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1.
Ther Drug Monit ; 44(4): 558-567, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35482468

RESUMO

BACKGROUND: Poor statin adherence remains a public health concern associated with adverse outcomes. We evaluated the use of pharmacokinetic measurements to monitor adherence to simvastatin in patients with coronary heart disease (CHD). METHODS: Eighteen patients with CHD taking an evening dose of simvastatin 20 mg (n = 7), 40 mg (n = 5), or 80 mg (n = 6) were examined at steady-state pharmacokinetics. Ten patients were instructed to interrupt simvastatin dosing and return for blood sampling for the subsequent 3 days. Dose-normalized plasma concentrations of simvastatin lactone and simvastatin acid and the sum of the 2 were evaluated to discriminate between adherent dosing and dose omission. Bioanalytical quantification was performed using liquid chromatography-tandem mass spectrometry. RESULTS: A simvastatin acid cutoff of 1.0 × 10 -2 nmol -1 ·L -1 ·mg -1 identified 100% of those omitting 2 doses and 60% of those omitting a single dose. Simvastatin acid showed superior ability to discriminate dose omission, as well as the best agreement between samples handled at ambient and cool temperatures (median deviation 3.5%; interquartile range -2.5% to 13%). The cutoff for a morning dose schedule, with a similar ability to discriminate, was estimated at 2.0 × 10 -3 nmol -1 ·L -1 ·mg -1 . CONCLUSIONS: The present method discriminated between adherence and reduced adherence to simvastatin therapy in patients with CHD. Sample handling is feasible for routine practice, and the assessment of adherence can be performed by direct measurement of simvastatin acid in a blood sample, according to defined cutoff values. Further studies validating the cutoff value and utility for clinical application are encouraged.


Assuntos
Anticolesterolemiantes , Doença das Coronárias , Cromatografia Líquida , Doença das Coronárias/induzido quimicamente , Doença das Coronárias/tratamento farmacológico , Humanos , Plasma , Sinvastatina/efeitos adversos , Sinvastatina/uso terapêutico
2.
Ther Drug Monit ; 43(2): 247-255, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33181621

RESUMO

BACKGROUND: Prednisolone (PL) is a standard component of most immunosuppressive protocols after solid organ transplantation (Tx). Adverse effects are frequent and well known. The aim of this study was to characterize the pharmacokinetics (PKs) of PL and prednisone (PN), including cortisol (CL) and cortisone (CN) profiles, after PL treatment in renal Tx recipients in the early post-Tx phase. METHODS: This single-center, prospective, observational study included stable renal Tx recipients, >18 years of age, and in the early postengraftment phase. Blood samples were obtained predose and during a 24-hour dose interval [n = 26 samples per area under the curve (AUC0-24)], within the first 8 weeks post-Tx. PL, PN, CL, and CN concentrations were measured using high-performance liquid chromatography-tandem mass spectrometry. RESULTS: In renal Tx recipients (n = 28), our results indicated a relatively high PL exposure [median, range AUC0-24 = 3821 (2232-5382) mcg h/L], paralleled by strong suppression of endogenous CL profile, demonstrated by a low CL evening-to-morning ratio [median, range 11 (3-47)%]. A negative correlation (r = -0.83) between PL AUC0-24 and morning CL levels was observed. The best single PK variable to predict PL AUC0-24 was PL C6 (r2 = 0.82). An algorithm based on 3 PK sampling time points: trough, 2, and 4 hours after PL dosing, predicted PL AUC0-24 with a low percentage prediction error (PPE = 5.2 ± 1.5%) and a good correlation of determination (r2 = 0.91). PL AUC0-24 varied 3-fold among study participants, whereas CL AUC0-24 varied by 18-fold. CONCLUSIONS: The large interindividual variability in both PL exposure and suppression of endogenous CL implies a possible role for therapeutic drug monitoring. An abbreviated profile within the first 4 hours after PL dosing provides a good prediction of PL exposure in renal Tx recipients. The strong negative correlation between PL AUC0-24 and morning CL levels suggests a possible surrogate marker for drug exposure for further evaluation.


