RESUMO
PURPOSE: The clinical usefulness of therapeutic drug monitoring (TDM) of propafenone, a sodium channel blocker, has been unclear due to the lack of information regarding optimal blood sampling time and therapeutic concentration range. Antiarrhythmic effects of sodium channel blockers are affected by the activity of the cardiac sodium channel (SCN5A). We investigated the optimal sampling time and the clinical implication of the SCN5A promoter haplotype in propafenone TDM. METHODS: We evaluated serum concentrations of propafenone, the SCN5A promoter haplotype, and antiarrhythmic efficacy in 55 patients with supraventricular tachy-arrhythmias. Blood samples obtained 1.5-6 and 10-24 h after the last dose were categorized as peak and trough samples, respectively. RESULTS: The peak propafenone concentration was significantly higher in effectively treated patients than that in patients showing insufficient response (337 ± 213 vs. 177 ± 93 ng/mL, P = 0.005), but the trough propafenone concentration was not significantly different between the two groups (68 ± 48 vs. 42 ± 36 ng/mL). Clinically relevant propafenone efficacy was achieved significantly more often in SCN5A haplotype B carriers than in wild-type haplotype A homozygotes (90 vs. 60%, P < 0.05). Among the haplotype A homozygotes, peak propafenone concentration was higher in effectively treated patients than that in patients showing insufficient response (299 ± 177 vs. 177 ± 93 ng/mL, P = 0.061). CONCLUSION: The present study found that antiarrhythmic efficacy of propafenone was associated with peak propafenone concentration rather than trough concentration and was affected by the SCN5A promoter haplotype.
Assuntos
Monitoramento de Medicamentos/métodos , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Propafenona , Taquicardia Supraventricular/tratamento farmacológico , Adulto , Antiarrítmicos , Eletrocardiografia/métodos , Feminino , Haplótipos , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Variantes Farmacogenômicos , Regiões Promotoras Genéticas , Propafenona/administração & dosagem , Propafenona/sangue , Propafenona/farmacocinética , Bloqueadores dos Canais de Sódio/administração & dosagem , Bloqueadores dos Canais de Sódio/sangue , Bloqueadores dos Canais de Sódio/farmacocinética , Taquicardia Supraventricular/diagnóstico , Taquicardia Supraventricular/genética , Fatores de Tempo , Resultado do TratamentoRESUMO
Propafenone, a class Ic antiarrhythmic agent, is metabolized to 5-hydroxypropafeone (5-OHP) and N-depropylpropafenone (NDPP). Simultaneous determination of serum propafenone and its metabolites was performed using HPLC equipped with a conventional octadecylsilyl silica column and ultraviolet detector. The wavelength was set at 250 nm. Propafenone and its metabolites in the serum were extracted using diethyl ether. The mobile phase solution, comprising 1-pentanesulfonic acid sodium salt (0.1 m), acetonitrile and acetic acid (280:185:2.5, v/v/v), was pumped at a flow rate of 1 mL/min. The recoveries of propafenone, 5-OHP and NDPP were greater than 85, 82 and 60%, respectively, with the coefficients of variation (CVs) less than 5.4, 1.9 and 2.9%, respectively. The calibration curves were linear for a concentration range of 12.5-1500 ng/mL for propafenone and 2-500 ng/mL for 5-OHP and NDPP (r > 0.999). CVs in the intraday assays were 1.0-3.8% for propafenone, 0.6-2.0% for 5-OHP and 0.6-1.7% for NDPP. CVs in interday assays were 1.3-7.7% for propafenone, 1.1-6.5% for 5-OHP and 5.4-8.0% for NDPP. The present HPLC method can be used to assess the disposition of propafenone and its metabolites for pharmacokinetic studies and therapeutic drug monitoring of propafenone.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Propafenona/sangue , Adulto , Idoso , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Propafenona/isolamento & purificação , Propafenona/metabolismo , Propafenona/farmacocinética , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
