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BACKGROUND: Efavirenz (EFV) is a drug used to treat HIV. Low plasma concentrations of EFV result in suboptimal viral suppression, whereas high concentrations can cause adverse neuropsychiatric side reactions. Some studies have identified a correlation between the plasma concentrations of EFV metabolites and neurotoxicity. To our knowledge, no studies have investigated the metabolism of EFV in young children and its effect on treatment outcomes. Therefore, the aim of this study was to develop and validate a method for quantifying EFV and its metabolites in human plasma derived from children. METHODS: Sample preparation was performed using protein precipitation of 100 µL plasma. Thereafter, an aliquot of the supernatant was used to quantify EFV, 7-hydroxyefavirenz (7-OH-EFV), 8-hydroxyefavirenz (8-OH-EFV), and a newly discovered metabolite ("EFAdeg") associated with 8-OH-EFV. A second aliquot of the supernatant was hydrolyzed using ß-glucuronidase/arylsulfatase and used with the first aliquot to quantify phase II metabolites. The analyses were performed using a Dionex Ultimate 3000RS LC-system coupled with a Q Exactive Orbitrap mass spectrometer. RESULTS: The method has a measuring range of 100-50,000 ng/mL (EFV, 8-OH-EFV), 125-25,000 ng/mL (7-OH-EFV), and 200-10,000 ng/mL ("EFAdeg"). All criteria of the European Medicines Agency guidelines regarding precision, accuracy, and selectivity were met. Of note, carryover must be considered for 8-OH-EFV. Overall, the validated method was successfully applied to plasma samples obtained from children and confirmed the presence of the newly discovered metabolite, "EFAdeg." CONCLUSIONS: An LC-HRMS/MS method for the quantification of EFV and its phase I and II metabolites was developed and validated. This method is suitable for analyzing plasma samples from children. Furthermore, studies using this method identified an additional metabolite that may influence the concentration of 8-OH-EFV in patient samples.
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Alcinos , Benzoxazinas , Ciclopropanos , Espectrometria de Massas em Tandem , Humanos , Benzoxazinas/sangue , Benzoxazinas/farmacocinética , Cromatografia Líquida/métodos , Espectrometria de Massas em Tandem/métodos , Criança , Fármacos Anti-HIV/sangue , Fármacos Anti-HIV/farmacocinética , Pré-Escolar , Infecções por HIV/tratamento farmacológico , Infecções por HIV/sangue , Reprodutibilidade dos TestesRESUMO
PURPOSE: Routine therapeutic drug monitoring of apixaban is currently not recommended but may however be warranted in some situations and for some patient groups to provide better and safer treatment. Due to limited data on apixaban concentrations in different subpopulations, it is still unclear which group of patients could possibly gain from monitoring. The purpose of this study was to examine apixaban exposure in patients with obesity compared with normal-weight patients. METHODS: Forty patients with obesity (mean BMI 39.4 kg/m2) and 40 controls with normal weight (mean BMI 23.4 kg/m2), treated with apixaban 5 mg twice daily were included. The patients were matched for age, sex, and renal function. Trough and peak apixaban concentrations were measured with LCâMS/MS methodology. RESULTS: The median trough concentrations in patients with obesity (58.7, range 10.7-200.7 ng/ml) were slightly higher than those in patients with normal weight (52.0, range 31.0-150.9 ng/ml) (p < 0.05). Notably, the variability in trough concentration was considerably higher in patients with obesity. Peak concentrations were similar in both groups, with a median of 124.5 ng/ml (range 82.0-277.5) and 113.5 ng/ml (range 75.5-334.6) in patients with obesity and normal weight, respectively. CONCLUSION: Apixaban exposure did not vary substantially between obese and normal weight matched controls, implying that general dose adjustments are not required. However, vast interindividual variability was observed in patients with obesity, suggesting that measuring the concentrations could be valuable for specific patients. Further research is needed to identify which specific patients may benefit from this approach.
