Project funded in 2013 and completed in 2014

As of July 1, 2016 the Canadian Code of Practice for the Care and Handling of Pigs states that piglets must be provided with appropriate pain control during castration and tail docking. The timing of these procedures often coincides with iron supplementation for piglets, leading many producers to mix the iron with the analgesic (pain killer), in order to save time and minimize the number of injections given.  However little knowledge exists regarding the impact of mixing meloxicam (Metacam) or flunixin meglumine (Banamine), two common analgesics, with iron dextran.  Drug interactions can occur when multiple drugs are mixed together in the same delivery system i.e. bottle, or syringe, with the result being a reduced availability of one drug due to the presence of the second.
University of Guelph researcher Dr. Ron Johnson tested for a response when each of the pain medications were mixed together in a bottle with iron dextran.  What they found was that the recoverable amounts of both analgesics were reduced after only two hours.   A full 24 hours after mixing there was a 30% reduction in the amount of Banamine present, and a 10% reduction in Metacam.  When the mixture of iron with either analgesic was injected into a pig and repeated blood samples were taken, there was no difference in the effect on piglet blood hemoglobin compared to an injection of just iron. However, pigs injected with the iron/analgesic mixtures has a lower than expected amount of analgesic level in their bloodstream. These results suggest that iron dextran interacts with both Metacam and Banamine, decreasing their availability in the piglets’ circulation. This may mean that if iron is mixed with the analgesic, piglets are not receiving the full dose of pain reliever.   If veterinarians recommend the practice of mixing an analgesic with iron dextran, it is suggested that the mixed product be used immediately due to the reduction of available pain-reliever over time.
Dr. Johnson and Dr. Terri O’Sullivan are completing further research in this area under Ontario Pork funded project 16-011 (final report due in the fall of 2018).
 

Further Reading:
www.uoguelph.ca/osrn/sites/uoguelph.ca.osrn/files/public/MWD%202015.pdf  (page 13)
www.ontariopork.on.ca/Research/Active-Recently-Completed/assessing-the-efficacy-of-ketoprofen-and-meloxicam-when-mixed-with-iron-dextran-on-pain-relief-following-castration-in-piglets

 

Ronald Johnson bio