tadalafil for Parkinson's disease

Inclusion criteria

• {"criterion_text":"- Diagnosis of early-stage Parkinson’s disease, with no limitations in daily functioning that would necessitate symptomatic treatment\n- No prior medication for Parkinson’s disease.\n- Normal blood pressure (between >90/60 mm Hg and <120/80 mm Hg).\n- Age older than 18 years.\n- Informed consent and comply with the study protocol.\n- Understand the Dutch language."}

Exclusion criteria

• {"criterion_text":"- Currently taking PDE-inhibitors for erectile dysfunction.\n- (unstable) Cardiovascular and cerebrovascular disease.\n- Unilateral blindness, hereditary retinal disorders, or increased risk of blindness.\n- Unilateral deafness or history of severe hearing loss dependent upon hearing aid(s).\n- Multisystem atrophy (MSA).\n- Abnormal electrocardiogram (ECG).\n- Orthostatic hypotension: a decrease in systolic blood pressure ≥ 20 mmHg, or a decrease in diastolic blood pressure ≥ 10 mmHg.\n- Immunocompromised.\n- Mild cognitive impairment (MCI) or dementia.\n- Pregnancy and breastfeeding.\n- Legally incompetent adults.\n- Clinically significant penile deformity.\n- Concurrent nitrate, nitric oxide donors, guanylate cyclase, nicorandil, theophylline alpha-blocker, cytochrome P-450 3A4 (CYP3A4) inhibitor/inducer, or prostacyclin analog use.\n- Suspicion of or a known history of renal (eGFR level < 80 ml/min) or hepatic insufficiency.\n- Significant alcohol or drug abuse."}

Primary endpoints

• {"endpoint_text":"- Change in motor symptoms using the MDS-UPDRS part III from baseline to two weeks after daily tadalafil administration.","definition_or_measurement_approach":"Change in motor symptoms measured by the MDS-UPDRS part III score from baseline to two weeks after daily tadalafil administration."}

Secondary endpoints

• {"endpoint_text":"- All adverse events will be recorded during follow-up. The following specific side effects will be assessed (yes/no): 1) Headache, 2) Dyspepsia, 3) Back pain, 4) Muscle pain, 5) Flushing, 6) Nasal congestion, 7) Unwanted erections, and 8) Changes in libido. Blood pressure (mmHg) and heart rate (bpm) will be measured at baseline and after two weeks.","definition_or_measurement_approach":"All adverse events recorded during follow-up; specific symptoms assessed as yes/no. Blood pressure (mmHg) and heart rate (bpm) measured at baseline and after two weeks."}
• {"endpoint_text":"- Participant’s evaluation of the burden of the treatment after two weeks follow-up will be measured with a five-point Likert-type item.","definition_or_measurement_approach":"Participant-reported treatment burden measured using a five-point Likert-type item at two weeks."}
• {"endpoint_text":"- Participant’s satisfaction on the outcome of treatment after two weeks follow-up will be measured with a five-point Likert scale.","definition_or_measurement_approach":"Participant-reported satisfaction measured using a five-point Likert scale at two weeks."}

Netherlands

Earliest CTIS Part Ii Submission Date

15-12-2025

Latest Decision Or Authorization Date

05-01-2026

Processing Time Days

21

Number Of Sites

1

Number Of Participants

20

Primary sponsor

Full Name

Amsterdam UMC Stichting

Organisation Type

Patient organisation/association

Country Of Registered Address

Netherlands