how long does it take for ondansetron to work

Ondansetron typically starts to work within 30 minutes after taking an oral dose, but it can take up to 1 to 2 hours for the full effect to be felt. The onset time may vary depending on the formulation (oral tablet, orally disintegrating tablet, or injection) and individual factors such as metabolism, age, and other medications taken. For example, orally disintegrating tablets may act faster due to quicker absorption. This medication is usually taken before events likely to cause nausea, such as chemotherapy, surgery, or radiation treatments, to prevent nausea and vomiting effectively.