Assuntos
Transplante de Rim , Prednisolona/farmacocinética , Prednisona/farmacocinética , Adulto , Área Sob a Curva , Humanos , Estudos Prospectivos
3.
Ther Drug Monit ; 41(1): 19-28, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30633723

RESUMO

BACKGROUND: Low adherence to statin therapy remains a public health concern associated with poor prognosis in cardiovascular disease patients. A feasible method for statin adherence monitoring in clinical practice has yet to be developed. In this article, we describe a novel method designed for the direct monitoring of atorvastatin adherence based on the sum of parent drug and major metabolites in blood samples. METHODS: Acid and lactone forms of atorvastatin, 2-OH-atorvastatin, and 4-OH-atorvastatin were assayed. Plasma proteins were precipitated with an acidified mixture of methanol, acetonitrile, and aqueous zinc sulfate, and the supernatant was analyzed with 2-channel reversed-phase chromatography coupled to tandem mass spectrometry. Assay validation was performed according to the guidelines provided by the European Medicines Agency and the US Food and Drug Administration. RESULTS: The effective run time was 1 minute and 45 seconds per sample. Mean accuracy ranged from 92% to 110%, and coefficients of variation were ≤8.1% over the measurement ranges for individual compounds. The sum of acids and corresponding lactones was stable in clinical plasma samples kept at ambient temperature for up to 6 days after blood sampling (mean sum within 96.6%-101% of baseline). CONCLUSIONS: A fast and reliable assay for the quantification of atorvastatin and its 5 major metabolites in clinical blood samples is reported. Limitations of preanalytical stability were solved using the sum of the acid and lactone forms. The assay is feasible for implementation in clinical practice, and the sum of parent drug and metabolites may be used for direct monitoring of atorvastatin adherence.


Assuntos
Atorvastatina/sangue , Atorvastatina/metabolismo , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/prevenção & controle , Cromatografia Líquida de Alta Pressão/métodos , Monitoramento de Medicamentos/métodos , Espectrometria de Massas em Tandem/métodos , Anticolesterolemiantes/sangue , Anticolesterolemiantes/metabolismo , Coleta de Amostras Sanguíneas/métodos , Doenças Cardiovasculares/metabolismo , Humanos , Projetos Piloto , Reprodutibilidade dos Testes
4.
Ther Drug Monit ; 41(5): 607-614, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31584926

RESUMO

BACKGROUND: Therapeutic drug monitoring is standard practice for the immunosuppressant tacrolimus (Tac). Venous blood sampling at outpatient clinics is time-consuming and impractical with regard to obtaining trough concentrations on clinical visit days. Home-based blood sampling may be patient friendly and pave the way for limited sampling strategies for the prediction of total drug exposure. The aim was to establish a Tac assay for dried capillary microsamples, ensuring reliable measurements during the full dose interval in renal transplant recipients. METHODS: An assay based on volumetric absorptive microsampling and liquid chromatography tandem mass spectrometry was validated. The agreement between capillary microsamples and liquid venous samples was investigated in stable renal recipients on twice-daily Tac dosing. Sampling throughout the 12-hour dose interval was examined at 2 separate days, at least 1 week apart, for each participant. Two sets of samples were obtained at each time point, one delivered directly to the laboratory and one sent through mail. RESULTS: Twenty-seven renal transplant recipients were included, of whom 26 were investigated twice. Tac was efficiently extracted from the dried microsamples (mean recovery 94%-103%). The between-series mean accuracy was 88%-98% with coefficients of variation ≤5.0% (≤11% at the lower limit of quantification), measurement range 0.70-60 mcg/L. The mean difference between parallel microsamples was 5%-7%. Overall, the mean differences between dried microsamples and liquid samples were -3.1% when mailed (n = 679) and -4.2% when directly delivered (n = 682). Less than 8% were outside ±20%. The microsamples were stable for 1 month at ambient temperature. CONCLUSIONS: The microsample method demonstrated acceptable performance. Tac concentrations can be reliably quantified throughout the dose interval by using volumetric absorptive microsampling in renal transplant recipients, and the results are not influenced by postal shipment.


