CYP2C19 Genotype Predictor of Gastric Acid Suppression

Mayo Clinic

Status and phase: Withdrawn; Early Phase 1

Conditions: Esophagitis

Treatments: Drug: Omeprazole

Study type: Interventional

Funder types: Other

Identifiers

NCT01824199

12-008053

Details and patient eligibility

About

If CYP2C19 genotype can predict the efficacy of healing erosive esophagitis and gastric acid secretion in patients taking once a day omeprazole.

Full description

Proton pump inhibitors are metabolized through the CYP2C19 hepatic enzyme system. Several variant genotypes of this enzyme exist which may lead to decreased, normal or increased metabolism of the proton pump inhibitor. With alteration of metabolism, the degree of gastric acid suppression achieved and efficacy in treating reflux could be affected. For example, Asian populations who have low activity of CYP2C19, commonly need lower doses of proton pump inhibitors to manage gastroesophageal reflux because of more sustained blood levels and availability of the drug. Theoretically, those patients who are rapid metabolizers would receive less effective treatment with proton pump inhibitors

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Age 18 or older
• Have either mild-to-moderate Los Angeles (LA) Classification System grade B, moderately severe LA grade C, or severe LA grade D erosive reflux esophagitis
• Or patients having a clinically indicated pH/impedance monitoring on proton pump inhibitor therapy for indications of gastroesophageal reflux disease.

Exclusion criteria

• Neoplasm of the esophagus or stomach
• Use of drugs that interfere with CYP2C19 metabolism Diazepam, phenytoin, amitriptyline, clomipramine, clopidogrel Cyclophosphamide, progesterone, fluoxetine, fluvoxamine, ketoconazole Lansoprazole, omeprazole, ticlopidine
• Evidence of active H. pylori infection
• Inability to read due to: Blindness, cognitive dysfunction, or English language illiteracy
• Disorders which predispose to unreliable responses such as Schizophrenia, Alzheimer's disease or significant memory loss

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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0 participants in 1 patient group

Omeprazole

Experimental group

Description:

Patients will undergo whole blood testing for CYP2C19 genotype and will be started on omeprazole 40 mg once daily in the morning 30 minutes before breakfast. The Mayo Dysphasia Questionnaire 30 day (MDQ-30day) will be used during the study. At the end of 8 weeks, patients will undergo dual probe pH/impedance testing on therapy and a clinically indicated endoscopy to rule out Barrett's esophagus and assess healing. CYP2C19 genotyping will be performed in the Mayo laboratory.

Treatment:

Drug: Omeprazole