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Monitoramento de Medicamentos , Inibidores do Fator Xa , Obesidade , Pirazóis , Piridonas , Humanos , Piridonas/sangue , Piridonas/farmacocinética , Piridonas/administração & dosagem , Piridonas/uso terapêutico , Pirazóis/sangue , Pirazóis/farmacocinética , Pirazóis/uso terapêutico , Pirazóis/administração & dosagem , Feminino , Obesidade/sangue , Masculino , Pessoa de Meia-Idade , Inibidores do Fator Xa/sangue , Inibidores do Fator Xa/farmacocinética , Inibidores do Fator Xa/uso terapêutico , Inibidores do Fator Xa/administração & dosagem , Adulto , Idoso , Monitoramento de Medicamentos/métodos , Espectrometria de Massas em Tandem , Estudos de Casos e ControlesRESUMO
Selective androgen receptor modulators (SARMs) are prohibited by the World Anti-Doping Agency (WADA) since 2008. Similarly, to anabolic androgenic steroids (AAS), SARMs are detrimental to health not only in athletes but also in the general population. However, studies of the occurrence of SARMs outside of sport are scarce. Swedish healthcare samples from the Drugs of Abuse Laboratory at Karolinska were analyzed using WADA-accredited screening methods at the Doping Control Laboratory in Stockholm to estimate the frequency of SARM use outside of the WADA laboratories. Twenty (4%) of the male urine samples (n = 542) were positive for SARMs, whereas none of the analyzed female samples (n = 100) contained any SARMs. The top three SARMs found were LGD-4033 followed by RAD140 and ostarine. Two or more SARMs were found in >50% of the SARM-positive samples. AASs were identified in 40% of samples containing SARMs. A difference between genders was observed where 34% male and 7% female samples contained AAS. Many samples displayed testosterone/epitestosterone values indicative of testosterone intake, without presence of other AAS, and hence, there is a risk that these samples are being falsely reported as negative. Our results indicate that SARM use might be a concern outside of sport. Subsequently, in addition to AAS, the healthcare system should also be informed about SARM abuse and the associated adverse side effects.
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Rationale: Patients with severe asthma are dependent upon treatment with high doses of inhaled corticosteroids (ICS) and often also oral corticosteroids (OCS). The extent of endogenous androgenic anabolic steroid (EAAS) suppression in asthma has not previously been described in detail. The objective of the present study was to measure urinary concentrations of EAAS in relation to exogenous corticosteroid exposure. Methods: Urine collected at baseline in the U-BIOPRED (Unbiased Biomarkers for the Prediction of Respiratory Disease outcomes) study of severe adult asthmatics (SA, n=408) was analysed by quantitative mass spectrometry. Data were compared to that of mild-to-moderate asthmatics (MMA, n=70) and healthy subjects (HC, n=98) from the same study. Measurements and main results: The concentrations of urinary endogenous steroid metabolites were substantially lower in SA than in MMA or HC. These differences were more pronounced in SA patients with detectable urinary OCS metabolites. Their dehydroepiandrosterone sulfate (DHEA-S) concentrations were <5% of those in HC, and cortisol concentrations were below the detection limit in 75% of females and 82% of males. The concentrations of EAAS in OCS-positive patients, as well as patients on high-dose ICS only, were more suppressed in females than males (p<0.05). Low levels of DHEA were associated with features of more severe disease and were more prevalent in females (p<0.05). The association between low EAAS and corticosteroid treatment was replicated in 289 of the SA patients at follow-up after 12-18â months. Conclusion: The pronounced suppression of endogenous anabolic androgens in females might contribute to sex differences regarding the prevalence of severe asthma.
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When testing for anabolic androgenic steroids (AAS) outside sports communities, for example, in healthcare and forensic medicine, urine is the matrix of choice. However, there are drawbacks with urinary sampling, and serum might be useful as a complementary matrix. The aim was to develop an LC-MS/MS method for serum measuring AAS frequently used outside of sport, including testosterone (T), steroid esters, and eight other synthetic AAS. The sample pretreatment included sample precipitation and evaporation. Limit of quantification for the AAS was 0.05-0.5 ng/mL, and linearity was 0.05-20 ng/mL for most of the substances. Generally, the within- and between-day CV results, matrix effect, and process efficiency were <15%. The AAS were stable for at least 6 months at -20°C. Serum samples were obtained from previous studies. A novel finding from an administration study was that T enanthate was present in serum even after 5 years of storage at -20°C. Serum samples from self-reporting AAS individuals, where T esters were detected, were positive for testosterone using the urinary testosterone/epitestosterone criterion >10. Of those identified as positive in traditional urinary doping tests (n = 15), AAS in serum were found in 80% of the subjects. Our results show that serum may be a valid complementary matrix to urine samples for AAS testing.
