Title: Clinical Impact of Nicotine in Parkinson’s Disease: Evidence from Randomized Controlled Studies
Authors: Jamir Pitton Rissardo, Jorge Patino, Ana Leticia Fornari Caprara, Andrew McGarry, Ian Walker
Conference: 2026 International Congress of Parkinson's Disease, Seoul, Korea
Objective
To evaluate the effects of nicotine versus placebo in Parkinson’s disease (PD).
Background
Nicotine may influence dopaminergic and non‑dopaminergic pathways relevant to PD. While preclinical data suggest neuroprotective benefits, clinical trial results have been inconsistent.
Design/Methods
A meta‑analysis was conducted using PubMed‑indexed randomized controlled trials (RCTs) comparing nicotine (oral, transdermal patch, dietary) with placebo in PD. Outcomes included motor severity (MDS UPDRS‑III or equivalent), MDS UPDRS‑II, PDQ‑39/PDQ‑8, LEDD (levodopa equivalent daily dose), and adverse events. Subgroup analyses considered treatment duration (<12 weeks, 12–40 weeks, >40 weeks) and dose. Continuous outcomes were pooled using SMD and MD as appropriate. Random‑effects models with REML were used.
Results
Six studies, including 389 participants (active=203 experimental, control=186), were analyzed. Nicotine did not significantly improve motor outcomes (SMD −0.16; 95% CI −0.76 to 0.43; I² = 85%) [Figure 1] or functional disability (MD −0.65; 95% CI −1.77 to 0.47; I² = 0%). Quality‑of‑life measures showed a small but significant benefit favoring nicotine (SMD −0.26; 95% CI −0.44 to −0.07; I² = 0%) [Figure 2]. LEDD changes were nonsignificant (MD −114.40 mg; 95% CI −258.82 to 30.02; I² = 73%) [Figure 3]. Serious adverse events did not differ significantly (RR 1.97; 95% CI 0.97–4.01; I² = 0%), but total adverse events were more common with nicotine (RR 1.51; 95% CI 1.21–1.88). Nicotine increased risks of nausea (RR 3.40; 95% CI 1.81–6.39) and dizziness (RR 1.80; 95% CI 1.06–3.05), while headache, dry mouth, and palpitations showed nonsignificant associations.
Conclusions
Nicotine did not improve motor symptoms, disability, or LEDD, though it provided a small quality‑of‑life benefit. Adverse events, particularly nausea and dizziness, were more frequent. Current evidence does not support nicotine as a symptomatic therapy for PD.
Citation
Rissardo JP, Patino J, Caprara AL, McGarry A, Walker I. Clinical Impact of Nicotine in Parkinson’s Disease: Evidence from Randomized Controlled Studies. Mov Disord 2026;41(Suppl_1):S1201-S1202.
Figure 1. Forest plot of pooled SMD of motor outcomes.
Figure 2. Forest plot of pooled SMD of quality of life outcomes.
Figure 3. Forest plot of pooled MD of LEDD.