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- A review of current bioanalytical approaches in sample pretreatment techniques for the determination of antidepressants in biological specimensPublication . Soares, Sofia; Barroso, Mário; Gallardo, EugeniaAntidepressants are a class of compounds widely used in clinical settings for the treatment of several diseases. In the last years there has been a considerable increase in their consumption, representing an important public health issue in several countries. Because they are substances with narrow therapeutic windows, and since they are capable of interacting with other classes of compounds, monitoring of these compounds is of relevance, minimizing the risk of medical interactions as well as side and toxic effects. In addition, understanding the extent of their use, their detection through routine toxicology tests and development of new methods for detection and monitoring is of extreme importance concerning public health, patient well-being, and implications in clinical and forensic situations. The main objective of this work is to perform a critical review on the biological samples used in the detection and quantification of antidepressants with special focus on the techniques for sample preparation.
- The potential of dried saliva spots for antidepressant drugs monitoringPublication . Soares, Sofia; Rosado, Tiago; Barroso, Mário; Gallardo, EugeniaIntroduction: Portugal has one of the highest rates of mental illness in Europe, and the consumption of antidepressants amongst its population has doubled between the years 2013 and 2016. Approximately 30 million packs of medication are prescribed and dispensed annually in this country to treat major depressive disorders. Therapeutic Drug Monitoring (TDM) is a practice established for a small number of drugs, for which there is a direct relationship between concentration and pharmacological effect at the site of action. Commonly, TDM involves measuring drug concentrations in serum, plasma or blood, being complemented with clinical observation measures to assess patient’s condition, support the individualization of therapy, detect changes in the patient´s pathophysiological status or the modification of the drug pharmacokinetics, but also to assess adherence to therapy. Methodology: The present work describes a methodology with great potential for TDM purposes, allowing the determination of antidepressants (fluoxetine, venlafaxine, citalopram, sertraline, paroxetine and metabolites) using 100 μL of oral fluid with dried saliva spots (DSS) and analysis by gas chromatography-tandem mass spectrometry (GC-MS/MS). Results: For both sampling and extraction with DSS, several parameters were optimized using the statistical tool Design of Experiments (DoE), namely: drying and extraction times, extraction solvent and volume. The final optimized conditions were: 1 hour of drying, 1 mL of methanol and 5 minutes of extraction. The method was validated showing linearity within the adopted therapeutic ranges, with limits of detection and quantification between 10 and 100 ng/mL. All validation parameters were assayed according to the SWGTOX guidelines. Discussion: This is the first work that uses DSS to extract antidepressants from oral fluid samples, proving to be a sensitive, simple and fast alternative to conventional techniques and samples used in TDM (solid phase extraction based procedures and plasma samples). It also reveals potential to be routinely applied in TDM and forensic toxicology purposes, as it has been successfully applied to the analysis of authentic patient samples.
- Quantification of antidepressants in oral fluid and plasma samples using microextraction by packed sorbent and analysis by gas chromatography-tandem mass spectrometryPublication . Soares, Sofia; Rosado, Tiago; Barroso, Mário; Gallardo, EugeniaThe consumption of antidepressants is extremely significant as they are a class of medications widely used in the treatment of numerous disorders and are therefore considered a public health problem throughout the world. The aim of this work was to develop and optimize two methodologies for the determination of selected antidepressants and metabolites (fluoxetine, venlafaxine, O-desmethylvenlafaxine, citalopram, sertraline, paroxetine), in 250 µL of sample (oral fluid and plasma) using microextraction by packed sorbent (MEPS) as the extraction technique and gas chromatography coupled to tandem mass spectrometry (GC–MS/MS) for analysis. The two methods were fully validated considering the internationally accepted criteria for bioanalytical procedures, presenting linearity within the studied range, with limits of quantification between 10 and 100 ng/mL, coefficients of determination (R2) of at least 0.99 and precision and accuracy with acceptable values of coefficients of variation and relative errors for all antidepressants in study and for both specimens. Recoveries ranged between approximately 12 and 93 % for oral fluid samples and between approximately 28 and 101 % for plasma samples. To our best knowledge, the described methods are the first to be reported using MEPS and GC–MS/MS for the identification of antidepressants in oral fluid and plasma samples, proving to be sensitive, simple, fast and capable of being applied in routine clinical and forensic toxicology scenarios.
