RESUMO
Saliva is widely used for clinical and laboratory analysis. This study proposed to use DNA extracted from saliva for genotyping and pharmacokinetics of piroxicam. A fast and efficient genotyping method was used to determine relevant allelic variants of CYP2C9 (*2 and *3), since genetic factors can influence in non-steroidal anti-inflammatory drugs (NSAIDs) metabolization. DNA Extract All Reagents Kit® was used for DNA extraction and genotyping was performed using TaqMan® GTXpress™ Master Mix, SNP genotyping assays and a Viia7 Real-Time PCR system. Volunteers performed sequential collections of saliva samples before and after taking a single dose of piroxicam (0.25 to 72 h) which were used for pharmacokinetics assays. Piroxicam concentrations were analyzed using LC-MS/MS. Sixty-six percent of volunteers were ancestral homozygous (CYP2C9*1/*1), and 34% showed one or both polymorphisms. Of these 34%, 22 individuals showed CYP2C9*2 polymorphism, 8 CYP2C9*3, and 4 CYP2C9*2/*3. Piroxicam pharmacokinetics were performed in 5 subjects. Areas under the curve (AUC0-t(h*ng/mL)) for CYP2C9*1/*1, *1/*2 and *1/*3 were, respectively, 194.33±70.93, 166 and 303. Maximum concentrations (Cmax(ng/mL)) for these genotypes were respectively 6.46±2.56, 4.3 and 10.2. Saliva sampling was a very effective matrix for both pharmacogenetic and pharmacokinetic tests, ensuring the speed of the procedure and the well-being and agreement of the participants. Once having the knowledge about the slow and fast metabolizers, it is possible to make an adequate prescription in order to avoid the adverse effects of the medication and to guarantee greater analgesic comfort to the patients respectively.
Assuntos
Farmacogenética , Saliva , Cromatografia Líquida , Citocromo P-450 CYP2C9/genética , Prescrições de Medicamentos , Humanos , Espectrometria de Massas em TandemRESUMO
Abstract Saliva is widely used for clinical and laboratory analysis. This study proposed to use DNA extracted from saliva for genotyping and pharmacokinetics of piroxicam. A fast and efficient genotyping method was used to determine relevant allelic variants of CYP2C9 (*2 and *3), since genetic factors can influence in non-steroidal anti-inflammatory drugs (NSAIDs) metabolization. DNA Extract All Reagents Kit® was used for DNA extraction and genotyping was performed using TaqMan® GTXpress™ Master Mix, SNP genotyping assays and a Viia7 Real-Time PCR system. Volunteers performed sequential collections of saliva samples before and after taking a single dose of piroxicam (0.25 to 72 h) which were used for pharmacokinetics assays. Piroxicam concentrations were analyzed using LC-MS/MS. Sixty-six percent of volunteers were ancestral homozygous (CYP2C9*1/*1), and 34% showed one or both polymorphisms. Of these 34%, 22 individuals showed CYP2C9*2 polymorphism, 8 CYP2C9*3, and 4 CYP2C9*2/*3. Piroxicam pharmacokinetics were performed in 5 subjects. Areas under the curve (AUC0-t(h*ng/mL)) for CYP2C9*1/*1, *1/*2 and *1/*3 were, respectively, 194.33±70.93, 166 and 303. Maximum concentrations (Cmax(ng/mL)) for these genotypes were respectively 6.46±2.56, 4.3 and 10.2. Saliva sampling was a very effective matrix for both pharmacogenetic and pharmacokinetic tests, ensuring the speed of the procedure and the well-being and agreement of the participants. Once having the knowledge about the slow and fast metabolizers, it is possible to make an adequate prescription in order to avoid the adverse effects of the medication and to guarantee greater analgesic comfort to the patients respectively.
