From the Research
Prozac (fluoxetine) and omeprazole may interact, potentially increasing fluoxetine levels in the body due to omeprazole's inhibition of the CYP2C19 enzyme, which is also inhibited by fluoxetine itself, as reported in the most recent study 1. This interaction can lead to increased side effects of Prozac, such as nausea, headache, insomnia, anxiety, or serotonin syndrome.
- The mechanism of this interaction is complex, involving the inhibition of CYP2D6 and CYP2C19 enzymes by fluoxetine and its active metabolite, norfluoxetine, as well as the potential for omeprazole to inhibit these enzymes, leading to slower breakdown of fluoxetine 1.
- Patients taking both medications should be monitored closely for signs of increased fluoxetine levels, and dosage adjustments may be necessary to minimize the risk of adverse effects.
- It is essential for patients to inform their healthcare provider about all medications they are taking and report any unusual symptoms, as this interaction can be more significant in people who are poor metabolizers of CYP2C19 due to genetic factors 1.
- The study published in 2021 1 provides the most recent and highest quality evidence on this topic, and its findings should be prioritized when assessing the potential interaction between Prozac and omeprazole.
- Never stop either medication abruptly without medical guidance, as this can lead to serious consequences, including withdrawal symptoms or increased risk of adverse effects.
- Healthcare providers should be aware of the potential for drug-drug interactions involving fluoxetine and omeprazole and take steps to minimize the risk of adverse effects, such as monitoring patients closely and adjusting dosages as needed 1.