Dr. Elizabeth Maxwell
Oral analgesic options available on the market for companion animals have questionable bioavailability and variable efficacy.
“The limitations and side effects associated with current canine oral analgesic medications demonstrate the need to investigate novel pharmacologic options for the management of canine pain, with fewer adverse effects,” said Elizabeth Maxwell, D.V.M., a clinical assistant professor of small animal surgical oncology and a certified veterinary pain practitioner.
In collaboration with researchers from UF’s College of Pharmacy, Maxwell is leading a clinical trial now underway at UF’s Small Animal Hospital to investigate a tropical plant indigenous to Southeast Asia, known as Mitragyna speciosa, or kratom, which is of interest to scientists due to its opioid-like effects.
“Kratom is commonly utilized by people as a self-treatment of various conditions, including the relief of chronic pain, mood enhancement, and/or opioid withdrawal symptoms,” Maxwell said. “Over 40 alkaloids that have been isolated from the leaves of the kratom plant, the most abundant of which is mitragynine.”
Several studies suggest that various preparations of mitragynine cause analgesic, antipyretic, antidiarrheal, euphoric, anti-depressant, and anxiolytic effects, leading to its perceived therapeutic activity. Mitragynine exerts its action by binding to opioid, alpha adrenergic, dopamine, and serotonin receptors.
In order to evaluate the potential utility of kratom in the management of canine pain, pharmacokinetic studies were needed to determine dosing and adverse effects, Maxwell said.
“Therefore, we conducted two studies investigating the safety and pharmacokinetic properties of mitragynine and its metabolite 7-hydroxymitragynine,” she said. Administration of these compounds were well tolerated, with no observed adverse events.
“We are now evaluating the effectiveness of kratom in the management of canine osteoarthritis,” Maxwell said. “In the future, we plan to evaluate kratoms efficacy in management of surgical pain.”