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Anabolizantes , Dopagem Esportivo , Humanos , Esteróides Androgênicos Anabolizantes , Cromatografia Líquida , Anabolizantes/urina , Espectrometria de Massas em Tandem/métodos , Congêneres da Testosterona , Testosterona/urina , ÉsteresRESUMO
It has been suggested to longitudinally monitor Insulin-like growth factor I (IGF-I) as a biomarker for the detection of recombinant growth hormone (GH). Subsequently, it is of interest to understand any confounders of endogenous IGF-I. Herein we have studied if serum IGF-I concentration is affected by the intake of anabolic androgenic steroids (AAS) and the potential connection between IGF-I and klotho protein. Moreover, the usefulness of klotho as a biomarker for recombinant GH intake was assessed in healthy male volunteers. An ongoing administration of AAS did not affect the levels of IGF-I. Klotho protein was ~30% higher in men with an ongoing AAS use compared to those with previous (>2 months ago) AAS use, and the serum klotho protein correlated negatively with luteinizing hormone (LH) (r s = -0.38, p = 0.04) and follicle stimulating hormone (FSH) (r s = -0.35, p = 0.05) levels. Serum IGF-I and klotho concentrations showed no correlation in the AAS using population but showed a strong negative correlation in healthy volunteers (r s = -0.86, p = 0.006). The intake of recombinant GH did not affect the serum concentrations of the klotho levels. In conclusion, IGF-I was not affected by supra-physiological AAS doses in men. Interestingly, an association between AAS intake and serum klotho was seen. The usefulness of klotho as an androgen biomarker warrants further studies, whereas klotho can be discarded as a promising biomarker for GH doping.
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The World Anti-Doping Agency (WADA) has recently implemented dried blood spots (DBSs) as a matrix for doping control. However, specifications regarding the analysis of the class of prohibited substances called erythropoietin (EPO) receptor agonists (ERAs) from DBSs are not yet described. The aim of this study was to find optimal conditions (sample volume and storage) to sensitively detect endogenous erythropoietin (hEPO) and prohibited ERAs from DBSs and compare detection limits to WADA-stipulated minimum required performance levels (MRPLs) for ERAs in serum/plasma samples. Venous whole blood was spotted onto Whatman 903 DBS cards with primarily 60 µl of blood, but various volumes from 20 to75 µl were tested. All samples were immunopurified with MAIIA EPO Purification Gel kit (EPGK) and analysed with sodium N-lauroylsarcosinate polyacrylamide gel electrophoresis (SAR-PAGE) and Western blot. Sixty-microliter DBSs allowed the detection of the four main ERAs (BRP, NESP, CERA and EPO-Fc) at concentrations close to WADA's MRPLs described for 500 µl of serum/plasma. Different storage temperatures, from -20°C to 37°C, were evaluated and did not affect ERA detection. A comparison of the detection of endogenous EPO from the different anti-doping matrices (urine, serum and DBSs produced from upper arm capillary blood) from five participants for 6 weeks was performed. Endogenous EPO extracted from DBSs showed intra-individual variations in male and female subjects, but less than in urine. Doping controls would benefit from the stability of ERAs on DBSs: It can be a complementary matrix for ERA analysis, particularly in the absence of EPO signals in urine.
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Dopagem Esportivo , Hematínicos , Receptores da Eritropoetina , Detecção do Abuso de Substâncias , Teste em Amostras de Sangue Seco , Eletroforese em Gel de Poliacrilamida , Feminino , Hematínicos/análise , Humanos , Masculino , Receptores da Eritropoetina/agonistas , Detecção do Abuso de Substâncias/métodosRESUMO
(1) Background: Efavirenz plasma concentration displays wide between-patient variability partly due to pharmacogenetic variation and autoinduction. Pediatric data on efavirenz pharmacokinetics and the relevance of pharmacogenetic variation are scarce, particularly from sub-Saharan Africa, where >90% of HIV-infected children live and population genetic diversity is extensive. We prospectively investigated the short- and long-term effects of efavirenz auto-induction on plasma drug exposure and the influence of pharmacogenetics among HIV-infected Ethiopian children. (2) Method: Treatment-naïve HIV-infected children aged 3-16 years old (n = 111) were enrolled prospectively to initiate efavirenz-based combination antiretroviral therapy (cART). Plasma efavirenz concentrations were quantified at 4, 8, 12, 24, and 48 weeks of cART. Genotyping for CYP2B6, CYP3A5, UGT2B7, ABCB1, and SLCO1B1 common functional variant alleles was performed. (3) Results: The efavirenz plasma concentration reached a peak at two months, declined by the 3rd month, and stabilized thereafter, with no significant difference in geometric mean over time. On average, one-fourth of the children had plasma efavirenz concentrations ≥4 µg/mL. On multivariate analysis, CYP2B6*6 and ABCB1c.3435 C > T genotypes and low pre-treatment low-density lipoprotein (LDL) were significantly associated with higher plasma efavirenz concentration regardless of treatment duration. Duration of cART, sex, age, nutritional status, weight, and SLCO1B, CYP3A5, UGT2B7, and ABCB1 rs3842 genotypes were not significant predictors of efavirenz plasma exposure. (4) Conclusion: Pre-treatment LDL cholesterol and CYP2B6*6 and ABCB1c.3435 C > T genotypes predict efavirenz plasma exposure among HIV-infected children, but treatment-duration-dependent changes in plasma efavirenz exposure due to auto-induction are not statistically significant.
