"How to use CBD as a Parkinson patient to avoid any drug interaction, like if I take medicine in the morning and CBD in the evening or vice versa, Is this gap enough? I am currently using (Requip + Amantadine sulfate + Co Valtec 160/12.5)"
I’m not sure exactly what "interactions" you are referring to. Cannabinoids are metabolized using enzymes in the CYP450 pathway, and this is true of many medications, including the ones you are taking. This does raise the possibility that competition for available enzyme could reduce the rate of breakdown of the medication and cause an increase in the amount circulating. The extent of this type of interaction in the actual clinical setting is far from clear, and I usually advise patients to begin with smaller amounts of cannabis until they determine how it is affecting their other medications. I doubt the alternating dose interval you suggest would be metabolically significant, but there are situations where additive effects cause adverse symptoms such as dizziness or sedation; this is commonly encountered when combining cannabis with opioids or alcohol. There have been reports of amantadine and cannabis together causing drowsiness so I do suggest separating those by a few hours.