Assuntos
Imunossupressores/sangue , Tacrolimo/sangue , Adulto , Idoso , Coleta de Amostras Sanguíneas/métodos , Cromatografia Líquida/métodos , Monitoramento de Medicamentos/métodos , Feminino , Humanos , Rim/efeitos dos fármacos , Transplante de Rim/métodos , Limite de Detecção , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Espectrometria de Massas em Tandem/métodos , Transplantados , Adulto Jovem
5.
Ther Drug Monit ; 40(3): 292-300, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29578937

RESUMO

BACKGROUND: Tacrolimus (TAC) is currently the cornerstone of immunosuppressive protocols for renal transplant recipients. Despite therapeutic whole blood monitoring, TAC is associated with nephrotoxicity, and it has been hypothesized that intrarenal accumulation of TAC and/or its metabolites are involved. As TAC is a substrate of P-glycoprotein (P-gp), the expression and activity of this efflux transporter could influence the levels of TAC in renal tissue. The primary aim of this study was to develop and validate a method for quantification of TAC in tissue homogenates from single human renal core biopsies. The secondary aim was to provide measures of P-gp expression and of the demethylated metabolites of TAC in the same renal biopsy. METHODS: Human renal tissue, with and without clinical TAC exposure, was used for method development and validation. Homogenates were prepared with bead-beating, and concentrations of TAC and its demethylated metabolites were analyzed with liquid chromatography tandem mass spectrometry after protein precipitation. A Western blot method was used for semiquantification of P-gp expression in the homogenates. The final methods were applied to renal core biopsies from 2 transplant patients. RESULTS: The TAC assay showed within- and between-run mean accuracy between 99.7% and 107% and coefficients of variation ≤6.7%. Matrix effects were nonsignificant, and samples were stable for 3 months preanalytically when stored at -80°C. TAC concentrations in the renal core biopsies were 62.6 and 43.7 pg/mg tissue. The methods for measurement of desmethyl-TAC and P-gp expression were suitable for semiquantification in homogenates from renal core biopsies. CONCLUSIONS: These methods may be valuable for the elucidation of the pharmacokinetic mechanisms behind TAC-induced nephrotoxicity in renal transplant recipients.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Monitoramento de Medicamentos/métodos , Imunossupressores/análise , Rim/patologia , Tacrolimo/análise , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Biópsia , Expressão Gênica , Humanos , Rim/efeitos dos fármacos , Rim/metabolismo , Transplante de Rim/métodos , Espectrometria de Massas em Tandem/métodos
6.
BMC Pediatr ; 15: 117, 2015 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-26357864

RESUMO

BACKGROUND: Chronic Fatigue Syndrome (CFS) is a common and disabling condition in adolescence with few treatment options. A central feature of CFS is orthostatic intolerance and abnormal autonomic cardiovascular control characterized by sympathetic predominance. We hypothesized that symptoms as well as the underlying pathophysiology might improve by treatment with the alpha2A-adrenoceptor agonist clonidine. METHODS: A total of 176 adolescent CFS patients (12-18 years) were assessed for eligibility at a single referral center recruiting nation-wide. Patients were randomized 1:1 by a computer system and started treatment with clonidine capsules (25 µg or 50 µg twice daily, respectively, for body weight below/above 35 kg) or placebo capsules for 9 weeks. Double-blinding was provided. Data were collected from March 2010 until October 2012 as part of The Norwegian Study of Chronic Fatigue Syndrome in Adolescents: Pathophysiology and Intervention Trial (NorCAPITAL). Effect of clonidine intervention was assessed by general linear models in intention-to-treat analyses, including baseline values as covariates in the model. RESULTS: A total of 120 patients (clonidine group n = 60, placebo group n = 60) were enrolled and started treatment. There were 14 drop-outs (5 in the clonidine group, 9 in the placebo group) during the intervention period. At 8 weeks, the clonidine group had lower plasma norepinephrine (difference = 205 pmol/L, p = 0.05) and urine norepinephrine/creatinine ratio (difference = 3.9 nmol/mmol, p = 0.002). During supine rest, the clonidine group had higher heart rate variability in the low-frequency range (LF-HRV, absolute units) (ratio = 1.4, p = 0.007) as well as higher standard deviation of all RR-intervals (SDNN) (difference = 12.0 ms, p = 0.05); during 20° head-up tilt there were no statistical differences in any cardiovascular variable. Symptoms of orthostatic intolerance did not change during the intervention period. CONCLUSIONS: Low-dose clonidine reduces catecholamine levels in adolescent CFS, but the effects on autonomic cardiovascular control are sparse. Clonidine does not improve symptoms of orthostatic intolerance. TRIAL REGISTRATION: Clinical Trials ID: NCT01040429, date of registration 12/28/2009.