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In some clinical situations, measurements of anticoagulant effect of apixaban may be needed. We investigated the inter- and intra-individual apixaban variability in patients with atrial fibrillation and correlated these results with clinical outcome. We included 62 patients receiving either 5 mg (A5, n = 32) or 2.5 mg (A2.5, n = 30) apixaban twice-daily. We collected three trough and three peak blood samples 6-8 weeks apart. Apixaban concentration was measured by liquid chromatography-tandem mass-spectrometry (LC-MS/MS) and by anti-Xa. Patients on A2.5 were older, had lower creatinine clearance, higher CHA2DS2VASc (4.7 ± 1.0 vs. 3.4 ± 1.7) and lower trough (85 ± 39 vs. 117 ± 53 ng/mL) and peak (170 ± 56 vs. 256 ± 91 ng/mL) apixaban concentrations than patients on A5 (all p < 0.01). In patients on A5, LC-MS/MS showed a significant difference between through levels and between peak levels (p < 0.01). During apixaban treatment, 21 patients suffered bleeding (2 major). There was no association between bleeding and apixaban concentrations or variability. Four patients who suffered thromboembolic event had lower peak apixaban concentrations than patients without it (159 ± 13 vs. 238 ± 88 ng/mL, p = 0.05). We concluded, that there was a significant intra- and inter-individual variability in apixaban trough and peak concentrations. Neither variability nor apixaban concentrations were associated with clinical outcomes.
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Fibrilação Atrial/tratamento farmacológico , Pirazóis/uso terapêutico , Piridonas/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/sangue , Feminino , Hemorragia/induzido quimicamente , Humanos , Masculino , Pirazóis/efeitos adversos , Pirazóis/sangue , Pirazóis/farmacologia , Piridonas/efeitos adversos , Piridonas/sangue , Piridonas/farmacologia , Tromboembolia/induzido quimicamente , Resultado do TratamentoRESUMO
Praziquantel (PZQ) and dihydroartemisinin-piperaquine (DHP) combination recently showed superior effectiveness than PZQ alone to treat intestinal schistosomiasis. In this follow-up study, we investigated the effect of DHP co-administration on the pharmacokinetics of PZQ and its enantiomers among 64 Schistosoma mansoni infected children treated with PZQ alone (n = 32) or PZQ + DHP combination (n = 32). Plasma samples collected at 0, 1, 2, 4, 6, and 8 h post-dose were quantified using UPLCMS/MS. The geometric mean (GM) of AUCs for total PZQ, R-PZQ and S-PZQ were significantly higher among children who received PZQ + DHP than PZQ alone. The geometric mean ratio (GMR) and (90% CI) of AUC0-∞ for PZQ + DHP to PZQ for total PZQ, R-PZQ, and S-PZQ were 2.18 (1.27, 3.76), 3.98 (2.27, 7.0) and 1.86 (1.06, 3.28), respectively. The GMR and (90% CI) of AUC0-8 for total PZQ, R-PZQ, and S-PZQ were 1.73 (1.12, 2.69), 2.94 (1.75, 4.92), and 1.50 (0.97, 2.31), respectively. The GM of Cmax for total PZQ, R-PZQ and S-PZQ were significantly higher among those who received PZQ + DHP than PZQ alone. The GMR (90% CI) of Cmax of PZQ + DHP to PZQ for total PZQ, R-PZQ, and S-PZQ were 1.75 (1.15, 2.65), 3.08 (1.91, 4.96), and 1.50 (1.0, 2.25%), respectively. The 90% CI of the GMRs for both AUCs and Cmax for total PZQ, R-PZQ, and S-PZQ were outside the acceptable 0.80-1.25 range, indicating that the two treatment arms were not bioequivalent. DHP co-administration significantly increases systemic PZQ exposure, and this may contribute to increased effectiveness of PZQ + DHP combination therapy than PZQ alone to treat schistosomiasis.
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CONTEXT: Little is known about how exogenous testosterone (T) affects the steroid profile in women. More knowledge would give the antidoping community keys as to how to interpret tests and detect doping. OBJECTIVE: This work aimed to investigate the steroid profile in serum and urine in young healthy women after T administration. METHODS: In a randomized, double-blind, placebo-controlled study, 48 healthy young women were assigned to daily treatment with T cream (10 mg) or placebo (1:1) for 10 weeks. Urine and blood were collected before and at the end of treatment. Serum steroids were analyzed with liquid chromatography-tandem mass spectrometry, and urine levels of T, epitestosterone (E), and metabolites included in the Athlete Biological Passport (ABP) were analyzed with gas chromatography-tandem mass spectrometry. RESULTS: In serum, T and dihydrotestosterone levels increased, whereas sex hormone-binding globulin and 17-hydroxyprogesterone decreased after T treatment as compared to placebo. In urine, T and 5α-androstanediol increased in the T group. The median T increase in serum was 5.0-fold (range, 1.2-18.2) and correlated to a 2.2-fold (range, 0.4-14.4) median increase in T/E in urine (rs = 0.76). Only 2 of the 24 women receiving T reached the T/E cutoff ratio of 4, whereas when the results were added to the ABP, 6 of 15 participants showed atypically high T/E (40%). In comparison, 22/24 women in the T group increased serum T more than 99.9% of the upper confidence interval of nontreated values. CONCLUSION: It seems that the T/E ratio is not sufficient to detect exogenous T in women. Serum total T concentrations could serve as a complementary marker of doping.
