Table 2.

The DPWG Recommendations for Omeprazole and CYP2C19 Genotype (2018)

PhenotypeActionPharmacist text
CYP2C19 poor metabolizer

No action is required for this gene-drug interaction.

The higher plasma concentration of omeprazole results in an increase in the therapeutic effectiveness, without an increase in the side effects.

CYP2C19 intermediate metabolizer

No action is required for this gene-drug interaction.

The higher plasma concentration of omeprazole results in an increase in the therapeutic effectiveness, without an increase in the side effects.

CYP2C19 ultrarapid metabolizerFor Helicobacter pylori eradication therapy:
  • use a 3-fold higher dose
  • advise the individual to report persisting symptoms of dyspepsia
The genetic variation may lead to a reduced omeprazole plasma concentration and therefore reduced effectiveness.
Other indications
  • be alerted to reduced effectiveness
  • if necessary, use a 3-fold higher dose
  • advise the individual to contact their doctor if symptoms of dyspepsia persist

Please see Therapeutic Recommendations based on Genotype for more information from DPWG. This Dutch Pharmacogenetics Working Group (DPWG) table is adapted from (2).

From: Omeprazole Therapy and CYP2C19 Genotype

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