Assuntos
Agonistas de Receptores Adrenérgicos alfa 2/administração & dosagem , Clonidina/administração & dosagem , Síndrome de Fadiga Crônica/tratamento farmacológico , Síndrome de Fadiga Crônica/fisiopatologia , Adolescente , Agonistas de Receptores Adrenérgicos alfa 2/sangue , Clonidina/sangue , Creatinina/urina , Método Duplo-Cego , Epinefrina/sangue , Epinefrina/urina , Frequência Cardíaca/efeitos dos fármacos , Humanos , Norepinefrina/sangue , Norepinefrina/urina , Intolerância Ortostática/tratamento farmacológico , Intolerância Ortostática/fisiopatologia , Teste da Mesa Inclinada
7.
Ther Drug Monit ; 36(1): 108-18, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24061448

RESUMO

BACKGROUND: The development of biomarkers describing the individual responses to the immunosuppressant mycophenolic acid (MPA) has focused on the target enzyme activity [inosine 5'-monophosphate dehydrogenase (IMPDH)]. An extended strategy is to quantify the metabolic consequences of IMPDH inhibition. The aim of this study was to develop an assay for quantification of IMPDH activity and related purine bases and to provide preliminary data on the behavior of these biomarkers during clinical exposure to MPA. METHODS: Liquid chromatography-mass spectrometry was used to determine xanthine (IMPDH activity in incubated cell lysate), hypoxanthine, guanine, and adenine derived from free nucleotides in lymphocytes. Analytical performance was assessed, and the biomarkers were examined in CD4⁺ cells from 2 groups: Healthy individuals in a single-dose MPA study (n = 5) and liver transplant recipients on MPA therapy (n = 15). RESULTS: Coefficients of variation between series were below 10% and 15% for measurement of the purines and IMPDH activity, respectively. Although IMPDH was inhibited, the purine levels increased in response to MPA in 3 of the 5 healthy individuals, and this positive response seemed to be associated with IMPDH1 c.579 + 119 G/G and c.580 - 106 G/G. In the liver transplant study, guanine was not reduced in response to the transient drop in IMPDH activity after MPA dosing. However, there were trends toward decrease in guanine and elevation of hypoxanthine during prolonged MPA therapy. The guanine/hypoxanthine ratio (median) was 37% lower and the adenine level was 21% lower at day 17 compared with day 4 after transplantation. CONCLUSIONS: The assay allows precise quantification of IMPDH activity, hypoxanthine, guanine, and adenine in lymphocytes. Some individuals may possess a counteracting purine response to the MPA-mediated inhibition of IMPDH. Reduction of the guanine/hypoxanthine ratio may be related to prolonged inhibition of IMPDH and seems as an intriguing pharmacodynamic biomarker for MPA.


Assuntos
IMP Desidrogenase/metabolismo , Imunossupressores/farmacologia , Transplante de Fígado , Ácido Micofenólico/análogos & derivados , Adulto , Idoso , Biomarcadores/metabolismo , Cromatografia Líquida/métodos , Estudos Cross-Over , Feminino , Humanos , Imunossupressores/administração & dosagem , Linfócitos/metabolismo , Masculino , Pessoa de Meia-Idade , Ácido Micofenólico/administração & dosagem , Ácido Micofenólico/farmacologia , Purinas/metabolismo , Espectrometria de Massas em Tandem/métodos , Fatores de Tempo , Adulto Jovem
8.
Atheroscler Plus ; 55: 31-38, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38293288