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Esteroides/sangue , Esteroides/urina , Testosterona/administração & dosagem , Adolescente , Adulto , Atletas , Análise Química do Sangue/métodos , Cromatografia Líquida , Dopagem Esportivo , Método Duplo-Cego , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Voluntários Saudáveis , Humanos , Placebos , Esteroides/metabolismo , Detecção do Abuso de Substâncias/métodos , Espectrometria de Massas em Tandem , Testosterona/sangue , Testosterona/urina , Urinálise/métodos , Adulto JovemRESUMO
AIM: Children with epilepsy often have concomitant diagnoses. Dried blood spot samples for drug monitoring can be collected by parents at home as an alternative to traditional sampling. This mixed-method study aimed to understand the parents' perspectives on blood self-sampling from their children and to identify factors contributing to successful sampling. METHOD: Parents who had collected a sample from their child during a visit to the neuropediatric clinic were asked to fill in a questionnaire. To get in-depth information and individual perspectives, parents and nurses participated in semi-structured interviews and analysed with thematic analysis. RESULTS: The results from questionnaires (n = 64) and interviews (n = 9) were interpreted together. Watching an instruction video and practical training contributed to successful sampling. 97% of the parents managed to collect a sample, 72% thought it was easy to perform, and 80% found self-sampling at home desirable. Factors for success were as follows: high motivation, prepared parents with pre-understanding, a pragmatic attitude, flexible education, effective communication and willingness to take on the role as a performer. Risk factors were as follows: conflict, fear, unprepared parents, confused or worried children. CONCLUSION: Voluntary self-sampling at home for parents of children with epilepsy is feasible and can reduce stress factors in everyday life.
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Epilepsia , Criança , Monitoramento de Medicamentos , Epilepsia/diagnóstico , Humanos , Motivação , Pais , Pesquisa Qualitativa , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Suboptimal anti-TB drugs exposure may cause multidrug-resistant TB. The role of African predominant SLCO1B1 variant alleles on rifampicin pharmacokinetics and the subsequent effect on the occurrence of Mycobacterium tuberculosis-rifampicin sensitivity needs to be defined. We describe the rifampicin population pharmacokinetics profile and investigate the relevance of SLCO1B1 genotypes to rifampicin pharmacokinetics and rifampicin-TB sensitivity status. METHODS: Fifty patients with TB (n=25 with rifampicin-resistant TB and n=25 with rifampicin-susceptible TB) were genotyped for SLOC1B1 rs4149032 (g.38664C>T), SLOC1B1*1B (c.388A>G) and SLOC1B1*5 (c.521 T>C). Steady state plasma rifampicin levels were determined among patients infected with rifampicin-sensitive TB. Data were analysed using NONMEM to estimate population rifampicin pharmacokinetics as well as the effect of SLOC1B1 genotypes on rifampicin pharmacokinetics and on rifampicin-TB sensitivity status. RESULTS: Overall allele frequencies of SLOC1B1 rs4149032, *1B and *5 were 0.66, 0.90 and 0.01, respectively. Median (IQR) Cmax and Tmax were 10.2 (8.1-12.5) mg/L and 1.7 (1.125-2.218) h, respectively. Twenty-four percent of patients exhibited Cmax below the recommended 8-24 mg/L range. SLOC1B1 genotypes, gender and age did not influence rifampicin pharmacokinetics or TB-rifampicin sensitivity. CONCLUSIONS: Although SLOC1B1 genotype, age and gender do not influence either rifampicin pharmacokinetics or rifampicin-TB sensitivity status, one in every four Ugandan TB patients achieve subtherapeutic plasma rifampicin concentrations.
