Which medication is known to cause a prolonged QT interval?

Ondansetron is known to potentially cause a prolonged QT interval. This medication, which is primarily used as an antiemetic to prevent nausea and vomiting, is particularly important in patients who may have underlying heart conditions or are taking other medications that also prolong the QT interval. The mechanism behind this side effect relates to ondansetron's action on serotonin receptors, which can influence cardiac repolarization.

In contrast, ibuprofen, paracetamol (acetaminophen), and amoxicillin do not have a significant association with QT prolongation. Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that is primarily used to relieve pain and inflammation. Paracetamol is an analgesic and antipyretic that is typically safe regarding cardiac effects. Amoxicillin is an antibiotic that does not have documented QT interval effects. Hence, when considering the potential risks of ondansetron, it becomes clear why it is the medication recognized for this specific side effect.