- Monitorização de antidepressivos: comparação de dois métodos de extração em amostras de fluido oralPublication . Soares, Sofia; Rosado, Tiago; Barroso, Mário; Gallardo, EugeniaO consumo de antidepressivos representa uma problemática mundial, apresentando Portugal uma das taxas de prevalência de doenças mentais mais elevadas da Europa1. A monitorização terapêutica é instituída para um pequeno número de fármacos para os quais existe uma relação direta entre a concentração e o efeito farmacológico. Este trabalho compara duas metodologias desenvolvidas para a determinação de antidepressivos (fluoxetina, venlafaxina, sertralina, citalopram, paroxetina e metabolitos) em amostras de fluido oral com recurso à cromatografia gasosa acoplada à espectrometria de massa em tandem. O primeiro método utiliza amostragem por dried saliva spots (DSS) como técnica de extração. O volume de amostra foi de 100 μL e o procedimento foi otimizado utilizando a ferramenta estatística Design of Experiments (DoE) para avaliação dos tempos de secagem e extração e do solvente e volume do solvente de extração. As recuperações variaram entre 13 e 46%2. A segunda metodologia implementa a microextração em seringa empacotada (MEPS), utilizando 250 μL de amostra. Esta técnica foi otimizada utilizando a ferramenta de DoE para avaliação do número de strokes no load da amostra, número de lavagens e número de eluições. As recuperações variaram entre 12 e 93%. Ambos os métodos foram validados seguindo diretrizes internacionais. Os limites de quantificação foram estabelecidos entre 10-100 ng/mL e o intervalo de linearidade variou entre 10-500 ng/mL para ambas as metodologias (dentro do intervalo terapêutico). Este trabalho é o primeiro a utilizar DSS e MEPS para determinação destes antidepressivos em fluido oral.
- Development and optimization of a new method to determine antidepressants in oral fluid by microextraction by packed sorbent and analysis by GC-MS/MSPublication . Soares, Sofia; Rosado, Tiago; Barroso, Mário; Gallardo, EugeniaBetween 2013 and 2016, the consumption of antidepressants doubled in Portugal, with around 30 million packages of medication for depression, anxiety and other mental health problems dispensed annually. This phenomenon has even given rise to several alerts, which was highlighted in the 2017 report of the National Program for Mental Health, as Portugal has one of the highest rates of mental illness in Europe1. Therapeutic drug monitoring is well established for a small number of drugs, namely for those where a direct relationship between concentration and pharmacological effect at the site of action exists, which in turn is predictably reflected in the response. Drug concentrations in the various biological fluids are used in conjunction with other clinical observation measures to assess the patient's condition, and further support the individualization of therapy. Within this group of drugs targeted for monitoring are antidepressants. In recent years, oral fluid has gained more and more importance in the field of therapeutic drug monitoring, as a non-invasive and painless alternative to traditionally sampled specimens (e.g. blood, plasma). MEPS is a miniaturized solid-phase extraction (SPE) and therefore has a great advantage in the reduced operating volumes and consequently lower amounts of sample and organic solvents are required. As a result, MEPS decreases the time required for extraction, clean-up and concentration of analytes. This is the first work that uses MEPS as sample preparation technique for the determination of antidepressants and metabolites in oral fluid samples (250 µL). The simple extraction procedure proved to be efficient, requiring only 250 µL of biological sample, making it an excellent alternative for the determination of these compounds in routine clinical and forensic toxicology laboratories and for therapeutic monitoring purposes.