PURPOSE: The efficacy and safety of indomethacin (IM) oral spray (OS) as a pain control therapy for oropharyngeal mucositis due to anticancer chemo- and radiotherapy were assessed in patients with head and neck carcinomas and haematological tumours. METHOD: We observed 35 patients (male/female, 20/15; 53 ± 17 years) with oropharyngeal mucositis who were treated with IM-OS preparation for pain relief at University of Tsukuba Hospital, Japan. Analgesic effects were assessed using the six-grade face scale for pain in 28 patients at the start of IM oral spray treatment. Systemic exposure was assessed by determining urinary excretions of IM in seven patients. RESULTS: Pain relief was achieved in 26 (93%) patients at 25 (5-60) min after applying the IM-OS preparation (15.6 ± 3.4 µg/kg) and analgesic effects were maintained for 120 (10-360) min. The pain was significantly decreased after using the spray (3.6 ± 0.7 vs. 2.4 ± 0.9, p < 0.01). Moreover, urinary IM excretion rates after applying the IM spray preparation were 1.8 ± 0.8% of the IM oral spray dose (130.5 ± 77.7 µg/kg/day), which was markedly lower than that following oral administration of IM (60%). No adverse events were observed following application of the spray. CONCLUSIONS: The present IM spray is an effective and safe preparation for pain relief and can be used as an alternative therapeutic option for oropharyngeal mucositis in cancer patients.
Assuntos
Neoplasias de Cabeça e Pescoço/terapia , Indometacina/administração & dosagem , Sprays Orais , Manejo da Dor/métodos , Dor/tratamento farmacológico , Faringite/tratamento farmacológico , Estomatite/tratamento farmacológico , Adulto , Idoso , Antineoplásicos/uso terapêutico , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/tratamento farmacológico , Feminino , Neoplasias Hematológicas/terapia , Humanos , Indometacina/efeitos adversos , Japão , Masculino , Pessoa de Meia-Idade , Orofaringe/efeitos dos fármacos , Orofaringe/patologia , Orofaringe/efeitos da radiação , Dor/etiologia , Faringite/etiologia , Lesões por Radiação/complicações , Lesões por Radiação/tratamento farmacológico , Estomatite/etiologiaRESUMO
The aim of this study was to examine the effect of food thickener on the pharmacodynamics of mitiglinide (MGN), a drug belonging to a class of rapid-acting insulin secretagogues. First, MGN tablets were coated by immersion in a xanthan gum-based food-thickening agent. This treatment was shown to delay disintegration rates of MGN tablets in vitro. The pharmacodynamics of MGN after ingestion of a single oral dose of an MGN tablet, with or without food thickener immersion, were then examined in an open-label crossover study comprising 5 healthy participants. It was observed that after administration of 75 g of oral glucose, the area under the blood glucose concentration-time curve was larger for treatment with MGN tablets that had been immersed in the food thickener than for nonimmersed tablets. The maximum blood glucose level was also higher in treatments with MGN tablets that had been immersed in food thickener. The extended time of higher glucose levels associated with thickener-immersed MGN tablets given to human volunteers may be associated with the reduced disintegration rates of immersed MGN tablets as observed in the in vitro experiment. Overall, our study suggests that commercially available food thickeners influence the pharmacodynamics of MGN and that their use should therefore be carefully assessed and monitored in certain clinical situations.
Assuntos
Glicemia/análise , Aditivos Alimentares/farmacologia , Hipoglicemiantes/uso terapêutico , Isoindóis/uso terapêutico , Adulto , Ingestão de Alimentos/fisiologia , Feminino , Humanos , Hipoglicemiantes/farmacologia , Isoindóis/farmacologia , Masculino , Pessoa de Meia-Idade , Período Pós-Prandial/fisiologiaRESUMO
The present study examined the dissolution of magnesium oxide (MgO) from MgO tablets placed in a food thickening agent (food thickener) and its effects on laxative activity. We prepared mixtures of MgO tablets suspended in an aqueous suspension and food thickeners in order to evaluate the dissolution of MgO. The results of the dissolution tests revealed that agar-based food thickeners did not affect the MgO dissolution. In contrast, some xanthan gum-based food-thickener products show dissolution rates with certain mixtures containing disintegrated MgO tablets suspended in a food thickener that decrease over time. However, other xanthan gum-based food-thickener products show dissolution rates that decrease immediately after mixing, regardless of the time they were allowed to stand. In order to investigate the laxative activity of MgO, we orally administered a mixture of MgO suspension and food thickener to mice and observed their bowel movements. The animal experiments showed that when agar-based food thickeners were used, the laxative activity of MgO was not affected, but it decreased when xanthan gum-based food thickeners were used.
