Finally, on February 20, 1792, President Washington formally created the U.S. Postal Service with the signing of the Postal Service Act, which outlined in detail Congressional power to establish official mail routes.
The two concerns are firstly that Haldol (like all other antipsychotics) can cause tardive dyskinesia and as that is clinically related to Parkinson's this is an express concern with people with Parkinson's.
There are other medications that are usually more effective for Parkinson's disease and related disorders than these. The drugs should not be used for other conditions, like treating side effects of other medications (for example the movement side effects of antipsychotic medications).