 × 10(9)/L) and longer time to platelet recovery of 21 days (range: 14-24 days) compared with MMF/CsA. CsA c(2h) levels were significantly enhanced in the RAD001/CsA regimen, but c(0h) and area under the curve from 0 to 12 hours (AUC(0-12h)) values did not differ compared with an MMF/CsA immunosuppression. In summary, immunosuppression consisting of RAD001 and CsA is well tolerated but not as efficient as with other established immunosuppressants in a canine nonmyeloablative HSCT regimen. Hence, our study does not support the application of RAD001/CsA as standard practice in this setting.


Assuntos
Ciclosporina/farmacocinética , Rejeição de Enxerto/prevenção & controle , Transplante de Células-Tronco Hematopoéticas , Imunossupressores/farmacocinética , Ácido Micofenólico/análogos & derivados , Sirolimo/análogos & derivados , Sirolimo/farmacocinética , Animais , Área Sob a Curva , Plaquetas/imunologia , Plaquetas/patologia , Colesterol/sangue , Ciclosporina/uso terapêutico , Cães , Combinação de Medicamentos , Everolimo , Rejeição de Enxerto/sangue , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Imunossupressores/uso terapêutico , Ácido Micofenólico/farmacocinética , Ácido Micofenólico/uso terapêutico , Contagem de Plaquetas , Sirolimo/uso terapêutico , Condicionamento Pré-Transplante/métodos , Transplante Homólogo , Irradiação Corporal Total
4.
BMC Med Res Methodol ; 12: 112, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22853196

RESUMO

BACKGROUND: The variation of immune cell activities over time is an immanent property of the human immune system, as can be measured by the stimulated secretion of cytokines in cell cultures. However, inter-individual variability is considerably higher. Especially the latter is the major reason why it has not been possible to establish international standard values for cytokines as was possible for other parameters, such as leukocyte sub-population numbers. In this trial, a highly standardized whole-blood culture model (TrueCulture®), developed to characterise drug effects on cells of the human immune system in clinical trials, was used to analyse cytokine patterns in the blood samples of 12 healthy subjects over a period of one month. METHODS: After an overnight fast, 12 healthy subjects donated blood three times a week on three consecutive days over a period of 4 weeks. TruCulture® blood collection and whole-blood culture systems were used to measure whole-blood leukocyte stimulation. The levels of IL-2, IL-5, IL-13, IL-6, IL-8, IL-10, IFNγ, and MCP-1 in the culture supernatants were quantified by sandwich ELISA. RESULTS: The pattern of cytokine concentrations in the supernatants of the stimulated whole-blood cultures was highly individual, but considerably stable over the whole observation period of 4 weeks. CONCLUSIONS: By using TruCulture® it seems feasible to determine subject-specific cytokine reference patterns, for example under healthy conditions, or before starting an experimental treatment, e.g. during a clinical trial, against which changes in the behaviour of the immune system can be detected more accurately in future.


Assuntos
Acesso à Informação , Dor nas Costas/psicologia , Acessibilidade aos Serviços de Saúde , Saúde da População Rural/normas , Autocuidado , Adulto , Idoso , Dor nas Costas/terapia , Feminino , Indicadores Básicos de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Socioeconômicos , Austrália Ocidental
5.
Eur J Clin Pharmacol ; 67(2): 135-42, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20871984

RESUMO

OBJECTIVES: Physiological changes occurring in patients with diabetes may affect the pharmacokinetics and penetration of antimicrobial agents into peripheral tissue. We examined the pharmacokinetics and the penetration of moxifloxacin into perinecrotic tissue of diabetic foot lesions in patients with diabetic foot infections (DFI). PATIENTS AND METHODS: Adult patients suffering from type 2 diabetes mellitus and hospitalized for DFI (Texas classification of at least B2) were treated with 400 mg moxifloxacin intravenously (IV) or orally (PO) once daily. The pharmacokinetics of moxifloxacin and its concentration 3 h after administration in samples of perinecrotic tissue resected from infected diabetic foot wounds were determined at steady state (days 4-8). RESULTS: A total of 53 patients with diabetes mellitus type 2 (mean age 69.4 ± 10.8 years) were included in the study, of whom 28 received PO and 25 IV moxifloxacin therapy for a median of 8 days. In the PO and IV subgroups, the mean maximum observed plasma concentration (C (max)) in plasma was 2.69 and 4.77 mg/l at a median of 2 [time to reach C (max) (T (max)) range 1.0-8.0 h] and 1 h after administration, respectively. A mean area under the plasma concentration-time curve from time 0 until the last quantifiable plasma concentration (AUC(0-24 h)) of 29.36 mg h/l (PO) and 27.09 mg h/l (IV) was achieved. Mean moxifloxacin concentrations in perinecrotic tissue of infected diabetic foot wounds following PO or IV administration were 1.79 ± 0.82 and 2.20 ± 1.54 µg/g, thus exceeding the MIC(90) (minimum inhibitory concentration required to inhibit growth of 90% of organisms) for Staphylococcus aureus (0.25 mg/l) by seven- and eightfold and the MIC(90) for Escherichia coli (0.06 mg/l) by 29-fold and 36-fold, respectively. The mean tissue-to-plasma ratios of moxifloxacin concentration 3 h after administration were 1.01 ± 0.57 (PO) and 1.09 ± 0.69 (IV). Significant differences between the routes of administration were observed for T (max) and C (max) (P < 0.01), but not for other clinically relevant parameters (AUC(0-24); moxifloxacin DFI tissue concentration). CONCLUSIONS: The plasma concentration-time curve of moxifloxacin in diabetic patients is similar to that of healthy volunteers. We also observed a good penetration of moxifloxacin into inflamed DFI tissue which taken together with the possibility of sequential IV/PO therapy suggest that moxifloxacin 400 mg once daily is a therapeutic option in the treatment of DFI caused by susceptible organisms.


