Participants with parkinson's disease will be administered Equfina 50 milligram (mg) tablets, orally, once daily in combination with levodopa-containing products. On the basis of symptoms, Equfina 100 mg tablet, orally, once daily may be selected for participants. All the participants will be observed for up to 24 weeks prospectively.

Equfina oral tablets.

The numbers of participants based on the types of ADRs and AEs will be calculated. Number of participants with serious ADRs and serious AEs will be calculated. The numbers of participants based on the types of serious ADRs and serious AEs will be calculated.

Factors affecting safety will be investigated. Investigation for any association with various factors are to be performed employing appropriate analytical methods (example, logistic regression analysis). The factors include: gender, age, inpatient/outpatient status, duration of the disease, severity of Parkinson's disease (Hoehn and Yahr scale), presence/absence and details of psychiatric symptoms, severity of hepatic impairment, comorbidities, presence/absence of surgical treatment for Parkinson's disease, presence/absence of comorbid retinal pathology, history of drug allergy, presence/absence of pregnancy/breast-feeding (for females only), and history of smoking.

Parkinson's disease motor examination will be performed using Unified Parkinson's Disease Rating Scale (UPDRS) part III, motor signs of parkinson's disease during "ON" time will be evaluated. It contains following items: (1) speech, (2) facial expression, (3) tremor at rest, (4) action or postural tremor of hands, (5) rigidity, (6) finger taps, (7) hand movements, (8) pronation-supinational movements of hands, (9) leg agility, (9) arising from chair, (10) posture, (11) gait, (12) postural stability, (13) body bradykinesia and hypokinesia. Each item is rated on a 5-point likert scale of 0 to 4: 0=normal, 1=slight, 2=mild, 3=moderate, and 4=severe. Higher the score the greater will be the severity.