Drug interactions: Rifampin may decrease ondansetron levels.
The Onset/Peak/Duration for ondansetron is 20 sec-4 min (IV<IO<translingual<IM)/10-40 min/4 hr.
When administering, if the ODT comes in a blister pack, peel back the foil to remove the pill to avoid damage to the medication. Then, place it on the casualty’s tongue and allow the medication to dissolve completely. Do NOT administer with water, rather allow the medication to dissolve using the casualty’s own saliva. Once dissolved, the remaining solution will ultimately be swallowed with the casualty’s saliva, but delaying that to allow for increased absorption through the oral mucosa is ideal. If IV or IO access is established and the parental form is available, consider administering the medication by one of those routes.
Once ondansetron was no longer under patent and became affordable, evaluations for its use in tactical situations were carried out and the results demonstrated equivalent efficacy to promethazine. Also, the safety profile on ondansetron is better than the other antiemetics reviewed for use in the tactical environment. In particular, it does not cause sedation or hypotension and doesn’t have the central and autonomic nervous system side effects seen in other anti-nausea medications. Of note, the use of ondansetron to treat nausea and vomiting associated with combat wounds or analgesic opioids is an off-label use.