Assuntos
Anti-Infecciosos/farmacocinética , Compostos Aza/farmacocinética , Diabetes Mellitus Tipo 2/complicações , Pé Diabético/metabolismo , Quinolinas/farmacocinética , Idoso , Idoso de 80 Anos ou mais , Anti-Infecciosos/uso terapêutico , Compostos Aza/uso terapêutico , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/metabolismo , Estudos de Coortes , Diabetes Mellitus Tipo 2/metabolismo , Pé Diabético/tratamento farmacológico , Pé Diabético/microbiologia , Feminino , Fluoroquinolonas , Humanos , Masculino , Pessoa de Meia-Idade , Moxifloxacina , Estudos Prospectivos , Quinolinas/uso terapêutico
6.
Eur J Clin Pharmacol ; 65(1): 81-7, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18762932

RESUMO

OBJECTIVE: Induction of CYP3A by St. John's wort (SJW) products with high hyperforin content is well described. Since CYP3A induction is mediated by hyperforin in a concentration-dependent manner, and SJW preparations differ significantly in hyperforin content, the aim of the study was to evaluate the effect of an SJW powder with low hyperforin content on CYP3A function. METHODS: Twenty healthy male volunteers received an SJW powder with low hyperforin content for 2 weeks. Midazolam plasma concentration time profiles were characterized after a single oral dose of 7.5 mg midazolam on the day before and on the 14th day of SJW medication. RESULTS: Midazolam AUC(0-infinity) slightly decreased from 124.0 +/- 62.5 ng/ml.h at baseline to 105.6 +/- 53.2 ng/ml.h after SJW (P < 0.05), representing a mean 11.3% decrease (95% CI: -22.8 to 0.21). No significant change in midazolam C(max), t(1/2) and t(max) was observed. For all pharmacokinetic parameters, the 90% CI for the geometric mean ratio of treatment over baseline were within the no-effect boundaries of 0.70-1.43. CONCLUSION: Administration of an SJW product with low hyperforin content resulted in a mild induction of CYP3A not considered clinically relevant.


Assuntos
Citocromo P-450 CYP3A/biossíntese , Hypericum , Floroglucinol/análogos & derivados , Preparações de Plantas/farmacologia , Terpenos/farmacologia , Administração Oral , Adulto , Compostos Bicíclicos com Pontes/administração & dosagem , Compostos Bicíclicos com Pontes/análise , Compostos Bicíclicos com Pontes/farmacologia , Estudos Cross-Over , Indução Enzimática , Interações Ervas-Drogas , Humanos , Masculino , Midazolam/administração & dosagem , Midazolam/farmacocinética , Floroglucinol/administração & dosagem , Floroglucinol/análise , Floroglucinol/farmacologia , Preparações de Plantas/administração & dosagem , Preparações de Plantas/química , Pós , Especificidade por Substrato , Terpenos/administração & dosagem , Terpenos/análise , Adulto Jovem
7.
J Clin Pharmacol ; 59(10): 1405-1414, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31111505

