Objectives Diabetes is a major public health concern worldwide, particularly in low-income and middle-income countries (LMICs). Limited data exist on the status of access to diabetes medicines in LMICs. We assessed the utilisation and affordability of diabetes medicines in Iran as a middle-income country.

Design We used a retrospective time-series design (2000–2012) and assessed national diabetes medicines’ utilisation using pharmaceuticals wholesale data.

Methods We calculated defined daily dose consumptions per population days (DDDs/1000 inhabitants/day; DIDs) indicator. Findings were benchmarked with data from Organization for Economic Co-operation and Development (OECD) countries. We also employed Drug Utilization-90% (DU-90) method to compare DU-90s with the Essential Medicines List published by the WHO. We measured affordability using number of minimum daily wage required to purchase a treatment course for 1 month.

Results Diabetes medicines’ consumption increased from 4.47 to 33.54 DIDs. The benchmarking showed that medicines’ utilisation in Iran in 2011 was only 54% of the median DIDs of 22 OECD countries. Oral hypoglycaemic agents consisted over 80% of use throughout the study period. Regular and isophane insulin (NPH), glibenclamide, metformin and gliclazide were the DU-90 drugs in 2012. Metformin, glibenclamide and regular/NPH insulin combination therapy were affordable throughout the study period (∼0.4, ∼0.1, ∼0.3 of minimum daily wage, respectively). While the affordability of novel insulin preparations improved over time, they were still unaffordable in 2012.

Conclusions The utilisation of diabetes medicines was relatively low, perhaps due to underdiagnosis and inadequate management of patients with diabetes. This had occurred despite affordability of essential diabetes medicines in Iran. Appropriate policies are required to address the underutilisation of diabetes medicines in Iran.