The pharmacodynamic effect of omeprazole 10 mg and 20 mg once daily in patients with nonerosive reflux disease in Japan.
BACKGROUND
To evaluate the pharmacodynamic effect, efficacy, and safety of omeprazole 10 mg and 20 mg once daily in patients with nonerosive reflux disease (NERD) in Japan.


METHODS
A total of 37 patients were randomized to omeprazole 10 mg or omeprazole 20 mg once daily for 4 weeks. Eligible patients had a history of moderate-to-severe heartburn for 2 days or more per week during the last 1 month or longer prior to the study screening, grade M or grade N on Hoshihara's modification of the Los Angeles classification (i.e., no sign of mucosal break on esophagogastroduodenoscopy), and heartburn episodes for 2 days or more per week during the last week of the observation period while taking antacids. Ambulatory 24-h intraesophageal pH was monitored on the day before treatment and on the last day of treatment. The occurrence of a heartburn episode was recorded during pH monitoring. The primary endpoint was the change in the percentage of time with intraesophageal pH < 4 during the 24-h period before and after omeprazole treatment.


RESULTS
Both omeprazole 10 mg and omeprazole 20 mg once daily reduced the percentage of time with intraesophageal pH < 4. The percentage reduction in time with intraesophageal pH < 4 after treatment with omeprazole was associated with a reduced number of heartburn episodes. Patients with grade M or grade N esophagus had similar pH profiles and NERD characteristics (e.g., pH holding time, symptom index) and comparable responses to omeprazole. No serious, drug-related adverse events were reported.


CONCLUSIONS
Omeprazole 10 mg or 20 mg reduces the percentage of time with intraesophageal pH < 4, is efficacious, and is well tolerated in patients with NERD in Japan, regardless of the patient's endoscopic classification.
Kinoshita
Yoshikazu
Y
Department of Gastroenterology and Hepatology, Shimane University School of Medicine, Izumo, 693-8501, Japan.
Kobayashi
Takeaki
T
Kato
Mototsugu
M
Asahina
Kan
K
Haruma
Ken
K
Shimatani
Tomohiko
T
Inoue
Shuji
S
Kabemura
Teppei
T
Kurosawa
Susumu
S
Kuwayama
Hajime
H
Ashida
Kiyoshi
K
Hirayama
Michiaki
M
Kiyama
Satoshi
S
Yamamoto
Munemitsu
M
Suzuki
Junichi
J
Suzuki
Hiroyuki
H
Matsumoto
Katsuhiko
K
Aoshima
Masaru
M
D000328:Adult; D000368:Aged; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D005764:Gastroesophageal Reflux / Q000188:drug therapy*; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D054328:Proton Pump Inhibitors
D054328:Proton Pump Inhibitors; D009853:Omeprazole