RESUMO

Background and aims: Statin-associated muscle symptoms (SAMS) is a prevalent cause of statin discontinuation. It is challenging and time-consuming for clinicians to assess whether symptoms are caused by the statin or not, and diagnostic biomarkers are requested. Atorvastatin metabolites have been associated with SAMS. We aimed to compare atorvastatin pharmacokinetics between coronary heart disease (CHD) patients with and without clinically statin intolerance and statin-dependent histopathological alterations in muscle tissue. Secondarily we aimed to assess genetic variants relevant for the observed pharmacokinetic variables. Methods: Twenty-eight patients with CHD and subjective SAMS were included in the exploratory MUSE biomarker study in 2020. Participants received atorvastatin 40 mg/day for seven weeks followed by no statins for eight weeks. Muscle biopsies and blood were collected at the end of each period. Four patients were categorized as clinically intolerant to ≥3 statins prior to study start whereas four patients had signs of muscle cell damage during treatment. Results: We found significantly lower levels of atorvastatin acids, and higher lactone/acid ratios in the statin intolerant, both in muscle and plasma. With optimal cut-off, the combination of 2-OH-atorvastatin acid and the 2-OH-atorvastatin lactone/acid ratio provided sensitivity, specificity, and predictive values of 100 %. Patients with variants in UGT1A1 and UGT1A3 had higher lactone metabolite levels than those with wild type, both in muscle and plasma. Conclusion: Atorvastatin metabolites appear promising as biomarkers for the identification of clinical statin intolerance in patients with self-perceived SAMS, but the findings have to be confirmed in larger studies.

9.
Scand J Clin Lab Invest ; 73(2): 117-24, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23281843

RESUMO

BACKGROUND: The pharmacokinetics of the immunosuppressant mycophenolic acid (MPA) demonstrates high inter- and intra-patient variability. Variation in the binding of MPA to albumin has been postulated to be an important factor in this variability, and monitoring of free MPA has been suggested to improve therapeutic drug monitoring (TDM) of MPA. Inosine monophosphate dehydrogenase (IMPDH) is the target enzyme for MPA, therefore the IMPDH activity in lymphocytes can serve as a marker of the MPA-specific response. This study aimed to explore how the albumin concentration influences the free concentration of MPA in liver transplant recipients and to assess whether alteration in the free MPA influences IMPDH activity in CD4 + cells. METHODS: Blood samples were taken from 20 liver transplant recipients on two separate occasions (days 3-5 and 16-21). Total and free concentrations of MPA, and IMPDH activity were measured during the first 4 h of each dose interval. RESULTS: Albumin levels correlated with the free fraction of MPA. However, the total MPA and free MPA were equal predictors of the immunosuppressive response as defined by IMPDH activity. CONCLUSION: Total and free MPA are equally good predictors of the immunosuppressive effect exerted by MPA as defined by IMPDH activity. IMPDH activity measurements represent a promising approach to TDM in patients treated with MPA.


Assuntos
IMP Desidrogenase/metabolismo , Imunossupressores/farmacocinética , Transplante de Fígado/imunologia , Ácido Micofenólico/análogos & derivados , Adulto , Idoso , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/enzimologia , Feminino , Rejeição de Enxerto/prevenção & controle , Humanos , Imunossupressores/uso terapêutico , Hepatopatias/cirurgia , Masculino , Pessoa de Meia-Idade , Ácido Micofenólico/farmacocinética , Ácido Micofenólico/uso terapêutico , Adulto Jovem
10.
Scand J Clin Lab Invest ; 73(6): 485-93, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23819644

