Trastuzumab is incompatible with dextrose solutions because mixing trastuzumab with dextrose (such as 5% dextrose) leads to rapid aggregation of the protein, especially in the presence of human plasma or serum. This aggregation results in the formation of insoluble protein complexes, which can compromise both the safety and efficacy of the drug by potentially causing infusion reactions or reducing therapeutic activity. The aggregation is particularly notable for monoclonal antibodies like trastuzumab that are formulated at an acidic pH (≤ 6.5), as these are more prone to forming aggregates when exposed to dextrose-containing solutions.

Because of this risk, manufacturers and clinical guidelines specifically instruct that trastuzumab should only be reconstituted and diluted in 0.9% sodium chloride (normal saline) and never in dextrose solutions.

Citations:

  1. https://pubmed.ncbi.nlm.nih.gov/31774346/
  2. https://pubmed.ncbi.nlm.nih.gov/20061815/
  3. https://www.oncologynewscentral.com/drugs/monograph/16623-399019/trastuzumab-intravenous
  4. https://www.herceptin.com/hcp/metastatic-gastric-cancer/dosing-and-administration/preparation-and-storage.html
  5. http://media.oncologynurseadvisor.com/documents/14/ona_stat0510_3272.pdf
  6. https://www.drugs.com/monograph/trastuzumab.html
  7. https://www.enhertuhcp.com/en/dosing/preparation-and-administration
  8. http://www.bccancer.bc.ca/drug-database-site/Drug%20Index/Trastuzumab_monograph.pdf