Helicobacter pylori eradication and L-dopa absorption in patients with PD and motor fluctuations

Objective: To investigate if Helicobacter pylori (HP) eradication could make an effective and long-lasting improvement in the pharmacokinetic and clinical response to L-dopa in patients with Parkinson disease (PD) and motor fluctuations. Methods: In a group of 34 HP-infected, motor-fluctuating patients with PD, the short-term (1-week) and long-term (3-month) beneficial effect of HP eradication (n=17) was investigated in a double-blind fashion in comparison with a generic antioxidant treatment (n=17), by means of pharmacokinetic, clinical, and gastrointestinal assessments. Results were compared with placebo treatment. Results: Differently from the antioxidant-treated patients, the HP-eradicated patients showed a significant increase of L-dopa absorption, which was coupled with a significant improvement of clinical disability and with a prolonged on-time duration, whereas gastritis/duodenitis scores significantly decreased in line with a better L-dopa pharmacokinetics. Conclusions: These data demonstrate a reversible Helicobacter pylori (HP)-induced interference with L-dopa clinical response related to the impaired drug absorption, probably due to active gastroduodenitis. Therefore, the authors suggest that HP eradication may improve the clinical status of infected patients with Parkinson disease and motor fluctuations by modifying L-dopa pharmacokinetics.