RESUMO

OBJECTIVE: Neutrophil elastase (NE) concentration is associated with progression of acute pancreatitis (AP), but measuring total NE concentration includes biologically inactive NE. This study aims to investigate the relationship between NE activity and the aetiology and severity of AP and associated organ failure. METHODS: Seventy-five patients admitted to our surgery department with a first episode of AP during 2004-2005 were age- and sex-matched to 20 healthy volunteers (controls). NE activity was assessed using venous blood samples obtained on patient admission and after 1, 2 and 14 days. One sample was also taken from each control. ANOVA was used for statistical comparison between groups. RESULTS: Baseline NE activity (geometric mean; 95% confidence intervals) differed between patients (58.6 nM of substrate 7-amino-4-methylcoumarin [AMC]/hour; 48.52-70.72) and controls (31.5 nM AMC/hour; 25.5-39.0) (p = 0.0003), and did not correlate with time between symptom onset and admission. Patients with alcohol-induced AP demonstrated higher mean activity (59.1 nM AMC/h; 44.7-78.2) than those with gallstone-induced AP (41.7 nM AMC/h; 33.9-51.4) (p = 0.0496). NE activity was higher overall in patients with predicted severe AP (60.9 nM AMC/h; 48.0-77.2) than in those with predicted mild AP (42.1 nM AMC/h; 34.9-50.8) (p = 0.027). Patients with respiratory failure had higher NE activity (82.5 nM AMC/h; 57.5-118.4) than those without (43.9 nM AMC/h; 37.6-51.3) (p = 0.0024). CONCLUSIONS: NE activity was associated with predicted severity of AP and AP-associated respiratory failure. Specific NE inhibitors may have therapeutic potential in acute pancreatitis.


Assuntos
Elastase de Leucócito/metabolismo , Pancreatite Necrosante Aguda/enzimologia , Pancreatite Alcoólica/enzimologia , Doença Aguda , Adulto , Idoso , Estudos de Casos e Controles , Cuidados Críticos , Progressão da Doença , Feminino , Hospitalização , Humanos , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Necrose/enzimologia , Neutrófilos/enzimologia , Neutrófilos/imunologia , Pancreatite Necrosante Aguda/complicações , Pancreatite Necrosante Aguda/patologia , Pancreatite Necrosante Aguda/terapia , Pancreatite Alcoólica/complicações , Pancreatite Alcoólica/patologia , Pancreatite Alcoólica/terapia , Estudos Prospectivos , Insuficiência Respiratória/enzimologia , Insuficiência Respiratória/etiologia , Adulto Jovem
11.
Clin Pharmacol Ther ; 113(4): 887-895, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36622792

RESUMO

Self-perceived statin-associated muscle symptoms (SAMS) are prevalent, but only a minority is drug-dependent. Diagnostic biomarkers are not yet identified. The local statin exposure in skeletal muscle tissue may correlate to the adverse effects. We aimed to determine whether atorvastatin metabolites in blood reflect the corresponding metabolite levels in skeletal muscle, and whether genetic variants of statin transporters modulate this relationship. We also addressed atorvastatin metabolites as potential objective biomarkers of SAMS. Muscle symptoms were examined in patients with coronary disease and self-perceived SAMS during 7 weeks of double-blinded treatment with atorvastatin 40 mg/day and placebo in randomized order. A subset of 12 patients individually identified with more muscle symptoms on atorvastatin than placebo (confirmed SAMS) and 15 patients with no difference in muscle symptom intensity (non-SAMS) attended the present follow-up study. All received 7 weeks of treatment with atorvastatin 40 mg/day followed by 8 weeks without statins. Biopsies from the quadriceps muscle and blood plasma were collected after each treatment period. Strong correlations (rho > 0.7) between muscle and blood plasma concentrations were found for most atorvastatin metabolites. The impact of the SLCO1B1 c.521T>C (rs4149056) gene variant on atorvastatin's systemic pharmacokinetics was translated into muscle tissue. The SLCO2B1 c.395G>A (rs12422149) variant did not modulate the accumulation of atorvastatin metabolites in muscle tissue. Atorvastatin pharmacokinetics in patients with confirmed SAMS were not different from patients with non-SAMS. In conclusion, atorvastatin metabolite levels in skeletal muscle and plasma are strongly correlated, implying that plasma measurements are suitable proxies of atorvastatin exposure in muscle tissue. The relationship between atorvastatin metabolites in plasma and SAMS deserves further investigation.


