The Defined Daily Dose (DDD), defined by the World Health Organisation (WHO) as the average dose prescribed according to a representative sample of prescriptions, has been used to standardise the dosing across all COMTi. The DDD for entacapone is 1g (5 x 200mg) and the corresponding DDD for opicapone is 50mg (1 x 50mg). Therefore, one dose of opicapone is assumed equivalent to 5 doses of entacapone.^8,9

Ongentys offers a significantly lower environmental impact compared to Entacapone. Taken as a single 50 mg capsule once daily,1 Ongentys provides a comparatively simpler dosing regimen. This translates into a predictable carbon footprint of just 48.68 gCO₂e.⁴

In contrast, Entacapone must be administered multiple times daily alongside levodopa, with the WHO-defined daily dose (DDD) requiring five 200 mg tablets (1 g total).^2,8 This results in 503.25 gCO₂e per day—more than 10 times the emissions of Ongentys. At the maximum recommended dose of 2 g (10 tablets daily), Entacapone’s emissions soar to 1006.5 gCO₂e, nearly 21 times higher than Ongentys.⁴

In the context of environmental impact, this stark difference highlights Ongentys as a more sustainable choice, supporting the NHS’s net zero ambitions and reducing the environmental burden from the use of medicines.⁶

The environmental impact of Entacapone is dramatically higher than that of Ongentys. On an annual basis, treatment with Ongentys results in 17,769.95 gCO₂e per patient—the equivalent of driving 66 car miles. In stark contrast, Entacapone at the equivalent DDD of 1 g produces 183,685.16 gCO₂e annually—over 10 times more, equating to 684 car miles. At the maximum dose of 2 g, the carbon footprint increased to 367,370.31 gCO₂e, or 1,368 car miles—more than 20 times the emissions of Ongentys.⁴

Ongentys in place of entacapone could represent a significant step toward reducing the carbon footprint in the management of people with Parkinson’s disease.

MCF classifier is a tool developed by YewMaker to provide carbon footprint insights for medicines. It is based on a peer-reviewed methodology. Central to this is the development of metrics to measure the efficiency and environmental impact of chemical reactions used in the manufacture of the active pharmaceutical ingredient (API).³ Process mass intensity (PMI) is the industry standard^10,11 and is derived by measuring the total mass of materials required to make 1kg of API, including reagents, reactants, solvents and catalysts, and is dependent on the molecular weight, molecular structure and complexity of the synthetic process.

Medicines contribute around 25% of NHS England’s emissions, with a few high-impact drugs (such as anaesthetic gases, nitrous oxide, and inhalers) driving a significant share. To tackle this, the NHS is partnering with patients, clinicians, and industry to cut emissions by reducing waste, improving access to the right medicines, and supporting informed, shared decision-making.⁷

In the journey to net zero, the carbon footprint of each medicine becomes increasingly important in prescribing and formulary decisions—not only to ensure clinical effectiveness and patient outcomes, but also to support environmental and financial sustainability.

MCF classifier has a rating tool that groups medicines based on the grams of carbon dioxide equivalent in grams (gCO2e). An overview of the grouping is pictured above: