Type 2 diabetes mellitus (T2DM) is a metabolic condition associated with increased morbidity, mortality and healthcare costs, with poor medication adherence to antidiabetic medications being a major barrier to optimal risk-factor control. Treatment complexity, due to polypharmacy and burdensome dosing regimens, is a key contributor to medication non-adherence in people with T2DM. Fixed-dose combination (FDC) therapy, in which two or more drugs are co-formulated into a single dosage, has emerged as a key strategy to reduce treatment burden, simplify dosing and potentially improve adherence in T2DM. This narrative review evaluates the evidence for FDC therapy as a means of improving medication adherence in people with T2DM. We summarise the development of FDCs, commonly used antidiabetic regimens, patient-reported benefits and their role in clinical practice. Evidence from randomised controlled trials (RCTs) assessing medication adherence is limited, but observational studies consistently demonstrate improved adherence among patients prescribed FDCs compared with free-equivalent combination regimens. Systematic reviews and meta-analyses support these findings, showing that FDCs attenuate the decline in medication adherence observed when transitioning from monotherapy to combination therapy. Additional benefits of FDC therapy include greater treatment satisfaction, potential cost-effectiveness and safety profiles comparable to their individual components. However, challenges associated with FDC therapy remain, including limited dosing flexibility, difficulties in titration and a paucity of long-term adherence data. Further research, particularly RCTs comparing FDCs with equivalent separate combinations and long-term follow-up data, are needed to confirm these benefits and inform clinical guidelines. Overall, FDC therapy is beneficial for simplifying diabetes treatment and improving medication adherence in T2DM.
Highton et al. (Fri,) studied this question.