Varenicline for the treatment of postural and gait dysfunction in Parkinson’s disease (PD)

ABSTRACTObjective:To determine if varenicline is effective for balance in Parkinson’s disease (PD).Methods:This was an investigator-initiated, double-blind, placebo-controlled study. Participants with a clinical diagnosis of PD were randomized to receive varenicline or placebo for eight weeks. After dose escalation, participants took 1mg of drug twice daily until end of study. Patients with severe tremor were excluded. Primary outcome was change on the Berg Balance Scale (BBS) from baseline to eight weeks. The BBS is a fourteen-item measure consisting of basic balance tasks. The study had a secondary, exploratory outcome of change in cognition, measured with the Frontal Assessment Battery (FAB) and the Mini Mental State Exam (MMSE) from baseline to eight weeks. The FAB is a six item measure of executive functioning.Results:Thirty-six participants were randomized (82% men, 100% Caucasian). Average age was 71.0 years (±8.1). Average baseline motor MDS-UPDRS was 34.7 (±11.6). There were no differences between treatment groups on the BBS (F[1,28]=2.85,p =0.10) or FAB (d=0.16,95% CI=[-1.39,1.53]), or MMSE (d=0.81,95%CI=[-0.40,1.40]).Conclusion:The results did not suggest varenicline had an effect on balance in patients with PD. Furthermore, varenicline did not appear to effect cognition. Perhaps if an objective measure of balance had been used in place of the BBS, analysis would show a difference between groups. However, the authors do not recommend further study.Classification of Evidence:This study provides Class III evidence that in PD patients with H&Y stages 2,3, or 4, varenicline does not improve balance as assessed by the BBS.