Assuntos
Aditivos Alimentares/química , Laxantes/química , Laxantes/farmacologia , Óxido de Magnésio/química , Óxido de Magnésio/farmacologia , Polissacarídeos Bacterianos/química , Ágar/química , Animais , Masculino , Camundongos Endogâmicos ICR , Solubilidade , ComprimidosRESUMO
Stereoselective analyses of flecainide enantiomers were performed using reversed-phase high-performance liquid chromatography (HPLC) equipped with a polysaccharide-based chiral column (Chiralpak AS-RH) and fluorescence detector. Excitation and emission wavelengths were set at 300 and 370 nm, respectively. Flecainide enantiomers in serum and urine were extracted using diethyl ether. The mobile phase solution, comprising 0.1 m potassium hexafluorophosphate and acetonitrile (65:35, v/v), was pumped at a flow rate of 0.5 mL/min. The recoveries of flecainide enantiomers were greater than 94%, with the coefficients of variation (CVs) <6%. The calibration curves of flecainide enantiomers in serum and urine were linear in the concentration range 5-500 ng/mL and 0.75-15 µg/mL (r > 0.999), respectively. CVs in intra-day and inter-day assays were 1.8-5.8 and 3.4-7.5%, respectively. In a pharmacokinetic study, the ratios of (S)- to (R)-flecainide (S/R ratio) in the area under the curve and the amount of flecainide enantiomers excreted in urine were lower in a subject carrying CYP2D6*10/*10 than in subjects carrying CYP2D6*1/*2. The S/R ratio of trough serum flecainide concentration ranged from 0.79 to 1.16 in patients receiving oral flecainide. The present HPLC method can be used to assess hepatic flecainide metabolism in a pharmacokinetic study and therapeutic drug monitoring.
Assuntos
Cromatografia de Fase Reversa/métodos , Citocromo P-450 CYP2D6/metabolismo , Flecainida , Adulto , Feminino , Flecainida/sangue , Flecainida/química , Flecainida/urina , Humanos , Modelos Lineares , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , EstereoisomerismoRESUMO
OBJECTIVE: An increased slowing of cardiac conduction induced by sodium channel blockers is remarkably observed in carriers of an Asian-specific promoter haplotype [haplotype B (HapB)] of the cardiac sodium channel gene (SCN5A). We investigated the effect of HapB on the therapeutic range for serum flecainide concentration in Asian patients. PATIENTS AND METHODS: We examined the serum concentration and antiarrhythmic efficacy of flecainide, together with the SCN5A promoter haplotype, in 146 patients with supraventricular tachyarrhythmias. Trough serum flecainide concentrations were determined by HPLC. The antiarrhythmic efficacy of flecainide was assessed for at least 2 months through examination of symptomatology, ECG, and Holter monitoring. RESULTS: The serum flecainide concentration did not differ between the wild-type HapA homozygotes and HapB carriers under treatment with the usual dose. A genetic difference in the antiarrhythmic efficacy of flecainide was observed between the HapA homozygotes and HapB carriers at serum flecainide concentrations less than 300 ng/ml (42.9 vs. 68.8%; P=0.022). PR prolongation and QRS widening were observed more commonly among the HapB carriers with serum flecainide concentrations of at least 300 ng/ml than in the HapA homozygotes (PR, 210 ± 25 vs. 195 ± 25 ms; P=0.036; and QRS, 112 ± 10 vs. 105 ± 9 ms; P=0.030). CONCLUSION: These findings suggest that the therapeutic range for serum flecainide concentration is lower in HapB carriers than in HapA homozygotes.
