It is a member of the class of nitrocatechols.
The most frequent undesirable effects caused by entacapone relate to the increased effects of L-DOPA, such as involuntary movements (dyskinesias).These occur most frequently at the beginning of entacapone treatment. Others common side effects are gastrointestinal problems, including diarrhoea, nausea and abdominal pains. The substance may cause urine to turn reddish-brown. This is a harmless side effect and is not a cause for concern. In studies with entacapone, some people have reported experiencing a dry mouth.
The Association between Adherence to Levodopa/ Carbidopa/ Entacapone Therapy and Healthcare Utilization and Costs among Patients with Parkinson's Disease
Jan 01, 2011; Introduction Introduced 4 decades ago, levodopa remains the most effective therapy for patients with Parkinson's disease....