title: Pharmacokinetics of levodopa in patients with Parkinson disease and motor fluctuations depending on the presence of Helicobacter pylori infection.
abstract: BACKGROUND
  According to recent investigations, the eradication of Helicobacter pylori (H. pylori) may influence levodopa (LD) pharmacokinetics (PK) and improve the motor function of infected patients with Parkinson disease (PD). The aim of this study was to compare PK of LD and its metabolite 3-O-methyldopa (3-OMD), between H. pylori-positive (HP+) and -negative (HP-) patients with PD and motor fluctuations.
  
  
  METHODS
  Patients with the clinical diagnosis of PD, under stable LD therapy, reporting daily motor fluctuations and who had no history of previous eradication treatment were screened for the H. pylori infection with an antigen stool test. Two groups of patients-bacteria-infected and noninfected-matched demographically and clinically, were selected for the examination of PK values. Blood samples were collected after morning oral LD dose. Noncompartmental PK parameters were computed from the LD and 3-OMD plasma concentration-time data.
  
  
  RESULTS
  Interindividual variability was seen in LD absorption curve in both groups. There were no clinically significant differences in PK parameters of LD and 3-OMD. Changes of small magnitude but with possible clinical impact were found according to tmax and Cmax that tended to be lower in HP- patients and AUC0-t that was larger in the HP+ group. The Cmax value of 3-OMD was almost identical in both groups. The HP- group had smaller AUC0-∞t of 3-OMD.
  
  
  CONCLUSIONS
  The H. pylori infection in PD patients with motor fluctuations, despite not significantly influencing PK parameters of LD and 3-OMD, may still have important clinical implications.
authors.affiliation: *Neurology Department, St Adalbert Hospital, Gdansk, Poland; †Neurological and Psychiatric Nursing Department, Medical University of Gdansk, Gdansk, Poland; Departments of ‡Experimental and Clinical Pharmacology and §Pharmacokinetics and Therapeutic Drug Monitoring, Pomeranian Medical University, Szczecin, Poland; and ∥Gastroenterology Department, The Pennine Acute Hospitals NHS Trust, Manchester, UK.
authors.forename: Ewa
authors.initials: E
authors.lastname: Narożańska
authors.forename: Monika
authors.initials: M
authors.lastname: Białecka
authors.forename: Urszula
authors.initials: U
authors.lastname: Adamiak-Giera
authors.forename: Barbara
authors.initials: B
authors.lastname: Gawrońska-Szklarz
authors.forename: Witold
authors.initials: W
authors.lastname: Sołtan
authors.forename: Michał
authors.initials: M
authors.lastname: Schinwelski
authors.forename: Piotr
authors.initials: P
authors.lastname: Robowski
authors.forename: Mariusz H
authors.initials: MH
authors.lastname: Madaliński
authors.forename: Jarosław
authors.initials: J
authors.lastname: Sławek
mesh_terms: D000328:Adult; D000368:Aged; D000978:Antiparkinson Agents / Q000493:pharmacokinetics* / Q000627:therapeutic use; D001545:Benserazide / Q000627:therapeutic use; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives / Q000097:blood; D005215:Fasting; D005260:Female; D016481:Helicobacter Infections / Q000097:blood / Q000150:complications*; D016480:Helicobacter pylori / Q000472:pathogenicity*; D006801:Humans; D007980:Levodopa / Q000493:pharmacokinetics* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000187:drug effects*; D010300:Parkinson Disease / Q000097:blood / Q000150:complications / Q000188:drug therapy; D012720:Severity of Illness Index; D014443:Tyrosine / Q000031:analogs & derivatives
chemical_list: D000978:Antiparkinson Agents; D014443:Tyrosine; D007980:Levodopa; D004295:Dihydroxyphenylalanine; D001545:Benserazide; C008404:3-methoxytyrosine