Assuntos
Antiarrítmicos/sangue , Povo Asiático , Flecainida/sangue , Haplótipos , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Regiões Promotoras Genéticas , Idoso , Antiarrítmicos/farmacologia , Antiarrítmicos/uso terapêutico , Feminino , Flecainida/farmacologia , Flecainida/uso terapêutico , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Taquicardia Supraventricular/tratamento farmacológico , Taquicardia Supraventricular/genéticaRESUMO
The effects of solute carrier family 29 member 1 (SLC29A1) single nucleotide polymorphism (SNP), rs6932345 and rs747199, on SLC29A1 mRNA expression were examined. The expression levels of SLC29A1 mRNA in peripheral blood mononuclear cells (PBMCs) isolated from 46 healthy subjects (28 males and 18 females) was compared between wild-type and mutant carriers. The mRNA levels in the rs6932345 wild-type (AA genotype) was 1.71 times that in the mutation carriers (AC/CC genotype) (p<0.05). Similar results were observed for rs747199, because rs747199 was linked with rs6932345 at a frequency of 84.8%. It was confirmed that wild-type for rs6932345 and rs747199 showed higher SLC29A1 mRNA expression in PBMCs.
Assuntos
Transportador Equilibrativo 1 de Nucleosídeo/genética , Leucócitos Mononucleares/metabolismo , Povo Asiático/genética , Feminino , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , RNA Mensageiro/metabolismoRESUMO
Our aim was to determine whether metabolic clearance, renal clearance, or both elimination pathways contribute to ethnic differences in tizanidine clearance, which is ~ 2-fold higher in Caucasians than in Asians. The pharmacokinetic parameters of tizanidine in 9 healthy male Japanese subjects were compared with those of Caucasians in previous studies. Metabolic clearance of tizanidine was lower in Japanese than in Caucasian subjects (5.9 vs. 8.1 - 10.9 l/h/kg), although renal clearances were similar (0.040 vs. 0.047 - 0.055 l/h/kg). The results suggest that ethnic differences in tizanidine clearance are due to differences in metabolic clearance.
Assuntos
Clonidina/análogos & derivados , Adulto , Povo Asiático , Clonidina/farmacocinética , Citocromo P-450 CYP1A2/fisiologia , Humanos , Masculino , Taxa de Depuração Metabólica , População BrancaRESUMO
OBJECTIVE: To investigate the association between age-related decline in flecainide clearance and CYP2D6 genotype, we conducted a population pharmacokinetic analysis of flecainide using routine therapeutic drug monitoring data. METHODS: Population pharmacokinetic analysis was performed on retrospective data from 163 genotyped patients treated with oral flecainide for supraventricular tachyarrhythmias. The CYP2D6 genotype was categorized as CYP2D6 homozygous extensive metabolizers (hom-EMs; n=57), heterozygous extensive metabolizers (het-EMs; n=79), and intermediate metabolizers and poor metabolizers (IMs/PMs; n=27). RESULTS: Population pharmacokinetic analysis revealed that estimated glomerular filtration rate, body weight, female sex, and aging were important factors for estimating flecainide clearance. The metabolic clearance was decreased age dependently in a curvilinear fashion, where the lower clearance was observed in greater than 60 years for het-EMs and greater than 55 years for IMs/PMs. The reduction in metabolic clearance in elderly (70 years) patients compared with middle-aged (52 years) patients was different among the CYP2D6 genotype groups: 22.1 and 49.5% in CYP2D6 het-EMs and IMs/PMs, respectively, and no change in hom-EMs. A 11.4% reduction in estimated glomerular filtration rate in elderly patients compared with middle-aged patients corresponded to 6.1% decline in flecainide clearance. Overall, the age-related decline in flecainide clearance was 6.1% in hom-EMs, 16.3% in het-EMs, and 28.9% in IMs/PMs groups. CONCLUSION: This study suggests that CYP2D6 genotype is a determinant factor of age-related decline in flecainide clearance.
