Which of the following drugs is known to increase EPS effects with prolonged use?

Prolonged use of metoclopramide is associated with an increased risk of extrapyramidal symptoms (EPS), which include symptoms such as tremors, rigidity, bradykinesia, and other movement disorders. Metoclopramide is a dopamine antagonist that is primarily used as an antiemetic and gastric stimulant. Over time, especially in elderly patients or those on prolonged therapy, the blockade of dopamine receptors can lead to the development of these adverse effects.

The risk of EPS with metoclopramide is particularly notable because the drug can be used for extended periods, which increases the likelihood of these side effects, especially in susceptible individuals. This potential for EPS makes careful monitoring necessary when prescribing metoclopramide for chronic use.

Ondansetron, prochlorperazine, and promethazine have varying profiles regarding their potential to cause EPS. While prochlorperazine is also a dopamine antagonist and can cause EPS, the focus here is on metoclopramide due to its specific association with prolonged therapy leading to increased EPS risks. Ondansetron primarily works as a serotonin 5-HT3 receptor antagonist and is much less likely to induce EPS. Promethazine, while it can cause some movement disorders, is