RESUMO

Postoperative local infection is a major complication after pancreatic surgery. The aim of this prospective clinical trial was to assess the potential of moxifloxacin (MXF) to treat pancreatic infections from a pharmacokinetic (PK)/pharmacodynamic (PD) perspective. The PK of MXF in serum and pancreatic juice, via an inserted tube in the pancreatic duct, was determined in 19 patients up to day 7 after pancreatoduodenectomy. PK data in both specimens was analyzed with NONMEM 7.3. Intraoperative swipes were performed for microbiological examination. PK/PD target attainment was assessed in both matrices using unbound area under the plasma concentration-time curve/minimum inhibitory concentration (MIC) targets of ≥30 and ≥100, for gram-positive and gram-negative pathogens, respectively. A 2-compartment population PK model in which the measurements in pancreatic juice were assigned to a scaled peripheral compartment best described the PK in both specimens simultaneously. Median (10th-90th percentile) area under the plasma concentration-time curve values after the third dose were 28.9 mg · h/L (18.6-42.0) in serum and 55.8 mg · h/L (23.7-81.4) in pancreatic juice. Target attainment rate for the intraoperatively isolated bacterial strains was ≥0.88 after the third MXF dose. For gram-negatives, high probability of target attainment ≥0.84 was observed in serum for MIC ≤ 0.125 mg/L and in pancreatic juice for MIC ≤ 0.25 mg/L. For gram-positives, the probability of target attainment was 0.84-1 in serum for MIC ≤ 0.5 mg/L and in pancreatic juice for MIC ≤ 1 mg/L. In conclusion, penetration of MXF into pancreatic juice was substantial. The PK/PD analysis indicated that treatment of pancreatic infections by isolates with MIC ≤ 0.25 mg/L (gram-negative) and ≤1 mg/L (gram-positive) should be evaluated in further studies.


Assuntos
Antibacterianos/farmacocinética , Antibacterianos/uso terapêutico , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Moxifloxacina/farmacocinética , Moxifloxacina/uso terapêutico , Suco Pancreático/metabolismo , Idoso , Área Sob a Curva , Feminino , Bactérias Gram-Negativas/efeitos dos fármacos , Humanos , Masculino , Testes de Sensibilidade Microbiana/métodos , Pessoa de Meia-Idade , Modelos Biológicos , Pâncreas/microbiologia , Suco Pancreático/microbiologia , Estudos Prospectivos
8.
J Antimicrob Chemother ; 62(3): 575-8, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18515790

RESUMO

OBJECTIVES: The aim of this study was to investigate the single- and multiple-dose pharmacokinetics (PK) of moxifloxacin and its penetration into ascitic fluid in patients with severe liver insufficiency (Child-Pugh class C). PATIENTS AND METHODS: In a single-centre, prospective, open-label study, nine adult cirrhosis patients were treated with 400 mg moxifloxacin infusion once a day. On days 1 and 3, drug concentrations in serum and ascites were determined before and at different time points up to 24 h after medication with a validated HPLC method. RESULTS: On day 1, serum concentrations of moxifloxacin decreased from a median of 3.7 mg/L at 1 h to 0.6 mg/L at 24 h. On day 3, serum peak and trough levels were only moderately increased in comparison with day 1, with moxifloxacin concentrations of 3.9 mg/L after 1 h and 0.6 mg/L 24 h after the third infusion. The AUC values were also slightly, but not statistically significantly, increased on day 3. Calculations of t(1/2), mean residence time, CL(tot) and V(ss) revealed no significant differences between days 1 and 3. Median concentrations of moxifloxacin in ascitic fluid were 1.4 mg/L (3 h after infusion) and 1.3 mg/L (6 h) on day 1 and 2.1 mg/L (3 h) and 1.9 mg/L (6 h) on day 3. Median ascites/serum ratios did not vary between days 1 and 3. CONCLUSIONS: PK parameters of moxifloxacin in patients with advanced liver cirrhosis differed only marginally from those from healthy control groups given in the literature. After multiple dosing, no drug accumulation was seen. Therefore, we conclude that a dose adjustment is not necessary in this patient group. Ascitic fluid reached bactericidal levels for common bacteria found in spontaneous bacterial peritonitis.


Assuntos
Compostos Aza/administração & dosagem , Compostos Aza/farmacocinética , Insuficiência Hepática , Quinolinas/administração & dosagem , Quinolinas/farmacocinética , Adulto , Idoso , Área Sob a Curva , Líquido Ascítico/química , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Fluoroquinolonas , Meia-Vida , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Moxifloxacina , Estudos Prospectivos , Soro/química , Fatores de Tempo
9.
Eur J Gastroenterol Hepatol ; 19(3): 257-63, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17301654

RESUMO

BACKGROUND: Human serum albumin has multiple functions, the most important being maintaining colloid osmotic pressure, ligand binding and transport. In liver failure, an impaired binding of endogenous substances and drugs can be observed. The aim of this study was to investigate the relationship between the severity of liver disease and an impaired albumin binding. METHODS: In 44 patients with decompensated liver cirrhosis, Child-Turcotte-Pugh and model for end-stage liver disease scores were assessed and the site II-specific albumin-binding function (albumin-binding capacity) was characterized. Briefly, the unbound amount of diazepam site ligand Dansylsarcosine in a sample was determined and compared with the unbound amount in a reference albumin solution (=100%). RESULTS: Thirty-two out of 44 of the patients presented with Child-Turcotte-Pugh class C, the median Child-Turcotte-Pugh score was 10 [6-13 (min-max)], median model for end-stage liver disease score was 21 (8-40) and the median albumin-binding capacity was 63 (24-91)% compared with healthy controls 98 (95-106)% (P<0.001). Albumin-binding capacity was found to be strongly correlated to model for end-stage liver disease (r=0.783; P<0.001). CONCLUSIONS: An impaired albumin-binding function of a site II-specific marker in decompensated liver cirrhosis was found to be correlated to the severity of the liver disease.