Assuntos
Antiarrítmicos/farmacocinética , Citocromo P-450 CYP2D6/genética , Flecainida/farmacocinética , Genótipo , Idoso , Antiarrítmicos/uso terapêutico , Citocromo P-450 CYP2D6/metabolismo , Monitoramento de Medicamentos , Feminino , Flecainida/uso terapêutico , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Farmacogenética , Estudos RetrospectivosAssuntos
Antipsicóticos/efeitos adversos , Aripiprazol/efeitos adversos , Leucopenia/sangue , Fumarato de Quetiapina/efeitos adversos , Antipsicóticos/administração & dosagem , Aripiprazol/administração & dosagem , Quimioterapia Combinada/efeitos adversos , Humanos , Leucopenia/induzido quimicamente , Fumarato de Quetiapina/administração & dosagemRESUMO
We developed a simple assay method for the determination of serum and urine norfloxacin and enoxacin using reversed-phase high-performance liquid chromatography and perchloric acid precipitation for sample pre-treatment. Optimized conditions can permit detection of norfloxacin and enoxacin in the same chromatogram, so either compound can be used as an internal standard for another determinant. Supernatants of the precipitated samples were analyzed by the octadecylsilyl silica-gel column under ambient temperature and an ultraviolet wavelength of 272 nm. A mobile phase solvent consisting of 20 mm sodium dihydrogenphosphate (pH 3.0) and acetonitrile (85:15, v/v) was pumped at a flow rate of 1.0 mL/min. The calibration curves for norfloxacin and enoxacin at a concentration of 62.5-1000 ng/mL for serum and 250-4000 ng/mL for urine were linear (r > 0.9997). The recoveries of norfloxacin and enoxacin from serum and urine were >94% with the coefficient of variations (CV) <5%. The CVs for intra- and inter-day assay of norfloxacin and enoxacin were <4.2 and <5.5%, respectively. This method can be applied to the pharmacokinetic study of norfloxacin and enoxacin after repeated administration to assess changes in CYP1A2 activity in healthy subjects.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Inibidores do Citocromo P-450 CYP1A2 , Enoxacino/farmacocinética , Norfloxacino/farmacocinética , Adulto , Cafeína/farmacocinética , Cafeína/urina , Cromatografia de Fase Reversa , Citocromo P-450 CYP1A2 , Enoxacino/sangue , Enoxacino/urina , Humanos , Masculino , Norfloxacino/sangue , Norfloxacino/urina , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Teofilina/farmacocinética , Teofilina/urinaRESUMO
Lithium carbonate is used to increase white blood cell counts as a means of counteracting leukopenia caused by the administration of antipsychotic drugs. To evaluate the effect of antipsychotics on the leukocyte-enhancing effect of lithium, we compared white blood cell counts, serum lithium levels, and lithium dosage in patients receiving antipsychotics and lithium in combination and patients receiving lithium alone. Chlorpromazine equivalent values were used as an indicator of the antipsychotic dose. Lithium serum levels were measured in 41 hospitalized patients. The lithium dose in the combination group (median, 800 mg) was significantly higher than that in group receiving only lithium (median, 400 mg) (P = 0.03). The lithium doses in the combination group receiving ≥1000 mg chlorpromazine equivalents (overdosing; median lithium dose 800 mg) and the combination group treated with 600-999 mg chlorpromazine equivalents (high dosing; median lithium dose 800 mg) were significantly higher than the group that was not treated with antipsychotic medication, with median lithium dose 400 mg (P < 0.05).There were no significant differences in the white blood cell counts and serum lithium levels. Because of the large variety of antipsychotic drugs used in combination with lithium and the various doses used, it was difficult to evaluate the effects of lithium, with or without antipsychotic administration, on leukocyte count enhancement. We are planning to study a larger number of patients and, since renal function could not be assessed in this study, we will also focus on renal function, including urine output.
