Mirabegron

Detailed information

General information about assessment reports

Since 2006, an Environmental Risk Assessment (ERA) for the active pharmaceutical substance shall accompany an application for a marketing authorisation in EU for a medicinal product for human use. Parts of environmental data are available in the public assessment report (PAR/EPAR for centrally approved medicines). Environmental considerations are not included in the benefit-risk assessment for human medicines. If new data emerge after approval that necessitate an update of the environmental risk assessment, a variation application (“type IB C.I.z variation”) must be submitted to the regulatory authority.

The PEC (predicted environmental concentration) values used to calculate risk in the manufacturers' assessment reports are based on the estimated use of the medicinal product to which the assessment report relates, as well as possibly other products from the same company, not all medicinal products containing the same active substance.

Assessment report Betmiga 2024

Assessment report for Betmiga (mirabegron), type II variation for a new pharmaceutical form and indication, Astellas Pharma Europe, 27 June 2024, EMA/330048/2024.

Hazard

Persistence: Mirabegron is considered very persistent, based on low biodegradability (21% after 28 days in OECD 301) and long sediment half-lives (up to 235.8 days at 12 °C in OECD 308). The substance shows medium to very high sorption to soil, with over 10% shifting to sediment, triggering further testing. Its transformation products are also potentially persistent.

Bioaccumulation: log K_ow -0.4 (pH 4); 0.3 (pH 7); 2.0 (pH 10).

Toxicity: There are data for 3 trophic levels, most sensitive crustacean NOEC 1.01 microg/L. Comment: According to communication with the Swedish Medical Products Agency on 2025-11-12, mg/L should be used for all studies. See also the comment below. The NOEC is therefore 1 010 microg/L.

Risk

The risk, PEC/PNEC, calculated from data in the assessment report from a European perspective:

PEC = 0.25 microg/L.

PNEC = Lowest NOEC, 1 010 microg/L/10 (Assessment Factor (AF) for 3 chronic studies) = 101 microg/L

PEC/PNEC = 0.002475 which gives the risk insignificant.

Assessment report Betmiga 2012

Assessment report for Betmiga (mirabegron) 18 October 2012 EMA/706651/2012/corr.

Hazard

"During the Phase I of the assessment, the calculation of the predicted environmental concentration (PEC) has resulted in a PEC_surfacewater above 0.01 μg/L, and consequently a Phase II environmental fate and effect analysis was carried out. The assessment of “Aerobic Transformation in Aquatic Systems’ study (OECD 308) was not carried out according to OECD recommendations. Although the guideline requests to conduct both aerobic and anaerobic transformation the study only included data on aerobic transformation. The Applicant justified the lack of including an anaerobic assessment in the study as the ’Questions and Answers on 'Guideline on the Environmental Risk Assessment of Medicinal Products for Human Use' (EMA/CHMP/SWP/44609/2010), states that this type of study would not be required for this type of medicinal product. This was considered acceptable and no further clarification with respect to the ERA is warranted."

Persistence OECD 301: "Mean O₂ consumption Day 19: 10%, Day 28: 21%." Anmärkning: "not readily biodegradable".

OECD 308: "DT₅₀, water = 1.1–1.2, DT₅₀, sediment = 20–111, DT₅₀, whole system = 1.2–1.3, % shifting to sediment =10."

Bioaccumulation log P_ow: at pH 4 the value -0.4 is reported, at pH 7 the value 0.3 is reported and at pH 10 the value 2.0 is reported. Conclusion: not B.

Chronic toxicity: There are data for 3 trophic levels, lowest NOEC for crustacean (Daphnia sp.) 1 010 microg/L. Comment: Reported in this assessment report as 1.01 mg/L. Compared with data from the 2024 assessment report, where the value is given as 1.01 microg/L. One of the units is likely incorrect. According to communication with the Swedish Medical Products Agency on 2025-11-12, mg/L should be used for all studies.

Risk

The risk, PEC/PNEC, calculated from data in the assessment report from a European perspective:

PEC = 0.25 microg/L.

PNEC = Lowest NOEC, 1 010 microg/L/10 (Assessment Factor (AF) for 3 chronic studies) = 101 microg/L

PEC/PNEC = 0.00247 which gives the risk insignificant.

Fass environmental information

Fass environmental information for Betmiga from Astella Pharma AB (retrieved on 2025-11-11).

Hazard

Persistence: No data.

Bioaccumulation: The LogP value of mirabegron has been estimated at 1.29 using the ALOGPS 2.1 online software.

Toxicity: No data.

Risk

PEC/PNEC is based on sales data in Sweden in year 2023.PNEC data from assessment reports.

PEC = 0.089 microg/L.

PNEC = Lowest NOEC, 1 010 microg/L/10 (Assessment Factor (AF) for 3 chronic studies) = 101 microg/L.

PEC/PNEC = 0.000881 which gives the risk insignificant.

Environmental assessment by Goodpoint 2026

Both ecotoxicological effect data and environmental measurements are limited for incontinence pharmaceuticals. However, excretion data, available ecotoxicological effect data, and risk assessment using the fish plasma model for both parent compounds and active metabolites consistently indicate a negligible environmental risk associated with the use of the three anticholinergic substances solifenacin, tolterodine, and fesoterodine from a Swedish perspective. For mirabegron, which is considered persistent in the environment, the risk is somewhat higher but still low. Therefore, no substitutions are recommended from an environmental risk perspective.