Assuntos
Cirrose Hepática/sangue , Albumina Sérica/metabolismo , Adulto , Idoso , Bilirrubina/sangue , Biomarcadores/sangue , Feminino , Humanos , Falência Hepática/sangue , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Prognóstico , Índice de Gravidade de Doença
10.
Med Klin (Munich) ; 102(8): 603-11, 2007 Aug 15.
Artigo em Alemão | MEDLINE | ID: mdl-17694280

RESUMO

BACKGROUND: Although the value of digitalis glycosides in the treatment of heart failure is limited, approximately 255 million DDDs of digitalis glycosides (DGs) were prescribed in Germany in 2004. METHOD: The authors analyzed data from adverse drug reactions (ADRs) resulting in hospitalization in the four German Pharmacovigilance Centers (PVCs) associated with DGs between 2000 and 2004. All patients with an at least "probable" ADR were included. RESULTS: Out of 3,092 ADR patients, in 314 patients (10.2%, 244 women) admission was caused by a DG-related ADR. Patients with DG-related ADR had a significantly lower body weight and were significantly older than patients with other ADRs. Per 1,000 patients exposed to DGs the incidence [95% CI] was calculated to 1.9 [1.0; 3.3] ADRs per 3 months exposition. Oral digitoxin was involved in 296 patients (228 women). 70.6% of women but only 29.3% of men were overdosed (> 1 mug/kg body weight per day). Women received significantly higher body weight-related digitoxin doses and had significantly higher digitoxin plasma levels than men. ADRs in patients with nonelevated digitoxin serum level were mainly caused by pharmacodynamic drug-drug interactions (e.g., beta-blockers). Overall, 42.4% of the ADRs were supposed to be preventable. CONCLUSION: Body weight-adapted dosing of digitoxin is essential for preventing DG-ADRs, particularly in elderly women with low body weight. Beyond giving attention to pharmacodynamic and pharmakokinetic drug-drug interactions, regular measurements of digitoxin plasma concentrations are crucial accounting for the increased half-life of digitoxin in the very old.


Assuntos
Arritmias Cardíacas/tratamento farmacológico , Cardiotônicos/toxicidade , Glicosídeos Digitálicos/toxicidade , Insuficiência Cardíaca/tratamento farmacológico , Admissão do Paciente/estatística & dados numéricos , Sistemas de Notificação de Reações Adversas a Medicamentos , Idoso , Idoso de 80 Anos ou mais , Arritmias Cardíacas/sangue , Arritmias Cardíacas/epidemiologia , Cardiotônicos/administração & dosagem , Cardiotônicos/farmacocinética , Glicosídeos Digitálicos/administração & dosagem , Glicosídeos Digitálicos/farmacocinética , Relação Dose-Resposta a Droga , Interações Medicamentosas , Monitoramento de Medicamentos , Feminino , Alemanha , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade
11.
Artigo em Inglês | MEDLINE | ID: mdl-16488198

RESUMO

Ertapenem is an important newer broad-spectrum carbapenem antibiotic covering various infections caused by common gram-positive and -negative aerobes and anaerobes. Due to its physicochemical peculiarities, pharmacokinetic data of other carbapenems are of limited value in predicting ertapenem distribution into particular compartments of the body. This raises demand for detailed pharmacokinetic studies and, as a consequence, rapid and specific ways of analysis. The HPLC assays for the quantification of ertapenem in biological matrices reported so far are based on columns of 4.6mm I.D. and involve pre-concentration by use of column-switching. However, automated column-switching technique is not standard equipment with all analytical laboratories. Furthermore, signal-to-noise ratios are likely not to be sufficient for quantification of specimens of low concentration. Therefore, a new HPLC/UV method based on narrow-bore column design using sample pre-cleaning by liquid-liquid extraction has been developed. The assay is rapid for specimen concentrations > or =1 mg/l and is easily tuned to achieve low quantification limits at high chromatographic resolution for lower concentrated samples. The method has been successfully applied to plasma, serum, lung tissue or cell homogenates, and broncho-alveolar lavage fluid with lower limits of quantification of 40 and 20 microg/l, respectively. It was also used for the pharmacokinetic monitoring of ertapenem in humans.


Assuntos
Líquido da Lavagem Broncoalveolar , Cromatografia Líquida de Alta Pressão/métodos , Pulmão/metabolismo , beta-Lactamas/metabolismo , Calibragem , Estudos de Casos e Controles , Ertapenem , Humanos , Sensibilidade e Especificidade , Espectrofotometria Ultravioleta , beta-Lactamas/sangue
12.
J Clin Pharmacol ; 45(6): 659-65, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15901747

RESUMO

Ertapenem is approved for the treatment of community-acquired pneumonia (CAP), but its in vivo penetration into lung tissue (LT), epithelial lining fluid (ELF), and alveolar cells (AC) is unknown. Fifteen patients undergoing thoracotomy were treated with 1 g intravenously for perioperative prophylaxis. Bronchoalveolar lavage was performed 1, 3, and 5 hours after ertapenem infusion. Normal LT was sampled at the time of lung extraction. Blood was collected before and at different time points up to 24 hours after infusion. Mean concentrations of ertapenem in plasma, ELF, and AC were at 1.0 hour, 63.1, 4.06, 0.004 mg/L; at 3.0 hours, 39.7, 2.59, 0.003 mg/L; and at 5.0 hours, 27.2, 2.83, 0.007 mg/L. Mean (range) concentration in LT was 7.60 (2.5-19.4) mg/kg tissue 1.5 to 4.5 hours after infusion. In plasma, ertapenem exhibited a Cmax of 94.7 +/- 23.3 mg/L and an AUC(0-last) of 501.1 +/- 266.3 mg x h/L. These results, combined with the reported (MIC)90 of most CAP bacteria, support the previously observed clinical efficacy of ertapenem in the treatment of CAP.


Assuntos
Alvéolos Pulmonares/efeitos dos fármacos , Toracotomia , beta-Lactamas/análise , beta-Lactamas/farmacologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/citologia , Infecções Comunitárias Adquiridas/tratamento farmacológico , Infecções Comunitárias Adquiridas/microbiologia , Esquema de Medicação , Ertapenem , Feminino , Meia-Vida , Humanos , Injeções Intravenosas , Masculino , Testes de Sensibilidade Microbiana/métodos , Pessoa de Meia-Idade , Alvéolos Pulmonares/química , Alvéolos Pulmonares/citologia , Mucosa Respiratória/química , Mucosa Respiratória/efeitos dos fármacos , beta-Lactamas/farmacocinética
13.
Clin Pharmacol Ther ; 75(6): 546-57, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15179409

RESUMO

BACKGROUND AND OBJECTIVE: St John's wort preparations vary in composition, main constituents, formulation, and daily dose administered. The aim of the study was to evaluate the possible pharmacokinetic interaction of marketed St John's wort formulations and doses with digoxin. METHODS: A randomized, placebo-controlled, parallel-group study was performed in 96 healthy volunteers in 3 study parts. A 7-day loading phase with digoxin was followed by 14 days of comedication with placebo or one of 10 St John's wort products varying in dose and formulation. The pharmacokinetics of digoxin was determined before comedication and on day 14 of comedication. RESULTS: Comedication comprised traditionally used Hypericum products; 2 g powder without hyperforin, tea, juice, oil extract, and placebo had no significant interaction with digoxin nor did hyperforin-free extract (Ze 117) or low daily doses of hyperforin-containing Hypericum powder (1 g, 0.5 g). However, comedication with the high-dose hyperforin-rich extract LI 160 resulted in a reduction of digoxin area under the curve from time 0 to 24 hours (AUC(0-24)) of -24.8% (95% confidence interval [CI], -28.3 to -21.3), a reduction in digoxin maximal plasma concentration (C(max)) of -37% (95% CI, -42 to -32), and a reduction in digoxin plasma concentration at 24 hours after previous dosing (C(trough)) of -19% (95% CI, -27 to -11). Comedication with 4 g Hypericum powder with comparable hyperforin content resulted in a reduction in digoxin AUC(0-24) of -26.6% (95% CI, -37.3 to -15.9), a reduction in digoxin C(max) of -38% (95% CI, -48 to -18), and a reduction in digoxin C(trough) of -19% (95% CI, -27 to -10). Two grams of Hypericum powder with half the hyperforin content resulted in a less prominent reduction in AUC(0-24) of -17.7% (95% CI, -21.6 to -13.7), C(max) (-21%; 95% CI, -40 to -2), and C(trough) (-13%; 95% CI, -21 to -5). CONCLUSIONS: The interaction of St John's wort and digoxin varies within St John's wort preparations and doses and seems to be correlated with the dose, particularly of hyperforin.