Assuntos
Antipsicóticos , Leucopenia , Antipsicóticos/uso terapêutico , Humanos , Contagem de Leucócitos , Leucopenia/induzido quimicamente , Leucopenia/tratamento farmacológico , Lítio/efeitos adversos , Carbonato de Lítio/efeitos adversosRESUMO
Aim: The study aims to investigate the clinical implication of nonfunctional poor metabolizer (PM) alleles and intermediate metabolizer (IM) alleles of CYP2D6, including the CYP2D6*10 allele which shows substrate-dependent decrease in enzymatic activity, in antiarrhythmic therapy using propafenone. Materials & methods: We examined serum propafenone concentrations and metabolic ratio, which was expressed as serum concentrations of propafenone to 5-hydroxypropafenone, in 66 Japanese patients with tachyarrhythmias. Results: The peak propafenone concentration and metabolic ratio in CYP2D6 PM allele carriers were higher than those in extensive metabolizer (EM)/EM, EM/IM and IM/IM genotype groups. Conclusion: Results suggest that CYP2D6 PM alleles affect peak propafenone concentration, but the CYP2D6 IM allele CYP2D6*10 has no clinical implication in propafenone dosing.
Assuntos
Antiarrítmicos/farmacocinética , Citocromo P-450 CYP2D6/genética , Propafenona/farmacocinética , Idoso , Alelos , Antiarrítmicos/uso terapêutico , Arritmias Cardíacas/tratamento farmacológico , Biotransformação , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Polimorfismo Genético , Propafenona/análogos & derivados , Propafenona/sangue , Propafenona/uso terapêuticoRESUMO
AIMS: The aim of this study was to clarify the effects of CYP2D6 genotype on age-related change in flecainide metabolism in patients with supraventricular tachyarrhythmias. An in vitro study using microsomes was performed to identify other CYPs responsible for age-related change in flecainide metabolism. METHODS: The study population comprised 111 genotyped patients: CYP2D6-homozygous extensive metabolizers (hom-EMs, n= 34), heterozygous EMs (het-EMs, n= 56), and intermediate and poor metabolizers (IMs/PMs, n= 21). Serum concentrations of flecainide and its metabolites [m-O-dealkylated flecainide (MODF) and m-O-dealkylated lactam of flecainide] were determined by use of a high-performance liquid chromatography. Metabolic ratio (MR) was expressed as serum concentrations of flecainide to its metabolites. In vitro formation of MODF was examined in human liver microsomes and cDNA-expressed CYP isoforms. RESULTS: MR was higher in elderly patients (> or =70 years) than in middle-aged patients (<70 years). The increase of MR in elderly patients differed among CYP2D6 genotypes: 1.6-fold in het-EMs [4.3, 95% confidence interval (CI) 2.8, 5.7 vs. 2.7, 95% CI 2.3, 3.1, P < 0.05], 1.5-fold in IMs/PMs (6.0, 95% CI 4.5, 7.6 vs. 4.1, 95% CI 2.9, 5.4, P < 0.05), and no change in hom-EMs. The in vitro study using microsomes revealed that both CYP2D6 and CYP1A2 were involved in the formation of MODF. MODF formation in CYP2D6 PM microsomes increased as CYP1A2 activity increased. CONCLUSIONS: The results suggest that patients with poor CYP2D6-mediated metabolism (het-EMs and IMs/PMs) showed age-related reduction in flecainide metabolism because metabolism was taken over by CYP1A2, whose activity decreases with age.
