Q5. Ondansetron has a number of contraindications. Describe the mechanisms that explain why ondansetron should not be taken with apomorphine and rifampicin. (5 marks)
Taking ondansetron and apomorphine is not recommended, as taking these drugs at the same time can cause symptoms such as profound hypertension, bradycardia, chest pain, and loss of consciousness. The risk of taking these drugs outweighs the benefits.
Taking ondansetron and rifampicin is not recommended as taking Rifampin decreases the level of effect of ondansetron by affecting hepatic/intestinal enzymes CYP3A4 metabolism. (RxList, 2018) decreasing the potency of ondansetron with rifampin will result in having to increase the dose of ondansetron to receive the therapeutic effect.