Adherence to cardiovascular pharmacotherapy by patients in Iraq: A mixed methods assessment using quantitative dried blood spot analysis and the 8-item Morisky Medication Adherence Scale.

This study evaluated the adherence to prescribed cardiovascular therapy medications among cardiovascular disease patients attending clinics in Misan, Amara, Iraq. Mixed methods were used to assess medication adherence comprising the Arabic version of the eight-item Morisky Medication Adherence Scale (MMAS-8) and determination of drug concentrations in patient dried blood spot (DBS) samples by liquid chromatography-high resolution mass spectrometry. Three hundred and three Iraqi patients (median age 53 years, 50.5% female) who had been taking one or more of the nine commonly prescribed cardiovascular medications (amlodipine, atenolol, atorvastatin, bisoprolol, diltiazem, lisinopril, losartan, simvastatin and valsartan) for at least six months were enrolled. For each patient MMAS-8 scores were determined alongside drug concentrations in their dried blood spot samples. Results from the standardized questionnaire showed that adherence was 81.8% in comparison with 50.8% obtained using the laboratory-based microsample analysis. The agreement between the indirect (MMAS-8) and direct (DBS analysis) assessment approaches to assessing medication adherence showed significantly poor agreement (kappa = 0.28, P = 0.001). The indirect and direct assessment approaches showed no significant correlation between nonadherence to prescribed cardiovascular pharmacotherapy and age and gender, but were significantly associated with the number of medications in the patient's treatment regimen (MMAS-8: Odds Ratio (OR) 1.947, 95% CI, P = 0.001; DBS analysis: OR 2.164, 95% CI, P = 0.001). The MMAS-8 results highlighted reasons for nonadherence to prescribed cardiovascular pharmacotherapy in this patient population whilst the objective DBS analysis approach gave valuable information about nonadherence to each medication in the patient's treatment regimen. DBS sampling, due its minimally invasive nature, convenience and ease of transport is a useful alternative matrix to monitor adherence objectively in Iraq to cardiovascular pharmacotherapy. This information combined with MMAS-8 can provide clinicians with an evidence-based novel approach to implement intervention strategies to optimise and personalise cardiovascular pharmacotherapy in the Iraqi population and thereby improve patient health outcomes.

Dried blood spot analysis to assess medication adherence and to inform personalization of treatment.

Little research using dried blood spot samples to assess adherence to medication has been reported. The World Health Organisation estimates that only half of the patients in the developed world take their medication as prescribed. Additional costs to the healthcare provider include wasted medicines, avoidable additional hospital visits and non-optimum patient care. There is little evidence of information concerning medication adherence being made available to inform clinical decision making. In this article we explore the potential of the dried blood spot sample collection methodology as a means of identifying medication adherence to facilitate medicines optimization for a range of disparate diseases. Furthermore, the opportunity to personalize healthcare for different patients by assessing the clinically necessary therapeutic level of the relevant drugs is highlighted.

Facilitating pharmacokinetic studies in children: a new use of dried blood spots.

Pharmacokinetic data are used to develop dosing regimens for medicines. The dose regimens of many drugs administered to children have historically been based on pharmacokinetic data generated in adults. The 'adult' dose was simply adjusted to the child's body weight or surface area. This practice is potentially unsafe and not acceptable to drug regulatory agencies. Obtaining pharmacokinetic data in children is beset with ethical issues and technical challenges as pharmacokinetic studies require repeated measurement of drug levels in blood. Dried blood spot (DBS) samples used in conjunction with population pharmacokinetic modelling techniques is one potential method for performing pharmacokinetic studies in children. In this article, we review the DBS technique for performing pharmacokinetic studies and highlight issues that still need to be addressed to establish DBS as a method for performing pharmacokinetic studies in children.