Parent signed POA while on heavy duty drugs. What is the best legal approach to nullify POA?

You are talking about Undue Influence and Embezzling. Call the police

Can you verify what you mean by "agent"? I haven't heard this term used before regarding a Power of Attorney.

I think you need some legal help. Are you willing to report the POA as abusing an alder? Do you have evidence of these "gifts"?

no. notary only who is friends with the agent.

Was the current Power of Attorney signed in front of an Attorney who prepared the document? Sounds like it wasn't as an Attorney wouldn't have let a client, who is on heavy meds, sign any type of paperwork.

By the way, nothing is *gifted* under a Power of Attorney, only under a Will or a Trust.

thats not possible because of parents condition.

If you parent is of clear mind, he/she can make a new Power of Attorney, thus void the previous one. Have an attorney write up the POA and have your parent sign in front of the attorney and the required number of witnesses.