Assuntos
Digoxina/farmacocinética , Hypericum/metabolismo , Adolescente , Adulto , Área Sob a Curva , Química Farmacêutica , Intervalos de Confiança , Método Duplo-Cego , Interações Medicamentosas , Feminino , Humanos , Masculino , Extratos Vegetais/administração & dosagem , Extratos Vegetais/farmacocinética , Pós , Comprimidos com Revestimento Entérico , Chá/metabolismo
14.
Drug Saf ; 37(4): 225-35, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24550104

RESUMO

BACKGROUND: Self-medication, including both the use of over-the-counter (OTC) drugs and the use of formerly prescribed drugs taken without a current physician's recommendation, is a public health concern; however, little data exist regarding the actual risk. OBJECTIVE: We aimed to analyse self-medication-related adverse drug reactions (ADRs) leading to hospitalisation. METHODS: In a multi-centre, observational study covering a hospital catchment area of approximately 500,000 inhabitants, we analysed self-medication-related ADRs leading to hospital admissions in internal medicine departments. Data of patients with ADRs were comprehensively documented, and ADR causality was assessed using Bégaud's algorithm. The included ADRs occurred between January 2000 and December 2008 and were assessed to be at least 'possibly' drug related. RESULTS: Of 6,887 patients with ADRs, self-medication was involved in 266 (3.9 %) patients. In 143 (53.8 %) of these patients, ADRs were due to OTC drugs. Formerly prescribed drugs and potential OTC drugs accounted for the remaining ADRs. Most self-medication-related ADRs occurred in women aged 70-79 years and in men aged 60-69 years. Self-medication-related ADRs were predominantly gastrointestinal complaints caused by non-steroidal anti-inflammatory drugs (most frequently OTC acetylsalicylic acid [ASA, aspirin]). In 102 (38.3 %) of the patients with self-medication-related ADRs, a relevant drug-drug interaction (DDI), occurring between a self-medication and a prescribed medication, was present (most frequently ASA taken as an OTC drug and prescribed diclofenac). CONCLUSION: In the general population, self-medication plays a limited role in ADRs leading to hospitalisation. However, prevention strategies focused on elderly patients and patients receiving interacting prescribed drugs would improve patient safety.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Medicamentos sem Prescrição/efeitos adversos , Medicamentos sob Prescrição/efeitos adversos , Automedicação/efeitos adversos , Sistemas de Notificação de Reações Adversas a Medicamentos , Idoso , Interações Medicamentosas/fisiologia , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Segurança do Paciente , Estudos Prospectivos
15.
Implement Sci ; 9: 151, 2014 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-25287853

RESUMO

BACKGROUND: Treatment of patients with multimorbidity is challenging. A rational reduction of long-term drugs can lead to decreased mortality, less acute hospital treatment, and a reduction of costs. Simplification of drug treatment schemes is also related to higher levels of patient satisfaction and adherence. The POLITE-RCT trial will test the effectiveness of an intervention aiming at reducing the number of prescribed long-term drugs among multimorbid and chronically ill patients. The intervention focuses on the interface between primary and secondary health care and includes a pharmacist-based, patient-centered medication review prior to the patient's discharge from hospital. METHODS: The POLITE-RCT trial is a cluster randomized controlled trial. Two major secondary health care providers of Mecklenburg-Western Pomerania, Germany, take part in the study. Clusters are wards of both medical centers. All wards where patients with chronic diseases and multimorbidity are regularly treated will be included. Patients aged 65+ years who take five or more prescribed long-term drugs and who are likely to spend at least 5 days in the participating hospitals will be recruited and included consecutively. Cluster-randomization takes place after a six-month baseline data collection period. Patients of the control group receive care as usual. The independent two main primary outcomes are (1) health-related quality of life (EQ-5D) and (2) the difference in the number of prescribed long-term pharmaceutical agents between intervention and control group. The secondary outcomes are appropriateness of prescribed medication (PRISCUS list, Beers Criteria, MAI), patient satisfaction (TSQM), patient empowerment (PEF-FB-9), patient autonomy (IADL), falls, re-hospitalization, and death. The points of measurement are at admission to (T0) and discharge from hospital (T1) as well as 6 and 12 months after discharge from the hospital (T2 and T3). In 42 wards, 1,626 patients will be recruited. DISCUSSION: In case of positive evaluation, the proposed study will provide evidence for a sustainable reduction of polypharmacy by enhancing patient-centeredness and patient autonomy. TRIAL REGISTRATION: Current Controlled Trials ISRCTN42003273.


