Effect of Levodopa on Cardiovascular Autonomic Function in Parkinson's Disease

• Status: Recruiting
• Trial end date: 2024-08-01
• Target enrollment: 0
• Participant gender: All

Summary

Levodopa is a precursor of dopamine and is the treatment of choice to treat the motor symptoms of Parkinson's disease (PD); however, the effect of levodopa on cardiovascular autonomic function in PD is poorly understood. Orthostatic hypotension has been documented as a potential side effect of levodopa. As a result, clinicians may be reluctant to prescribe levodopa in patients with PD with neurogenic orthostatic hypotension (PD+OH), which leads to suboptimal management of motor symptoms. On the other hand, other studies failed to show any clear relationship between levodopa and orthostatic hypotension in patients with PD. Important limitations of prior studies include the lack of detailed investigation of baroreflex cardiovagal and sympathetic noradrenergic functions and the fact that the same patients were not tested on and off levodopa.

The investigators propose to investigate the effects of levodopa on cardiovascular autonomic function in patients with PD+OH and PD without neurogenic orthostatic hypotension (PD-OH) by performing standardized autonomic testing in the same patients on and off levodopa.

• Phase: N/A
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: University of Utah
• Treatments: Levodopa

Criteria

Inclusion Criteria:

• Subjects with a diagnosis of Parkinson's disease

• For the subgroup of participants with orthostatic hypotension (OH), OH will be defined by a sustained drop in systolic blood pressure > 20 mmHg and/or a drop in diastolic blood pressure > 10 mmHg within 3 minutes from supine to standing during tilt not attributable to medications. Autonomic testing and a ratio of orthostatic heart rate change/systolic blood pressure change < 0.5 bpm/mmHg will confirm the neurogenic etiology.

Exclusion Criteria:

• Any medication indicated for withdrawal that would result in undue risk to the participant if discontinued or that would confound heart rate and blood pressure measures

• Cognitive impairment that limits the ability to follow instructions