Of note, Mehagnoul-Schipper et al. [2] demonstrated that administration of 125 mg of levodopa/benserazide (DOPA decarboxylase inhibitor) twice a day did not contribute to the severity of BP decline in orthostatic and postprandial hypotension; however, other studies have reported that levodopa and carbidopa have vasodilatory and negative inotropic effects, specifically worsening OH in PD with autonomic failure [42, 43]. This evidence concerns the gene DDC and Parkinson disease.