Kommersiellt obunden läkemedelsinformation riktad till läkare och sjukvårdspersonal


Hazard 4 P 3 B 0 T 1 Risk See below


The T-value in the score for hazard refers to acute toxicity. Underlying data for P, B and T are from Fass.se, see below.

Concentrations of trimethoprim in Swedish wastewater treatment plants is likely to select for bacterial resistance.

Trimethoprim is included in the Stockholm County Council's table of pharmaceuticals with risk for negative environmental impact according to the environmental program, 2017–2021. Trimethoprim has been detected in treated wastewater, surface water and fish in Stockholm County in the last five years (2012–2016).

Studies have shown that even low concentrations of antibiotics in the environment may trigger antibiotic resistance and therefore measures should be taken to ensure that as little as possible ends up in our environment.

Is recommended in The Wise list. Environmental classification of pharmaceuticals is taken into consideration, sometimes with other environmental aspects, when selecting pharmaceuticals for the Wise list. When comparable pharmaceuticals are equivalent to medical effects, safety and pharmaceutical efficacy, environmental impact and price are considered.

Fass environmental information

Fass environmental information for Bactrim (sulfamethoxazole, trimethoprim) (downloaded 2013-07-03).


Persistence: "Based on several measurements, half-lives in the aquatic compartment are estimated at 20–100 (geometrical average ~45) days, >42 days and 5.7 days in a microcosm study, which qualifies Trimethoprim as nonpersistent to persistent."

Bioaccumulation: Log D of 0.76 at pH 7.

Acute toxicity: There are data for 3 trophic levels, lowest for algae (Rhodomonas salina, Cryptophyceae) 16 000 microg/L.


PEC/PNEC is based on sales data in Sweden in year 2009. PEC/PNEC = 0.008 which gives the risk insignificant, i.e. consideration has not been given to measured levels in the environment..

No recent environmental information on Fass.se has been found (2018-09-10). It is voluntary for manufacturers to provide information about environmental impact on fass.se.

Suggestions on how to reduce the release of trimethoprim

Concrete proposals on how to work to reduce emissions of environmentally harmful pharmaceuticals on the list have been developed in close cooperation with the Stockholm Drug and Therapeutics Committee's expert advice. The action proposals were developed from an environmental perspective. The patient's best always goes first and several pharmaceuticals on the list are also included in the Wise list. However, for such pharmaceuticals, there may be measures that could reduce the environmental impact.

Concrete proposal for trimethoprim

  • Trimethoprim is recommended in Wise list after urinary cultivation if the bacterium is sensitive.
  • In the empirical treatment of lower urinary tract infection without fever, the Wise list recommendation is nitrofurantoin, which is better than trimethoprim or pivmecillinam from an environmental point of view. Antibiotic rotation at the individual level is recommended to reduce the risk of resistance development.
  • For antibiotics, the general rule is as restrictive use as possible without risking the patient's health. Relevant cultivations are important in order to choose antibiotics that have a good effect with as narrow spectrum as possible.

Report Goodpoint 2018

Comparative assessment of environmental risk and risk of resistance selection in the environment using trimethoprim and pivmecillinam in Sweden.

From a resistance-selection-risk perspective in wastewater treatment plants, pivmecillinam appears to be a slightly better alternative than trimethoprim.


  1. Fass.se för vårdpersonal
  2. Goodpoint. Prioritering av läkemedel med miljörisk inom SLL. Stockholm: Goodpoint; 2016. Rapport LS 2016–0634.
  3. Binelli A, Parolini M, Cogni D, Pedriali A, Provini A. A multi-biomarker assessment of the impact of the antibacterial trimethoprim on the non-target organism Zebra mussel (Dreissena polymorpha). Comp Biochem Physiol C Toxicol Pharmacol. 2009;150:329-36.
  4. IVL Swedish Environmental Research Institute Ltd. Fick J, Lindberg RH, Kaj L, Brorström-Lundén E. Results from the Swedish National Screening Programme 2010. Subreport 3. Pharmaceuticals.
  5. IVL Swedish Environmental Research Institute Ltd Fick J, Lindberg RH, Fång J, Magnér J, Kaj L, Brorström-Lundén E. Screening 2014. Analysis of pharmaceuticals and hormones in samples from WWTPs and receiving waters. Rapport C 135.
  6. Bengtsson-Palme J, Larsson DG. Concentrations of antibiotics predicted to select for resistant bacteria: Proposed limits for environmental regulation. Environ Int. 2016;86:140-9.
  7. Gullberg E, Cao S, Berg OG, Ilbäck C, Sandegren L, Hughes D et al. Selection of resistant bacteria at very low antibiotic concentrations. PLoS Pathog. 2011;7:e1002158.
  8. SLL. Sammanställning av läkemedelsprovtagningar - Bearbetning av regional försäljningsstatistik av läkemedel samt datamaterial från Stockholms läns landstings mätprogram för läkemedelssubstanser i vattenmiljö, 2012–2016.
  9. Stockholms läns landsting. Förteckning över miljöbelastande läkemedel med åtgärdsförslag framtagen inom ramen för SLL:s miljöprogram 2017–2021.
  10. Goodpoint. Jämförande bedömning av miljörisk och risk för resistensselektion i miljön vid användning av trimetoprim och pivmecillinam. Stockholm: Goodpoint; 2018.
  11. Stockholms läns landsting. Kloka listan (Wise list).
  12. Stockholm County Council. The Wise List 2015.

Author: Health and Medical Care Administration, Region Stockholm