Objective: Evaluate blood pressure response to levodopa/carbidopa in patients with synucleinopathies undergone to autonomic testing.

Background: Carbidopa/levodopa is the mainstay treatment of patients with synucleinopathies, such as Parkinson’s disease (PD), Lewy Bodies Dementia (LBD), and Multiple System Atrophy (MSA). Orthostatic hypotension is described as a common adverse effect related to levodopa. To evaluate this hypothesis, we performed an autonomic evaluation in patients with parkinsonism and orthostatic hypotension (OH) during the OFF and ON levodopa periods.

Method: Between January 01, 2024, and January 01, 2025, we examined patients referred to our center with previous diagnoses (PD, MSA, LBD) and new patients with parkinsonism and orthostatic hypotension. Both groups were under treatment with carbidopa/levodopa. Autonomic assessments were undertaken in the OFF-levodopa period. Patients discontinued carbidopa/levodopa 12 hours before the evaluation. Blood pressure (BP) and heart rate (HR) were taken in supine and upright positions in the ON-levodopa period.

Results: Our study included n=10 patients. The final diagnosis was PD (n=5), LBD (n=4), and MSA subtype P (n=1). Six males and four females with a mean age of 70±11 years. Seven patients (70%) had neurogenic OH, and two had non-neurogenic OH (20%). The average delta heart rate/systolic blood pressure ratio (ΔSBP/HR) at 3 minutes was 0.09 in patients with neurogenic OH. In the Valsalva maneuver, phase late II and IV were absent in 7 patients (70%). Seven had supine hypertension (70%). There were no significant changes observed in supine and orthostatic blood pressure in the Levodopa-ON period as follows: supine systolic BP (168±30 vs. 164±32, p=0.75=), supine diastolic BP (87±18 vs 87±18, p=0.99), supine HR (69±12 vs 67±9, p=0.74). Upright (tilted and standing up) BP at 3 minutes: systolic BP (127±23 vs. 123±22, p=0.78), diastolic BP (66±15 vs. 70±18, p=0.53), HR (79±14 vs 74±9, p=0.38) and ΔSBP/HR (0.24±0.32 vs 0.43±0.59, p=0.36).

Conclusion: Blood pressure did not significantly change between levodopa ON and OFF periods. Therefore, carbidopa’s inhibition would decrease catecholamine peripheral levels and produce generalized hypotension. We suggested seeking environmental factors that defeat the residual sympathetic response and increase the carbidopa effect when the subject stands up.

Figure 1

Table 1

Table 2

References: 1. Cani I, Guaraldi P, Giannini G, Sambati L, Barletta G, Cortelli P, Calandra-Buonaura G. Levodopa-induced orthostatic hypotension in parkinsonism: A red flag of autonomic failure. Eur J Neurol. 2024 Jan;31(1):e16061. Doi: 10.1111/ene.16061.
2. Earl T, Jridi A, Thulin PC, Zorn M, McKee KE, Mitrovich K, Moretti P, Alshaikh J, Kassavetis P, Cortez MM, Lamotte G. Effect of levodopa on postural blood pressure changes in Parkinson disease: a randomized crossover study. Clin Auton Res. 2024 Feb;34(1):117-124. doi: 10.1007/s10286-024-01024-5.

« Back to 2025 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/carbidopa-levodopa-related-hypotension-in-patients-with-alpha-synucleinopathies/