Parkinson related issue. & contuine.

My father's left hand is shaking & numbness in left side for 3-4 mnths Consulted a physician & got to know its a Parkinson diseases was on this medication Pan 40, Atrova 40mg, Ecosprin, & Strocit Plus, Tab Etrobax for pain No improvement in 45 days so added Tab Pasitane 4mg, we couldnt find 4 mg so giving 2 tablets for 2mg each, Doctor advised once at nigth, due to miscommunication in family we gave twice a day 4mg, that is overdose for 3 days. From that time We have noticed his hand stops shaking 80% but He is forgetting things, talking to himself & looks confused, not talking much, slight change in tone while speaking, difference in walk from 2 days. please advise what to do. should be stop medicine for few days and restart at nigth or go with lower dose for 2mg at nigth & contuine. he is non debetic & bp goes up & down use cetanil 10mg. all blood reports ,USG, ECG and 2D came normal. Please advise. Thank You.