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Antituberculosos/farmacocinética , Transportador 1 de Ânion Orgânico Específico do Fígado/genética , Farmacogenética , Rifampina/farmacocinética , Frequência do Gene , Genótipo , Humanos , UgandaRESUMO
BACKGROUND: Routine laboratory monitoring of rivaroxaban and dose adjustment relating to exposure is currently not recommended. However, in certain clinical situations, assessment of rivaroxaban levels is desirable. OBJECTIVES: To examine inter- and intra-subject plasma rivaroxaban variability in patients with atrial fibrillation (AF) and to correlate these results to clinical outcomes. PATIENTS/METHODS: We included 60 patients with AF treated with rivaroxaban: half on 20 mg daily (R20) and half on 15 mg daily (R15). Three trough and peak blood samples were collected with an interval of 6-8 weeks apart. Plasma rivaroxaban concentration was measured directly by liquid chromatography-tandem mass-spectrometry (LC-MS/MS) and indirectly by anti-Xa for rivaroxaban, prothrombin time (PT), and activated partial thromboplastin time (APTT). RESULTS: Patients on R15 were older (76 ± 6 vs 71 ± 6 years), had lower creatinine clearance (60 ± 26 vs 99 ± 32 mL/min), higher CHADS2 (2.5 ± 1.2 vs 1.8 ± 1.3), all p < 0.01, but had similar rivaroxaban concentrations in trough samples to patients on R20. There was no significant intra-individual variability for trough or peak rivaroxaban concentration assessed by LC-MS/MS, anti-Xa, or PT. Trough rivaroxaban levels determined by LC-MS/MS (48 ± 30 vs 34 ± 26, p = 0.02) and anti-Xa, but not with PT and APTT, were higher in patients with bleeding than in patients without it. CONCLUSIONS: There is a pronounced inter-, but not intra-individual variability in the rivaroxaban trough levels in patients with AF. Assessment of trough rivaroxaban concentration with LC-MS/MS or anti-Xa, but not with APTT or PT, may help to identify patients at increased risk of bleeding.
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Fibrilação Atrial/tratamento farmacológico , Variação Biológica Individual , Variação Biológica da População , Inibidores do Fator Xa/farmacologia , Hemorragia/epidemiologia , Rivaroxabana/farmacologia , Idoso , Idoso de 80 Anos ou mais , Testes de Coagulação Sanguínea/estatística & dados numéricos , Relação Dose-Resposta a Droga , Monitoramento de Medicamentos/estatística & dados numéricos , Inibidores do Fator Xa/uso terapêutico , Feminino , Hemorragia/induzido quimicamente , Humanos , Masculino , Medição de Risco , Rivaroxabana/uso terapêuticoRESUMO
BACKGROUND: Dried blood spot (DBS) is an attractive matrix alternative to plasma for the measurement of antiepileptic drug concentrations with the possibility of self-sampling at home. The aim of this study was to evaluate whether DBS concentrations from a children population could be used as an alternative to plasma concentrations in a clinical routine laboratory. METHODS: Children with epilepsy using carbamazepine (CBZ), lamotrigine (LTG), levetiracetam (LEV), or valproic acid (VPA) had capillary blood collected for routine plasma analysis. DBS samples were collected by guardians or nurses, and the quality of sampling was compared between the groups. DBS samples were analyzed with liquid chromatography-tandem mass spectrometry methods and plasma samples with immunochemical methods. In the comparison between DBS and plasma concentrations, previously analyzed sample data were pooled with data in this study and resulted in 190 comparison pairs. A bioanalytical cross-validation according to European Medicines Agency was performed. Clinicians evaluated the results to understand if a DBS concentration was linked to a different clinical dose recommendation for the patient in comparison with plasma concentrations. RESULTS: Comparison of DBS sample quality showed that 2.3% of the capillary DBS collected by guardians were rejected and 8.0% of the capillary DBS collected by nurses. For DBS, a conversion factor of 0.85 for CBZ and 1.65 for VPA was applied for the comparison with plasma. LTG and LEV results were directly comparable. In the cross-validation, 88% of CBZ, 75% of LTG, 74% of LEV, and 94% of VPA comparisons were within 20% of the difference of the mean, although LEV had a few major differences (+31% to -40%). In 4 of the 190 comparisons, the clinical evaluation indicated a risk of conflicting decisions regarding the need for dose adjustment when using DBS concentrations. However, the risk of negative patient outcomes was considered negligible. CONCLUSIONS: Our study demonstrates that a combination of bioanalytical cross-validation and clinical evaluation is an effective way to describe the applicability of DBS as an alternative to plasma, taking into account how therapeutic drug monitoring is used in specific patient groups. For LTG, converted CBZ and VPA, DBS is a feasible alternative for self-sampling at home. DBS for LEV can only be recommended for nonadherence queries due to the high variability of the plasma/DBS concentration ratios.