Resumo Saliva é amplamente utilizada para análises clínicas e laboratoriais. Este estudo propôs o uso de DNA extraído da saliva para genotipagem e farmacocinética do piroxicam. Um método de genotipagem rápido e eficiente foi usado para determinar as variantes alélicas clinicamente relevantes de CYP2C9 (* 2 e * 3), uma vez que fatores genéticos podem influenciar nas respostas metabólicas individuais a medicamentos como anti-inflamatórios não esteroides (AINEs). DNA Extract All Reagents Kit® foi usado para extração de DNA e a genotipagem foi realizada usando TaqMan® GTXpress ™ Master Mix, ensaios de genotipagem SNP e um sistema Viia7 Real-Time PCR. Os voluntários realizaram coletas sequenciais de amostras de saliva antes e após a ingestão de uma única dose de piroxicam (0,25 a 72 h) que foram utilizadas para ensaios farmacocinéticos. As concentrações de piroxicam foram analisadas usando LC - MS / MS. Sessenta e seis por cento dos voluntários eram homozigotos ancestrais (CYP2C9 * 1 / * 1) e 34% apresentaram um ou ambos os polimorfismos. Destes 34%, 22 indivíduos apresentaram polimorfismo CYP2C9 * 2, 8 CYP2C9 * 3 e 4 CYP2C9 * 2 / * 3. A farmacocinética do piroxicam foi realizada em 5 indivíduos. As áreas sob a curva (AUC0-t (h * ng / mL)) para CYP2C9 * 1 / * 1, * 1 / * 2 e * 1 / * 3 foram, respectivamente, 194,33±70,93, 166 e 303. Concentrações máximas (Cmax (ng / mL)) para esses genótipos foram, respectivamente, 6,46±2,56, 4,3 e 10,2. A amostra de saliva foi uma matriz muito eficaz tanto para os testes farmacogenéticos quanto para os farmacocinéticos, garantindo a agilidade do procedimento e o bem-estar e concordância dos participantes. Com o conhecimento dos metabolizadores lentos e rápidos, é possível fazer uma prescrição adequada para evitar os efeitos adversos da medicação e garantir maior conforto analgésico aos pacientes respectivamente.
Assuntos
Humanos , Farmacogenética , Saliva , Prescrições de Medicamentos , Cromatografia Líquida , Espectrometria de Massas em Tandem , Citocromo P-450 CYP2C9/genéticaRESUMO
Saliva sampling used to quantify piroxicam and 5'-hydroxypiroxicam is a noninvasive and painless method when compared to sequential blood sampling. For that, a rapid, selective and sensitive liquid chromatography-tandem mass spectrometric method for simultaneous determination of piroxicam and 5'-hydroxypiroxicam in saliva and human plasma was developed and validated. Piroxicam and its major metabolite were separated using a LiChroCART 125-4 RP Select-B Sorbent C18 column using a mixture of methanol and 2% phosphoric acid (pH 2.7) (70:30, v/v) for the mobile phase with a flow injection of 1mL/min. The run time was 4min. Volunteers had saliva and blood sampled before, 1, 2, 3, 4, 5, 6, 8, 11, 24, 48 and 72h after taking a 20mg oral dose of piroxicam. The pharmacokinetic parameters of piroxicam in plasma samples were as follows: AUC0-72 (64819hng/mL), predicted clearance (0.2L/h), distribution volume (14.8L), elimination half-life (50.7h) and saliva/plasma concentration ratio (0.003). The estimation of all pharmacokinetic parameters for 5'-hydroxypiroxicam would require collections beyond 72h; however, it was possible to quantify the mean maximum concentration (133ng/mL), time to peak concentration (53.6h), mean AUC0-72 (6213hng/mL), predicted clearance (110.3L/h) and saliva/plasma concentration ratio (0.04). The developed methods proved effective and sensitive for determining the lower quantification limit of piroxicam in plasma (6.1ng/mL) and saliva (0.15ng/mL) and of 5'-hydroxypiroxicam in plasma (1.2ng/mL) and saliva (0.15ng/mL).