Assuntos
Doença Crônica/tratamento farmacológico , Polimedicação , Medicamentos sob Prescrição/uso terapêutico , Idoso , Análise por Conglomerados , Alemanha , Hospitalização/estatística & dados numéricos , Humanos , Assistência de Longa Duração , Satisfação do Paciente
16.
Dtsch Arztebl Int ; 110(14): 244-52, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23616817

RESUMO

BACKGROUND: Even after the recent approval of newer oral anticoagulants for clinical use, the vitamin K antagonist phenprocoumon remains an important treatment option for many patients. In order to quantify the hitherto "accepted" risks of phenprocoumon treatment, we analyzed adverse drug reactions (ADRs) that led to hospitalization on the internal medicine wards of four German pharmacovigilance centers. METHODS: We prospectively analyzed ADRs leading to hospitalization on the internal medicine wards of the hospitals belonging to the German Network of Regional Pharmacovigilance Centers (Rostock, Greifswald, Jena, and the Sophien- und Hufeland-Klinikum in Weimar) in the years 2000 to 2008. RESULTS: The 851 patients hospitalized for a phenprocoumon-associated ADR accounted for 12.4% of the 6887 ADR-related hospitalizations in the period of the study. 723 (85%) were admitted for a hemorrhage, usually in the gastrointestinal tract (482 patients); 8 patients died as a consequence of hemorrhage associated with phenprocoumon exposure. Using drug utilization data for the catchment areas of the participating hospitals, we calculate a rate of 5 to 7 hemorrhages leading to hospitalization in an internal medicine ward per 1000 patient-years under phenprocoumon treatment. One-third of the patients who had a hemorrhage were taking other interacting drugs, mainly inhibitors of platelet aggregation and non-steroidal anti-inflammatory drugs. Among the patients who were taking phenprocoumon because of a history of thromboembolic events or for atrial fibrillation, 60% to 70% of those who had hemorrhages had an international normalized ratio (INR) that was above the upper limit of the therapeutic range. Phenprocoumon-associated impairment of liver function arose in 23 patients (2.7%). CONCLUSION: In this study, about one-eighth of all ADR-related admissions to hospital internal medicine wards were associated with phenprocoumon. There is a need for a comparative risk-benefit assessment of phenprocoumon and the newer oral anticoagulants under real-life conditions.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/epidemiologia , Hemorragia/epidemiologia , Hospitalização/estatística & dados numéricos , Medicina Interna/estatística & dados numéricos , Femprocumona/uso terapêutico , Tromboembolia/epidemiologia , Tromboembolia/prevenção & controle , Idoso , Anticoagulantes/uso terapêutico , Comorbidade , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Farmacovigilância , Prevalência , Estudos Prospectivos , Medição de Risco
18.
Arzneimittelforschung ; 60(8): 483-91, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20863004

RESUMO

A randomized, double-blind, 2-way crossover trial of 24 healthy volunteers investigated the influence of esomeprazole (CAS 119141-88-7) and pantoprazole (CAS 102625-70-7), both 1 x 40 mg orally for 11 days, on the pharmacokinetics and pharmacodynamics of diazepam (CAS 439-14-5). Single-dose intravenous diazepam 0.1 mg/kg was administered on day 6. Blood sampling for pharmacokinetic assessment was conducted 0-120 h post diazepam application and data were analyzed using a model-independent approach and ANOVA. Pharmacodynamic parameters were assessed by an oculodynamic test and auditory evoked potentials 0-10 h post diazepam application. Data were analyzed using a linear mixed regression model. The AUC of diazepam was increased by 28.0%, Cmax by 31.4% and t1/2 by 41.1% in the esomeprazole vs. pantoprazole group. Myogenic parameters such as angular velocity of saccadic eye movements and complex choice reaction time were impaired with esomeprazole when compared to pantoprazole after diazepam administration (P < 0.0028) at 4-6 h. The sedation parameter microsleep doubled (2.6 vs. 1.1%; P < 0.0073). No differences in auditory evoked potentials were observed. In conclusion, it cannot be ruled out that a relevant pharmacodynamic interaction between diazepam and esomeprazole may occur when both drugs are concomitantly administered. Pantoprazole may provide a higher safety profile.


Assuntos
2-Piridinilmetilsulfinilbenzimidazóis/farmacologia , Cognição/efeitos dos fármacos , Diazepam/farmacologia , Diazepam/farmacocinética , Esomeprazol/farmacologia , Hipnóticos e Sedativos/farmacologia , Hipnóticos e Sedativos/farmacocinética , Inibidores da Bomba de Prótons/farmacologia , Desempenho Psicomotor/efeitos dos fármacos , 2-Piridinilmetilsulfinilbenzimidazóis/efeitos adversos , Adolescente , Adulto , Nível de Alerta/efeitos dos fármacos , Estudos Cross-Over , Diazepam/administração & dosagem , Relação Dose-Resposta a Droga , Método Duplo-Cego , Interações Medicamentosas , Eletroculografia , Esomeprazol/efeitos adversos , Feminino , Humanos , Hipnóticos e Sedativos/administração & dosagem , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Pantoprazol , Estimulação Luminosa , Inibidores da Bomba de Prótons/efeitos adversos , Movimentos Sacádicos/efeitos dos fármacos , Adulto Jovem
19.
J Antimicrob Chemother ; 59(2): 277-84, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17185298