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Anticonvulsivantes/sangue , Epilepsia/sangue , Plasma/química , Anticonvulsivantes/uso terapêutico , Criança , Teste em Amostras de Sangue Seco/métodos , Monitoramento de Medicamentos/métodos , Epilepsia/tratamento farmacológico , Feminino , Humanos , Masculino , Manejo de Espécimes/métodosRESUMO
CYP3A5 genotype is a major determinant of tacrolimus clearance, and has been shown to affect systemic tacrolimus metabolite/parent ratios in healthy volunteers, which may have implications for efficacy and toxicity. In a cohort of 50 renal transplant recipients who underwent quantification of CYP3A4 activity using the oral midazolam drug probe, we confirmed that CYP3A5 genotype is the single most important determinant of tacrolimus metabolite/parent ratio [CYP3A5 expressors displayed 2.7- and 2-fold higher relative exposure to 13-desmethyltacrolimus (DMT) and 31-DMT, respectively; P < 0.001]. There was, however, no relationship between CYP3A4 activity and tacrolimus metabolite/parent ratios. Additional analyses in 16 healthy volunteers showed that dual pharmacological inhibition of CYP3A4 and P-glycoprotein using itraconazole resulted in increased tacrolimus metabolite/parent ratios (+65%, +112%, and 25% for 13-, 15-, and 31-DMT, respectively; P < 0.01). This finding was confirmed in a cohort of nine renal transplant recipients who underwent tacrolimus pharmacokinetic assessments before and during CYP3A4 inhibition (58% increase in overall metabolite/tacrolimus ratio; P = 0.017).
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Citocromo P-450 CYP3A/genética , Rim/metabolismo , Tacrolimo/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Genótipo , Voluntários Saudáveis , Humanos , Imunossupressores/metabolismo , Transplante de Rim/métodos , Masculino , Midazolam/metabolismo , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
Background: Therapeutic drug monitoring (TDM) could improve current TB treatment, but few studies have reported pharmacokinetic data together with MICs. Objectives: To investigate plasma concentrations of rifampicin, isoniazid, pyrazinamide and ethambutol along with MICs. Methods: Drug concentrations of rifampicin, isoniazid, pyrazinamide and ethambutol were analysed pre-dose and 2, 4 and 6 h after drug intake at week 2 in 31 TB patients and MICs in BACTEC 960 MGIT were determined at baseline. The highest plasma concentrations at 2, 4 and 6 h post-dose (Chigh) were determined, as well as estimates of Chigh/MIC and area under the concentration-time curve (AUC0-6)/MIC including the corresponding ratios based on calculated free-drug concentrations. This trial was registered at www.clinicaltrials.gov (NCT02042261). Results: After 2 weeks of treatment, the median Chigh values for rifampicin, isoniazid, pyrazinamide and ethambutol were 10.0, 5.3, 41.1 and 3.3 mg/L respectively. Lower than recommended drug concentrations were detected in 42% of the patients for rifampicin (<8 mg/L), 19% for isoniazid (<3 mg/L), 27% for pyrazinamide (<35 mg/L) and 16% for ethambutol (<2 mg/L). The median Chigh/MIC values for rifampicin, isoniazid, pyrazinamide and ethambutol were 164, 128, 1.3 and 2.5, respectively, whereas the AUC0-6/MIC was 636 (range 156-2759) for rifampicin and 351 (range 72-895) for isoniazid. Conclusions: We report low levels of first-line TB drugs in 16%-42% of patients, in particular for rifampicin. There was a wide distribution of the ratios between drug exposures and MICs. The future use of MIC determinations in TDM is dependent on the development of a reference method and clinically validated pharmacokinetic/pharmacodynamic targets.
Assuntos
Antituberculosos/administração & dosagem , Antituberculosos/farmacocinética , Plasma/química , Tuberculose/tratamento farmacológico , Adulto , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Estudos ProspectivosRESUMO
Monitoring of antiepileptic drugs in children with epilepsy require multiple visits at a clinic for blood collection. Dried blood spot sampling is an alternative way of collection, performed at home by self-collection and can save time and costs for patients and family members. The aim was to develop and validate an LC-MS/MS dried blood spot method for carbamazepine, lamotrigine, levetiracetam and valproic acid with the requirements of using standard equipment and material in a routine laboratory setting. Whatman-903 filter paper was utilized, and discs were punched into a 96 well plate with an automated puncher and barcode reading. Extraction with methanol/water solution including internal standards on an orbital shaker was followed by a vacuum centrifuge step and reconstitution in mobile phase. Bioanalytical validation was performed according to guidelines from European Medicines Agency and additional dried blood spot specific validation. Calibration curves of the four included drugs had R2 values ≥0.994. Therapeutic relevant concentrations were well within measuring ranges. Within and -between run precision had %CV:s of 2.9-10.5%. Accuracy (%bias) was between -16.5% (lower limit of quantification) to +7.4%. Blood spots in a volume range of 15-50µL with hematocrit in expected ranges for this patient group were within precision and accuracy limits. To test the method, concentrations from dried blood spot venous and capillary patient samples (n=50) were compared with plasma concentrations. Good correlations for all four drugs with R2 of >0.92 was shown. In summary, a fast method for dried blood spots based on a 96 well format was developed for four commonly prescribed antiepileptic drugs. This validated method with traceability in sample preparation by bar code reading makes it suitable for the clinical laboratory.
