The efficacy of extended-interval dosing of omeprazole in keeping gastroesophageal reflux disease patients symptom free.
The potential economic advantage of alternate-day therapy for GERD maintenance must be weighed against the potential cost of failure before it can be widely instituted. The studies presented have helped develop a clinical picture of the patients who may benefit from alternate-day therapy without risk of complications or potential increases in management costs. Bank et al., reporting on a group of patients, found that patients with Grade II-IV disease had a 61% success rate at two to eight years. Bank defined success as both maintenance of endoscopic healing and symptom control. Ladas et al. found a 66.7% success rate defined as clinical and endoscopic remission in Grades II-III disease. Kurucar et al. monitored symptom control and esophageal complications in his patients and found the regimen to have a 26% success rate in Grades III-IV disease. Lind et al. found that 83% of patients could remain symptom free with on-demand therapy if they were endoscopy-negative at baseline. The results of the Mantides et al. study are important because they imply that alternate-day omeprazole therapy may be more effective than alternatives for step-down treatment, such as ranitidine or cisapride. Furthermore, patients can be educated to increase their frequency of use if symptoms should arise. Not only does this give the patient a sense of self-empowerment over his or her disease state, but it avoids the cost of switching to a PPI due to failure with an H2RA or a motility agent. Alternate-day use of omeprazole should be attempted only during the maintenance phase of GERD therapy. Patients requiring >20 mg/d to achieve healing appeared to be poor candidates for alternate-day omeprazole maintenance therapy. Based on available studies, it would seem that patients with Grades 0-II GERD would benefit most from alternate-day therapy. A role for alternate-day therapy in Grades III-IV is apparent from the results presented but requires greater caution in view of the differing success rates (26-61%) in various studies. With Grades II-III esophagitis, a mean 24-hour gastric pH >6 and a gastric pH <4 less than 10% of the time during the initial healing phase with omeprazole 20 mg/d appeared to be associated with success on alternate-day therapy. Evidence that all marketed PPIs have similar success is not available and should not be extrapolated from the data presented. Evidence that downward dosage adjustments of PPIs versus extending dosage intervals are effective in the maintenance of GERD should be recognized. Lansoprazole has been approved for treating erosive esophagitis at 30 mg/d, with the maintenance dose established at 15 mg/d. Studies showing that lansoprazole 15 mg/d is more effective than alternate-day therapy with lansoprazole 30 mg exist, although similar studies with omeprazole have not been performed. The abstracts describing the use of alternate-day omeprazole accounted for all enrollees and included endoscopic grading or pH monitoring to document disease severity at baseline. Most also included these same objective measures as end points in combination with symptom control. This strengthens the data since the positive predictive value of typical symptoms is variable. However, there are also several significant limitations. Abstracts provide only limited information on methods. All studies other than Lind et al. lacked randomization. This study was also the only one that blinded patients to their treatment. Sample sizes for the majority of the trials were quite small. Statistical analyses were not performed on any of the trial results with the exception of the trial by Lind et al. In light of the lack of evidence of statistical significance as well as study design flaws, conclusions should be drawn cautiously. Larger well-designed trials looking at both the efficacy and cost-effectiveness of alternate day omeprazole are required before a definitive recommendation can be made.
Bieszk
N
N
Wayne State University, Detroit, MI, USA.
Kale-Pradhan
P B
PB
D002986:Clinical Trials as Topic; D004334:Drug Administration Schedule; D004791:Enzyme Inhibitors / Q000008:administration & dosage*; D005764:Gastroesophageal Reflux / Q000191:economics / Q000517:prevention & control*; D006801:Humans; D009853:Omeprazole / Q000008:administration & dosage*
D004791:Enzyme Inhibitors; D009853:Omeprazole