Assuntos
Antiarrítmicos/uso terapêutico , Citocromo P-450 CYP1A2/genética , Citocromo P-450 CYP2D6/genética , Flecainida/metabolismo , Taquicardia Supraventricular/tratamento farmacológico , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Citocromo P-450 CYP1A2/metabolismo , Citocromo P-450 CYP2D6/metabolismo , Feminino , Flecainida/uso terapêutico , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
AIM: To assess whether or not co-administration of proton pump inhibitors (PPIs) is a risk factor for delayed elimination of plasma methotrexate (MTX) in high-dose MTX (HDMTX) therapy for malignant diseases. METHODS: To assess the effects of PPI co-administration on elimination of plasma MTX, we examined plasma MTX concentration data on 171 cycles of HDMTX therapy performed in 74 patients. We performed multiple logistic regression analysis to evaluate PPI co-administration as a risk factor. Inhibitory potencies of omeprazole, lansoprazole, rabeprazole and pantoprazole on MTX transport via breast cancer resistance protein (BCRP, ABCG2) were also investigated in an in vitro study using membrane vesicles expressing human BCRP. RESULTS: We identified co-administration of PPIs as a risk factor for delayed elimination (odds ratio 2.65, 95% confidence interval 1.03, 6.82) as well as renal and liver dysfunction. All four PPIs inhibited BCRP-mediated transport of MTX, with half-maximal inhibitory concentrations of 5.5-17.6 microM--considerably higher than the unbound plasma concentrations of the PPIs. CONCLUSIONS: Our results support previous findings suggesting that PPI co-administration is associated with delayed elimination of plasma MTX in patients with HDMTX therapy. This drug interaction, however, cannot be explained solely by the inhibitory effects of PPIs on BCRP-mediated MTX transport.
Assuntos
Antimetabólitos Antineoplásicos/metabolismo , Metotrexato/metabolismo , Neoplasias/tratamento farmacológico , Inibidores da Bomba de Prótons/farmacologia , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/metabolismo , Adolescente , Adulto , Idoso , Antimetabólitos Antineoplásicos/administração & dosagem , Transporte Biológico/efeitos dos fármacos , Interações Medicamentosas , Feminino , Humanos , Modelos Logísticos , Masculino , Metotrexato/administração & dosagem , Pessoa de Meia-Idade , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Inibidores da Bomba de Prótons/farmacocinética , Adulto JovemRESUMO
The effects of intracellular ribavirin on morphology and redistribution of phosphatidylserine (PS) in human erythrocytes were examined. Erythrocytes were incubated with 1 mM ribavirin in the presence/absence of dipyridamole, an inhibitor of es-type nucleoside transporter. Intracellular ribavirin was accumulated in erythrocytes with the concentration of 1361 muM, which corresponds to the blood level in patients receiving ribavirin. Dipyridamole reduced ribavirin accumulation by 40.7% (807 muM) via inhibiting es-type nucleoside transporter on erythrocytes. Morphological transformation into echinocytic form was observed in 86.4% of the erythrocytes treated with ribavirin. Dipyridamole pre-treatment decreased the morphological change to 20.0%. Ribavirin increased the PS-exposing cells compared with control (2.15% vs. 0.87%). PS-exposing cells were also decreased by inhibiting ribavirin accumulation with dipyridamole (0.62%). The results suggest that intracellular ribavirin induces morphological change and PS exposure in erythrocytes and accelerates erythrophagocytosis in the reticuloendothelial system.
Assuntos
Antivirais/farmacologia , Eritrócitos/efeitos dos fármacos , Fosfatidilserinas/farmacologia , Ribavirina/farmacologia , Cromatografia Líquida de Alta Pressão , Citometria de Fluxo , HumanosRESUMO
We developed a sensitive high performance liquid chromatography (HPLC) method for determining CYP2D6 mRNA in peripheral blood leukocytes (PBL) by using competitive reverse transcriptase polymerase chain reaction (RT-PCR). The method is specific, reproducible, and sensitive enough to quantify the absolute amount of low and high abundant CYP2D6 mRNA. The native CYP2D6 transcript and the internal standard, a CYP2D6 deletion RNA, were amplified with similar efficiency in RT-PCR. The PCR products were separated as the corresponding peaks in optimized HPLC. The coefficients of variation for competitive RT-PCR and HPLC determination were 1.5-6.5% and 0.6-2.4%, respectively, showing high reproducibility and reliability. This approach could also be applicable to the quantification of mRNA expressing on various tissues, including PBL, of which the expression levels were so low that they were hard to determine by existing agarose gel electrophoresis methods.