Assuntos
Carbamazepina/sangue , Teste em Amostras de Sangue Seco/métodos , Piracetam/análogos & derivados , Espectrometria de Massas em Tandem/métodos , Triazinas/sangue , Ácido Valproico/sangue , Cromatografia Líquida/métodos , Feminino , Humanos , Lamotrigina , Levetiracetam , Modelos Lineares , Masculino , Piracetam/sangue , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Artemisinin-based combination therapy (ACT) is the first-line treatment of Plasmodium falciparum malaria. Since the introduction of artemether-lumefantrine (AL) for treatment of uncomplicated malaria in Sweden, treatment failures have been reported in adults. METHODS: A retrospective comparative analysis of treatment regimen for P. falciparum malaria in adults in Stockholm during 2000-2015 was performed to evaluate the effectiveness of AL. Parasite genotyping and drug concentrations were investigated in the AL treatment failures. RESULTS: Among the total 397 P. falciparum episodes, 310 were treated with oral regimen only (95 AL, 162 mefloquine, 36 atovaquone-proguanil [AP], and 17 others), and 87 were administered initial intravenous therapy (38 artesunate and 49 quinine) followed by oral treatments. Five late treatment failures were detected after AL and one slow response to AP. The effectiveness of AL alone was 94.7% (95% confidence interval [CI], 88.1%-98.3%), compared with 99.5% for other oral regimens (P = .003). All AL failures occurred in European men and the effectiveness in this group was only 73.7% (95% CI, 48.8%-90.0%). Genotyping confirmed recrudescence of the initial parasite populations and drug resistance markers revealed no clinically significant resistance patterns. Lumefantrine concentrations suggested subtherapeutic concentrations in at least 2 cases. CONCLUSIONS: Our findings indicate a high rate of symptomatic late treatment failures after 6-dose AL regime in nonimmune adults, especially in men. Our report warrants the need to establish optimal dosing of AL in adults and to alert clinicians about the importance of informing patients regarding the risk of parasites reappearing weeks after AL treatment.
Assuntos
Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Etanolaminas/uso terapêutico , Fluorenos/uso terapêutico , Malária Falciparum/tratamento farmacológico , Malária Falciparum/imunologia , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/imunologia , Viagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antimaláricos/administração & dosagem , Combinação Arteméter e Lumefantrina , Artemisininas/administração & dosagem , Combinação de Medicamentos , Resistência a Medicamentos , Etanolaminas/administração & dosagem , Feminino , Fluorenos/administração & dosagem , Genótipo , Humanos , Malária Falciparum/diagnóstico , Malária Falciparum/epidemiologia , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/genética , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Suécia/epidemiologia , Falha de Tratamento , Resultado do Tratamento , Adulto JovemRESUMO
Artemether-lumefantrine (AL) is a first-line treatment for uncomplicated malaria. Absorption of lumefantrine (LUM) is fat dependent, and in children, intake is recommended with milk. We investigated whether oil-fortified maize porridge can be an alternative when milk is not available. In an open-label pharmacokinetic study, Ugandan children <5 years with uncomplicated Plasmodium falciparum malaria were randomized to receive standard six-dose AL treatment [one tablet (20 mgA/120 mg LUM) if <15 kg and two tablets if >15 kg] with milk (A) or maize porridge plus oil (B). Parametric two-sample t-test was used to compare relative oral LUM bioavailability. The primary end-point was LUM exposure till 8 hr after the first dose (AUC0-8 hr ). Secondary outcome included day 7 concentrations (d7LUM ), LUM exposure between days 7 and 28 (AUCd7-28 ) and day 28 PCR-adjusted parasitological response. Evaluable children (n = 33) included 16 in arm A and 17 in arm B. The AUC0-8 hr was comparable between A and B [geometric mean (95% CI): 6.01 (3.26-11.1) versus 6.26 (4.5-8.43) hr*µg/mL, p = 0.9]. Less interindividual variability in AUC0-8 hr was observed in B (p = 0.01), but d7LUM and AUCd7-28 were comparable. Children receiving two tablets had significantly higher exposure than those receiving one tablet [median d7LUM (505 versus 289 ng/mL, p = 0.02) and AUCd7-28 (108 versus 41 hr*µg/mL, p = 0.006)]. One parasitological failure (d28 recrudescence) was observed. Our findings suggest that oil-fortified maize porridge can be an alternative to milk in augmenting absorption of LUM. The lower LUM exposure observed in children dosed with one AL tablet needs further attention.