RESUMO

OBJECTIVES: Most information about pharmacokinetics of antimicrobial agents is obtained from studies in healthy volunteers. However, antibiotics are therapeutically used in infected patients with very different pharmacokinetic properties compared with healthy individuals. PATIENTS AND METHODS: In a single-centre, prospective, open-label study, 17 adult critically ill patients with early-onset ventilator-associated pneumonia (VAP) were treated with 1 g of ertapenem infusion once a day. Blood and urine samples were collected before and at different time-points up to 24 h after medication on day 1. Concentrations of ertapenem in plasma were determined with a validated HPLC method. Free-drug concentrations were estimated using a two-class binding site equation. RESULTS: The overall clinical success rate of the assessable cases was 66.7% (12/16). Pharmacokinetic parameters of ertapenem in our critically ill patients were clearly different when compared to those reported in the literature for healthy volunteers. The enhanced V(z) (17 vs. 8 L) and CL(TOT) (43 vs. 20 mL/min) with resulting lower C(max) (90 vs. 253 mg/L) and AUC(0-infinity) (418 vs. 817 mg x h/L) values were mainly related to hypoalbuminaemia (range 9.2-25.6 g/L) in our patient population. A population pharmacokinetic analysis using the NONMEM program indicated creatinine clearance as a significant covariate for explaining the between-subject variability of ertapenem in the patient population. Estimated free plasma concentrations of ertapenem exceeded a MIC(90) of 2 mg/L only for 6 h (25%) after infusion. CONCLUSIONS: For an adequate dose adjustment of highly protein-bound drugs like ertapenem, knowledge of actual albumin concentrations is necessary. A shortening of the dosage interval or continuous infusion of ertapenem should be considered to ensure optimal free concentrations in critically ill patients with severe hypoalbuminaemia and normal renal function.


Assuntos
Antibacterianos , Pneumonia Associada à Ventilação Mecânica/tratamento farmacológico , beta-Lactamas , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/sangue , Antibacterianos/uso terapêutico , Antibacterianos/urina , Cromatografia Líquida de Alta Pressão , Creatinina/urina , Estado Terminal , Ertapenem , Feminino , Humanos , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Pneumonia Associada à Ventilação Mecânica/sangue , Pneumonia Associada à Ventilação Mecânica/urina , Estudos Prospectivos , Resultado do Tratamento , beta-Lactamas/sangue , beta-Lactamas/uso terapêutico , beta-Lactamas/urina
20.
Eur J Clin Pharmacol ; 62(3): 225-33, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16477470

RESUMO

Recently, interactions of herbal medicines with synthetic drugs came into focus of particular interest. In the past 3 years, more than 50 papers were published regarding interactions between St. John's wort (Hypericum perforatum L.; SJW) and prescription drugs. Co-medication with SJW resulted in decreased plasma concentrations of a number of drugs including amitriptyline, cyclosporine, digoxin, indinavir, irinotecan, warfarin, phenprocoumon, alprazolam, dextrometorphane, simvastatin, and oral contraceptives. Sufficient evidence from interaction studies and case reports indicate that SJW is a potent inducer of cytochrome P450 enzymes (particularly CYP3A4) and/or P-glycoprotein. Recent studies could show that the degree of enzyme induction by SJW correlates strongly with the amount of hyperforin found in the product. Products that do not contain substantial amounts of hyperforin (<1%) have not been shown to produce clinically relevant enzyme induction. On the other hand, some evidence suggests that hyperforin may also contribute to the antidepressant activity of SJW. However, clinical studies using SJW preparations with a low hyperforin amount (<1%) clearly demonstrated the superiority of this plant extract over placebo and its equivalence to imipramine and fluoxetine in the treatment of mild to moderate forms of depression. In the present paper clinical significant SJW interactions are critically evaluated against the background of hyperforin.


Assuntos
Interações Ervas-Drogas , Hypericum/química , Preparações Farmacêuticas/administração & dosagem , Floroglucinol/análogos & derivados , Terpenos/administração & dosagem , Compostos Bicíclicos com Pontes/administração & dosagem , Compostos Bicíclicos com Pontes/química , Compostos Bicíclicos com Pontes/metabolismo , Citocromo P-450 CYP3A , Sistema Enzimático do Citocromo P-450/metabolismo , Humanos , Preparações Farmacêuticas/química , Preparações Farmacêuticas/metabolismo , Floroglucinol/administração & dosagem , Floroglucinol/química , Floroglucinol/metabolismo , Plantas Medicinais/química , Terpenos/química , Terpenos/metabolismo
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