The primary side effect of tigilanol tiglate (TT) on equine sarcoids is a localized inflammatory response at the treatment site, causing bruising, swelling, pain, and tissue sloughing (necrosis and loss of the tumor mass). Horses may also experience minor lethargy and discomfort for a few days after treatment. More serious, but less common, complications can include jugular thrombophlebitis, or inflammation of a vein, and lymph node abscessation. [1, 2, 3, 4]  

Common Side Effects 
  • Localized Inflammation: A rapid, intense inflammatory response occurs at the treatment site. [1, 5]  
  • Tissue Necrosis and Sloughing: The tumor undergoes hemorrhagic necrosis (bleeding death of tissue) and then sloughs off the wound. [1, 5]  
  • Pain and Discomfort: Horses may experience discomfort at the injection site for several days. [1, 3]  
  • Lethargy: Some horses may show signs of lethargy or inappetence for the first 24-36 hours after treatment. [1, 3, 4]  
  • Bruising and Discoloration: Bruising and discoloration at the treatment site are common. [1, 2]  
  • Ulceration: Bleeding ulcerations at the site of injection are possible. [2]  
Management and Other Considerations 
  • Concurrent Medications: The inflammatory response, pain, and edema (swelling) are often managed with concomitant medications, such as non-steroidal anti-inflammatory drugs (NSAIDs) or dexamethasone. [3, 4]  
  • Wound Healing: The wound that forms after the tumor sloughs typically heals uneventfully. [1, 3]  
  • Overly Robust Response: While the inflammatory response is crucial for the drug's action, an overly robust response can lead to more extensive swelling and larger wounds. [6]  
  • Dose Management: It is crucial not to administer excessive doses of TT to avoid complications. [4, 7]  
  • Adjunctive Therapy: In some cases, a single treatment may not be sufficient, and multiple treatments may be required. [4]  
AI responses may include mistakes.
[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC7509040/
[2] https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=05b71840-ac18-4f83-8701-bd63d8782aaf
[3] https://www.researchgate.net/publication/344265786_Use_of_the_Intratumoural_Anticancer_Drug_Tigilanol_Tiglate_in_Two_Horses
[4] https://equimanagement.com/research-medical/novel-equine-sarcoid-treatment/
[5] https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2020.00639/full
[6] https://qbiotics.com/pub/DeRidder_Use_of_TT_in_two_horses_2020.pdf
[7] https://www.researchgate.net/figure/Occurrence-and-category-of-adverse-events-occurring-at-frequency-of-5-in-117-dogs_fig6_342214077