**3.2 Pharmacotherapy**

PPI are the mainstay medical treatment for GERD, it is initially given as activephase therapy, with continuous use to improve and heal the mucosal erosion, then follows by on-demand therapy phase for maintenance [6, 36]. However, there are still scarce yet inconsistent data available regarding the influence of obesity to the response of PPI treatment for GERD patients. Peura *et al.* conducted a study that found the efficacy of PPI therapy on the reduction in heartburn symptoms frequency and severity was similar across BMI categories, in both NERD and erosive esophagitis patients [42]. However, when the therapeutic target of the initial phase of PPI therapy is based on the sustained symptomatic response (SSR, *i.e.* free from reflux symptoms for the last 7 days), Sheu *et al.* found a lower SSR rates in the overweight and obese groups, compared to control group [43]. During maintenance therapy, the mean number of PPI tablets used was significantly higher in the overweight and obese groups than in the control group [43]. This findings was further studied by Chen *et al.* to determine whether double-dose PPI can elevate the SSR rate for overweight or obese patients [44]. They also checked whether different genotypes of CYP2C19 would affect the SSR rates. This study found a higher rates of SSR in the doubledose PPI group than in the standard group. Treatment with double-dosed PPI also improved the cumulative rates of SSR in the extensive metabolizer group [44].

Pharmacotherapy in obesity is indicated in patients with obesity-associated complications that have failed to achieve a healthy weight by implementing a low-calorie diet and regular exercise [45]. Less coverage of antiobesity drugs by insurance and their high cost has limits patients' choices. In addition, until the present time there is no available data that describe the impact of using antiobesity to achieve weight loss in patients with GERD.
