Cost Variation Analysis of Metformin-Based Dual Fixed-Dose Combinations Prescribed in India

Abstract

Background: Metformin is the initial pharmacological intervention for managing type 2 diabetes mellitus (T2DM). However, its effectiveness for achieving optimal glycemic control diminishes over time, requiring the addition of other oral antidiabetic drugs (OADs) to the treatment regimen. The widespread adoption of metformin-based fixed-dose combinations (FDCs) in India necessitates an investigation into their impact on affordability and access. This study, therefore, undertook a cost variation analysis of available dual FDCs containing 500 mg of metformin to illuminate these implications.

Methods: The cost data were sourced from retail websites. We analyzed cost variation by calculating the cost variation percentage (CV%) and the average cost of all FDCs. The relationship among cost variation, average cost, and the number of manufacturing companies was statistically assessed using Pearson's correlation in Microsoft Excel.

Results: Among the 15 FDCs analyzed, the metformin + dapagliflozin combination exhibited the most substantial cost variation, reaching 436.2%. Conversely, the metformin + saxagliptin combination recorded the highest average cost per tablet, at 45.16 rupees (equivalent to 0.52$). A statistically significant negative Pearson's correlation was observed between the average cost of drugs and the number of manufacturing companies across all FDCs (r = −0.595, p = 0.019*) and in the metformin + dipeptidyl peptidase-4 inhibitors (DPP4is) group (r = −0.900, p = 0.037*).

Conclusion: In our study, the co-administration of metformin with the newer therapeutic agents (dapagliflozin and saxagliptin) demonstrated the highest variability in pharmaceutical pricing. This finding underscores the necessity for regulatory intervention regarding the costs of these FDCs within the Indian market.