My Friend, Whom I Am Caring For Is On Levothyroxine.

My friend, whom I am caring for is on Levothyroxine. He has dimensia. He has big issues with restlessnes, irritability, and general anxiety. He calls out (yells is more accurate) and we cannot find enough ways to distract, occupy his time, etc. Sometimes we can find something that works and 10 minutes later we are back to the yelling again.
Could Levothyroxine be contributing to this? He is 99 years old. Loves to roll out in his wheelchair to pick tomatoes etc...but yet is so upset/ restless.