I will try to explain this as I have PD and have studied about the drugs and treatments. Any of the drugs may cause side effects that are similar to the PD itself. So any of the meds may worsen symptoms or cause other serious side effects so it important to be working closely with a Dr. familiar with the disease. But to say that dopamine antagonists actually worsen Parkinsonian symptoms is confusing.

Dopamine agonist medications — such as bromocriptine (Parlodel), pergolide (Permax), pramipexole (Mirapex) and ropinirole (Requip) — may be used alone to delay the need for levodopa, or may be used with levodopa to increase its effectiveness or reduce the amount of levodopa needed. Dopamine agonists function by mimicking the effects of dopamine. Most patients who start with only a dopamine antagonist need to add levodopa within a few years. To minimize side effects, very low doses are used initially and the dose is increased gradually. Older patients can be especially sensitive to these drugs, which can cause symptoms of confusion, hallucinations and feeling weak because of low blood pressure.

Hope this information helps. Oh and to the other person answering a person with PD may drive a car because there are varying levels of symptoms.

Haven’t got a clue cos i’m only 13 but
An antagonist is one who antagonises, and auto is short for automatic, car or electric thing, and a receptor is a thing that receives something. So an autoreceptor antagonist would be an electric person who is very antagonising and drives around in a car while trying to receive enough reception to make a phone call. And its illegal for people with parkinsons to drive cars anyway so I doubt it would help.