Tissue damage and concentration at the injection site after intramuscular injection of chemotherapeutics and vehicles in pigs.

Intramuscular injection sites were examined for macroscopical and microscopical changes and for residues of drugs six and 30 days after injection of chemotherapeutic preparations or vehicles in swine. The chemotherapeutic preparations contained sulphonamide and/or trimethoprim. All the chemotherapeutic preparations and the vehicles except physiological saline and sterile water caused macroscopical and microscopical changes, mainly appearing as areas of necrotic muscle tissue six days after the injection and as scar tissue 30 days after the injection. Residues of drugs were found at nearly all the injection sites six days after the injection, while 30 days after the injection only residues of sulphonamides were detectable in nearly half of the injection sites.