Assuntos
Doença das Coronárias , Inibidores de Hidroximetilglutaril-CoA Redutases , Humanos , Atorvastatina/efeitos adversos , Atorvastatina/farmacocinética , Biomarcadores , Doença das Coronárias/tratamento farmacológico , Seguimentos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacocinética , Transportador 1 de Ânion Orgânico Específico do Fígado/genética , Músculo Esquelético
12.
Br J Clin Pharmacol ; 73(1): 106-14, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21707700

RESUMO

AIMS: To investigate the relationships between pretreatment folate concentrations, MTX pharmacokinetics and acute toxicities following high dose methotrexate (HD MTX) therapy. METHODS: MTX and its major extracellular metabolite 7-OH-MTX were measured in eight serum samples per HD MTX cycle in 65 consecutive osteosarcoma patients (288 cycles) and AUC (area under the blood concentration-time curve) was calculated. Pretreatment concentrations of folate in serum (S) and erythrocytes (ER) were determined. Hepatic, renal and haematological toxicities, assessed by routine laboratory parameters, as well as mucositis were graded according to National Cancer Institute Common Terminology Criteria for adverse events (CTCAE v.3.0). Dermatitis and pleuritis were reported as occurred or not. RESULTS: S- and ER-folate pretreatment concentrations increased significantly with increasing number of HD MTX cycles (P < 0.001). ER-folate pretreatment concentrations were higher among males (median 610 nmol l⁻¹, 95% CI 550, 680) compared with females (median 465 nmol l⁻¹, 95% CI 430, 520, P < 0.001), but showed no correlation with MTX or 7-OH-MTX pharmacokinetics. We found correlations between alanine aminotransferase peak concentration (ALAT(max) ) and clearance of MTX (P < 0.001), gender (P < 0.001), age (P < 0.001) and 7-OH-MTX concentrations (P < 0.001), the latter being the main factor influencing ALAT(max) . CONCLUSION: Our results suggest that 7-OH-MTX is involved in the development of HD MTX hepatic toxicity and that young female patients are most affected.


Assuntos
Antimetabólitos Antineoplásicos/farmacocinética , Neoplasias Ósseas/metabolismo , Ácido Fólico/metabolismo , Metotrexato/farmacocinética , Osteossarcoma/metabolismo , Adolescente , Adulto , Fatores Etários , Antimetabólitos Antineoplásicos/efeitos adversos , Área Sob a Curva , Criança , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Metotrexato/efeitos adversos , Pessoa de Meia-Idade , Proteína Carregadora de Folato Reduzido/metabolismo , Fatores Sexuais , Resultado do Tratamento , Adulto Jovem
13.
Basic Clin Pharmacol Toxicol ; 129(6): 427-436, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34396687

RESUMO

Because several steroid hormones are metabolized to their respective 6ß-hydroxy forms by CYP3A4 and CYP3A5, these isoenzymes have been assumed to metabolize the immunosuppressive drug prednisolone, with conflicting results in the literature with respect to their relative importance. A direct study of the metabolism of prednisolone by microsomal CYP3A4 and CYP3A5 is missing. The aim of this in vitro study was to investigate the relative importance of recombinant CYP3A4 and recombinant CYP3A5 in the metabolism of prednisolone and to compare the extent of formation of 6ß-OH-prednisolone by the two enzymes. Through in vitro incubations using rCYP3A4 and rCYP3A5 enzymes, intrinsic clearance (CLint ) of prednisolone was determined by the substrate depletion approach. Formation of the metabolite 6ß-OH-prednisolone by rCYP3A4 and rCYP3A5, respectively, was compared. Prednisolone concentrations were measured, and its metabolite 6ß-OH-prednisolone was identified using a HPLC-MS/MS in-house method. CLint for prednisolone by rCYP3A5 was less than 26% relative to rCYP3A4. Formation of 6ß-OH-prednisolone by rCYP3A5 was less than 11% relative to rCYP3A4. The study indicates that 6ß-hydroxylation of prednisolone assessed in vitro in recombinant CYP enzymes depends on rCYP3A4 rather than rCYP3A5 and that CYP3A5 may be responsible for the formation of other prednisolone metabolite(s) in addition to 6ß-OH-prednisolone.


