Hello Thank you for trusting HCM Dear here is the some of the reasons for poor response to Parkinson s disease. 1.diagnosis of Parkinson s disease is wrong (presence of Parkinson-plus syndrome , etc) 2. drug interaction affecting levodopa like increased clearance, poor absorption, blocking at receptor sites (3) insufficient dose of levodopa (4) poor drug absorption from the GI tract due to concurrent disease (5) increased metabolism due to concurrent disease, resulting in a shortened therapeutic period (6) progression of Parkinson s disease with loss of dopaminergic neurons (7) adverse effects of levodopa, including overdosage (8) development of problems unrelated to dopaminergic status like cognitive impairment or dementia, depression, dysautonomia. Please consult your doctor he revise the dose and drugs and treat you accordingly.