Safety and efficacy of Monimax® (monensin sodium and nicarbazin) for turkeys for fattening

coccidiostat, Monimax, monensin sodium, nicarbazin, safety, efficacy, turkeys for fattening
First published in the EFSA Journal
22 December 2017
29 November 2017
Last Updated
6 August 2018. This version replaces the previous one/s.
Scientific Opinion


The coccidiostat Monimax® (monensin sodium and nicarbazin) is considered safe for turkeys for fattening at the highest use level of 50 mg monensin and 50 mg nicarbazin/kg complete feed. The simultaneous use of Monimax® and certain antibiotic drugs (i.e. tiamulin) is contraindicated. For both active substances, the metabolic pathways in the chicken are similar to those in the turkey and rat. Nicarbazin, when ingested, is rapidly split in its two components dinitrocarbanilide (DNC) and 2-hydroxy-4,6-dimethylpyrimidine (HDP) which behave independently. Monimax® does not represent a genotoxic risk. No safety concerns would arise from the nicarbazin impurities p-nitroaniline and methyl(4-nitrophenyl) carbamate. The lowest no observed effect level (NOEL) identified for monensin sodium in a developmental study in rabbits was 0.3 mg monensin sodium/kg body weight (bw) per day for maternal toxicity in rabbits. The lowest no observed adverse effect level (NOAEL) identified in a 52‐week study in rat using DNC + HDP was 20 mg DNC + 8 mg HDP/kg bw per day. No significant interaction between monensin sodium and nicarbazin is expected from toxicological studies. The use of Monimax® at the highest proposed dose will not pose a risk to persons consuming animal products from treated turkeys for fattening. No withdrawal time is required for Monimax® in turkeys for fattening. Residue data comply with the established maximum residue limits for monensin and DNC. Monensin sodium presents a hazard by inhalation and may also be associated with dermal toxicity. Monimax® is not a skin irritant; however, no data are available for the eye irritation potential of monensin. Monimax® is not a skin sensitiser. Based on the available data, the FEEDAP Panel cannot conclude on the safety of Monimax® for the environment. Monimax® has the potential to control coccidiosis in turkeys for fattening at a minimum concentration of 40 mg monensin and 40 mg nicarbazin/kg complete feed.

Panel members at the time of adoption

Guido Rychen, Gabriele Aquilina, Giovanna Azimonti, Vasileios Bampidis, Maria de Lourdes Bastos, Georges Bories, Andrew Chesson, Pier Sandro Cocconcelli, Gerhard Flachowsky, Boris Kolar, Maryline Kouba, Marta López-Alonso, Secundino López Puente, Alberto Mantovani, Baltasar Mayo, Fernando Ramos, Maria Saarela, Roberto Edoardo Villa, Robert John Wallace, Pieter Wester, Paul Brantom, Ingrid Halle, Patrick van Beelen, Orsolya Holczknecht, Maria Vittoria Vettori andJürgen Gropp
Panel on Additives and Products or Substances used in Animal Feed
feedap [at]
EFSA Journal 2017;15(12):5094
Question Number
On request from
European Commission
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