Assuntos
Citocromo P-450 CYP3A/metabolismo , Glucocorticoides/metabolismo , Prednisolona/análogos & derivados , Animais , Cromatografia Líquida de Alta Pressão , Humanos , Hidroxilação , Insetos , Microssomos/enzimologia , Prednisolona/metabolismo , Espectrometria de Massas em Tandem
14.
BMC Res Notes ; 5: 418, 2012 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-22871021

RESUMO

BACKGROUND: This pilot study (ClinicalTrials.gov ID: NCT01507701) assessed the feasibility and safety of clonidine in adolescent chronic fatigue syndrome (CFS). Specifically, we assessed clonidine dosage in relation to a) plasma concentration levels, b) orthostatic cardiovascular responses, and c) possible adverse effects. FINDINGS: Five adolescent CFS patients (14-19 years old) received 50 µg clonidine twice per day during 14 days in an open, uncontrolled design. Plasma concentration of clonidine was assayed by standard laboratory methods. Changes in orthostatic cardiovascular responses were assessed by a 20o head-up tilt-test (HUT). Adverse effects were mapped by a questionnaire.After 14 days, C0 median (range) of clonidine was 0.21 (0.18-0.36) µg/L, and Cmax median (range) of clonidine was 0.41 (0.38-0.56) µg/L. Also, supine blood pressures and heart rate were lower during clonidine treatment, and the HUT response was closer to the normal response. No serious adverse effects were registered. CONCLUSION: Clonidine 50 µg BID seems to be safe enough to proceed from a pilot study to a controlled trial in a select group of adolescents with CFS (ClinicalTrials.gov ID: NCT01040429).


Assuntos
Clonidina/uso terapêutico , Síndrome de Fadiga Crônica/tratamento farmacológico , Adolescente , Clonidina/efeitos adversos , Síndrome de Fadiga Crônica/fisiopatologia , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Noruega , Projetos Piloto , Teste da Mesa Inclinada , Adulto Jovem
15.
Pancreas ; 40(7): 1097-102, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21926545

RESUMO

OBJECTIVES: Complement activation may play a prominent role in acute pancreatitis (AP). Mannan-binding lectin (MBL) and MBL-associated serine protease 2 (MASP-2) participate in complement activation. The objective of the present study was to evaluate the role of MBL and MASP-2 as markers in AP with regard to etiology, inflammatory activity, severity, and development of multiorgan failure. METHODS: Sixty patients with AP were included. All patients were diagnosed and treated according to a standardized regimen. Blood samples were obtained immediately on admission and again on days 1, 2, and 14. RESULTS: Both MBL (P < 0.001) and MASP-2 (P = 0.002) levels changed significantly over time, but without any significant relation to severity, multiorgan failure, or mortality. We found significantly higher levels of MBL (P = 0.04) in alcohol- than in gallstone-induced AP, but no significant difference in MASP-2 levels. CONCLUSIONS: The MBL and MASP-2 acted as acute-phase reactants, but overall, they were not markers for severity, multiorgan failure, nor for mortality in AP. Our results suggest that MBL and MASP-2 play only a minor role in the inflammatory response in AP.


Assuntos
Ativação do Complemento , Lectina de Ligação a Manose/sangue , Serina Proteases Associadas a Proteína de Ligação a Manose/metabolismo , Insuficiência de Múltiplos Órgãos/etiologia , Pancreatite Alcoólica/enzimologia , Pancreatite/enzimologia , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteína C-Reativa/metabolismo , Estudos de Casos e Controles , Feminino , Cálculos Biliares/complicações , Humanos , Mediadores da Inflamação/sangue , Interleucina-6/sangue , Masculino , Pessoa de Meia-Idade , Insuficiência de Múltiplos Órgãos/enzimologia , Insuficiência de Múltiplos Órgãos/imunologia , Insuficiência de Múltiplos Órgãos/mortalidade , Pancreatite/etiologia , Pancreatite/imunologia , Pancreatite/mortalidade , Pancreatite Alcoólica/etiologia , Pancreatite Alcoólica/imunologia , Pancreatite Alcoólica/mortalidade , Prognóstico , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Fatores de Tempo , Adulto Jovem
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