Utilizing quantitative dried blood spot analysis to objectively assess adherence to cardiovascular pharmacotherapy among patients at Kenyatta National Hospital, Nairobi, Kenya.

The burden of cardiovascular disease (CVD) is rising in Kenya and non-adherence to cardiovascular pharmacotherapy is a growing global public health issue that leads to treatment failure, an increased risk of cardiac events and poor clinical outcomes. This study assessed adherence to selected cardiovascular therapy medications among CVD patients attending outpatient clinics at Kenyatta National Hospital, Kenya by determining drug concentration(s) in patient dried blood spot (DBS) samples. Patients who had been taking one or more of the five commonly prescribed CVD medications (amlodipine, atenolol, atorvastatin, losartan, and valsartan) for at least six months were enrolled. Each patient completed a short questionnaire about their medication history and then provided a finger-prick blood spot sample from which drug concentrations were determined by liquid chromatography-high resolution mass spectrometry analysis. Two hundred and thirty-nine patients (62.3% female) participated in the study. The median number of medications used by patients was 2 (IQR 75%-25% is 3-1). Less than half (117; 49.0%) of patients were adherent to their prescribed CVD pharmacotherapy. Binary regression analysis revealed a significant correlation between non-adherence and the number of medications in the treatment regimen (Odds Ratio (OR) 1.583; 95%CI: 0.949-2.639; P-value = 0.039) and that gender was not an independent predictor of medication adherence (OR 1.233; 95%CI: 0.730-2.083; P-value = 0.216). Valuable information about adherence to each medication in the patient's treatment regimen was obtained using quantitative DBS analysis showing that adherence to CVD medications was not uniform. DBS sampling, due its minimally invasive nature, convenience and ease of transport is a useful alternative matrix to monitor adherence to pharmacotherapies objectively, when combined with hyphenated mass spectrometry analytical techniques. This information can provide physicians with an evidence-based novel approach towards personalization and optimization of CVD pharmacotherapy and implementing interventions in the Kenyan population, thereby improving clinical outcomes.

Hyphenated mass spectrometry techniques for assessing medication adherence: advantages, challenges, clinical applications and future perspectives.

Nonadherence to prescribed pharmacotherapy is an understated public health problem globally and is costing many patients their chance to return to good health and healthcare systems billions. Clinicians need an accurate assessment of adherence to medications to aid the clinical decision-making process in the event of poor patient progress and to maximise the patient health outcomes from the drug therapies prescribed. An overview of indirect and direct methods used to measure medication adherence is presented, highlighting the potential for accurate measuring of drugs in biological samples using hyphenated mass spectrometry (MS) techniques to provide healthcare professionals with a reliable evidence base for clinical decision making. In this review we summarise published applications of hyphenated MS techniques for a diverse range of clinical areas demonstrating the rise in the use of such direct methods for assessing medication adherence. Although liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods using plasma, serum and urine samples are the most popular, in recent years increased attention has been given to liquid chromatography high-resolution mass spectrometry (LC-HRMS) methods and alternative biosample matrices including hair, saliva and blood microsamples. The advantages and challenges of using hyphenated MS techniques to address this healthcare problem are also discussed alongside future perspectives.

Quantitative screening of the pharmaceutical ingredient for the rapid identification of substandard and falsified medicines using reflectance infrared spectroscopy.

The World Health Organization suggests that approximately 10% of medicines worldwide are either falsified or substandard with higher figures in low and middle income countries. Such poor quality medicines can seriously harm patients and pose a threat to the economy worldwide. This study investigates attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy as a simple and rapid method for determination of drug content in tablet dosage forms. Paracetamol was used as the model pharmaceutical ingredient. Spectra of standard mixtures of paracetamol with different excipients formed the basis for multivariate PLS based quantitative analysis of simulated tablet content using different selected infrared absorbance bands. Calibration methods using ATR-FTIR were compared with the ATR-FTIR and conventional ultraviolet spectroscopic analyses of real tablet samples and showed that the paracetamol/microcrystalline cellulose mixtures gave optimum results for all spectral bands tested. The quantitative data for band 1524-1493cm-1 was linear (R2 ˃ 0.98; LOQ ≥ 10%w/w tablet). Global examples of paracetamol tablets were tested using this protocol and 12% of the tablet samples examined was identified as substandard. Each sample analysis was completed in just a few minutes. ATR-FTIR can therefore be used in the rapid screening of tablet formulations. The simplicity of the proposed method makes it appropriate for use in low and middle income countries where analytical facilities are not available.