In this task, you will be given sentences in which your task is to recognize the name of the drug or medicine. Drugs are substances that change a person's mental or physical state. They can affect how your brain works, how you feel and behave, your understanding, and your senses. Although there might be several correct answers, you need to write one of them.

Q: Phenytoin toxicity: an easily missed cause of cerebellar syndrome.

A: Phenytoin
****
Q: These results indicate that lithium may cause biochemical hyperparathyroidism.

A: lithium
****
Q: Anti-tuberculous drugs had been stopped on the 2nd day of therapy due to development of optic neuritis secondary to ethambutol administration at another hospital.

A:
ethambutol
****