Background: Gastroesophageal reflux disease (GERD) is common in patients with asthma, but the target population for antireflux treatment, are not precisely defined.
The purpose of the study: To assess the effect of the proton pump inhibitor omeprazole and prokinetic domperidone on cough frequency, in patients with stable asthma of different severity (persistent mild to severe asthma) with chronic cough.
Methods: In this case – control study, 45 adult stable asthmatics, received omeprazole 40 mg twice daily, with domperidone 5 mg half an hour before meal three times daily for 4 weeks, and followed for cough frequency (score of 5[no=0, rare =1, usual =2, common =3, frequent =4] ) according to patient daily records . According to GERD esophageal symptoms, subjects were divided into two matched groups: with GERD group (25 patients) and without GERD group (20 patients).
Main Results: There were statistically highly significant (P < .0001) improvements in cough frequency, in the overall study population (35/45patients [77.8%], Z=-5.11), and in both groups (GERD19/25patients [76. %] Z= -3.72, without GERD 16/20 patients [80%] Z= -3.64).
But there was no statistically significant difference, as regard cough frequency improvement, between groups.
According to cough frequency score ≥ 2, the probability (the positive predictive value) that a subject has GERD -assessed by cough improvement on antireflux treatment- was 85.7% in the 45 patients, 88.23% in GERD group, and 81.8% in without GERD group.
Conclusions: omeprazole combined with domperidone improved cough frequency in 45 subjects with stable asthma either with or without GERD esophageal symptoms, which makes the possibility of hidden GERD (without esophageal symptoms) high in patients without GERD esophageal symptoms; the high positive predictive value of cough frequency
(≥ 2) in predicting GERD in such patients, nominate it as a possible guide for prescribing antireflux treatment in such stable asthmatics, even in patients without esophageal GERD symptoms.