Assuntos
Citocromo P-450 CYP2D6/genética , Leucócitos/metabolismo , RNA Mensageiro/sangue , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Cromatografia Líquida de Alta Pressão , Humanos , RNA Mensageiro/genética , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
High dose glucocorticoids (GC) are commonly used for the treatment of autoimmune diseases. The frequencies, occurrence day and dose-dependency for side effects may be different among the events such as diabetes mellitus, hyperlipidemia, infectious disease, osteoporosis, and peptic ulcer. We investigated GC-induced side effects in 68 patients treated with GC for autoimmune diseases. Initial dose of GC (prednisolone equivalent) was 0.67+/-0.35 mg/kg/d. Hypercholesterolemia (66%), hypertension (62%), insomnia (50%), hypertriglyceridemia (44%), excessive appetite (38%), hyperglycemia (18%), digestive symptom (16%), moon-shaped face (13%) and oral candidiasis (12%) were observed in 63 patients treated with GC. Hypercholesterolemia, excessive appetite, digestive symptom, moon-shaped face, and oral candidiasis were associated with the initial dose of prednisolone greater than 0.80 mg/kg/d. Insomnia [median 6 days (range 1-88)], excessive appetite [7 days (2-57)], hypertension [8 days (1-37)], digestive symptom [15 days (1-87)] and hypercholesterolemia [19 days (3-77)] were observed early after 6-19 days starting GC. On the other hand, hypertriglyceridemia [33 days (2-131)], oral candidiasis [35 days (7-52)] and hyperglycemia [60 days (4-134)] were developed after 33-60 days starting GC. Since the frequencies, dose-dependency and occurrence day were different among the side effects of GC, medical staffs including physicians and pharmacists should pay attention such features of the events in the treatment of autoimmune diseases.
Assuntos
Doenças Autoimunes/tratamento farmacológico , Candidíase Bucal/induzido quimicamente , Glucocorticoides/efeitos adversos , Hipercolesterolemia/induzido quimicamente , Hiperglicemia/induzido quimicamente , Hipertensão/induzido quimicamente , Prednisolona/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Apetite/efeitos dos fármacos , Candidíase Bucal/epidemiologia , Relação Dose-Resposta a Droga , Feminino , Glucocorticoides/administração & dosagem , Humanos , Hipercolesterolemia/epidemiologia , Hiperglicemia/epidemiologia , Hipertensão/epidemiologia , Hipertrigliceridemia/induzido quimicamente , Hipertrigliceridemia/epidemiologia , Masculino , Pessoa de Meia-Idade , Prednisolona/administração & dosagem , Distúrbios do Início e da Manutenção do Sono/induzido quimicamente , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Adulto JovemRESUMO
In this study, we first performed a disintegration test of the voglibose orally disintegrating (V-OD) tablet immersed in jelly-wafer (JW, V-ODims/jw) for 10 min and compared it with the disintegration time of V-OD that was not immersed in JW. We then orally administered the V-ODims/jw tablet to 7 healthy adults and compared the shift in blood glucose levels (BGLs), after loading with a sucrose solution (Suc-sol, 100 g/150 mL), with that after administration of the non-immersed V-OD tablet. The disintegration time of V-ODims/jw tablet was shorter than that of V-OD. When administered to healthy adults, the BGL after loading with Suc-sol was higher with V-ODims/jw tablet administration than with V-OD tablet. We predict that the expression of the efficacy of voglibose is reduced as a result of the interaction between voglibose and the polysaccharide, xanthan gum (XG), since it is a common additive in JW. This study shows that deglutition aids with additives that do not affect pharmacokinetics must be carefully selected for administering along with pharmaceuticals, because of a suggested possibility that the interaction between these pharmaceuticals and the additives in the deglutition aids weaken the drug efficacy. A more careful selection of deglutition aids from the wide selection of medication is especially important when administered to patients who use these deglutition aids often, such as elderly individuals or individuals with a deglutition disorder.