Proton pump inhibitors (drug interactions)
Proton pump inhibitors (PPIs) are medications commonly used to reduce stomach acid levels, providing relief from conditions such as gastroesophageal reflux disease (GERD) and peptic ulcers. However, they can interact with various substances, which may affect their efficacy or lead to adverse effects. One significant interaction occurs with St. John's wort, which may lower the effectiveness of PPIs like omeprazole by reducing their levels in the body. Additionally, long-term use of PPIs can hinder the absorption of essential nutrients, notably vitamin B12 and folate, potentially leading to deficiencies.
Minerals such as iron and zinc may also be less efficiently absorbed due to reduced stomach acidity. Other herbal supplements, like ginkgo biloba and kava, can pose risks when combined with PPIs, with ginkgo increasing bleeding risks and kava enhancing sedative effects. Furthermore, certain prescription medications, particularly antifungals and those metabolized by liver enzymes, may have altered absorption or effectiveness when taken alongside PPIs. As such, it is crucial for individuals using PPIs to consult healthcare providers before starting any new supplements or medications to avoid harmful interactions.
Subject Terms
Proton pump inhibitors (drug interactions)
- DEFINITION: Drugs used to reduce levels of stomach acid.
- INTERACTIONS: Folate, ginkgo biloba, kava, minerals, prescription medications, St. John’s wort, vitamin E, vitamin B12
- DRUGS IN THIS FAMILY: Lansoprazole (Prevacid), omeprazole (Prilosec)
St. John’s Wort
Effect: Possible Harmful Interactions
The herb St. John’s wort is known to interact with numerous drugs. There are two potential harmful interactions between St. John’s wort and proton pump inhibitors.
One study found that using St. John’s wort dramatically decreases levels of omeprazole (such as Prilosec) in the body. This would be expected to lead to markedly reduced efficacy.
The other potential risk is more theoretical. When taken in excess, the herb St. John’s wort can increase the risk of sunburn. Some evidence hints that proton pump inhibitors might increase this risk.
Vitamin B12
Effect: Supplementation Likely Helpful
Vitamin B12 deficiency is a concern with all drugs that reduce stomach acidity. In food, proteins always accompany vitamin B12, which must be separated from them before it can begin to be absorbed. Following separation, B12 is attached to a substance called intrinsic factor, which allows B12 to be absorbed in the intestines.
Stomach acid plays a role in this separation. If one does not have enough stomach acid, the process of freeing vitamin B12 from protein so that it can be bound to intrinsic factor may be impaired.
Studies suggest that treatment with proton pump inhibitors might significantly reduce the absorption of vitamin B12. There is some evidence that cranberry juice might increase B12 absorption in persons taking proton pump inhibitors, possibly because the juice is somewhat acidic.
Folate
Effect: Supplementation Possibly Helpful
Research on related medications suggests that proton pump inhibitors may slightly reduce the body’s folate absorption. The decrease in folate absorption should be slight, but because folate deficiency is quite common and potentially harmful, taking extra folate might make sense as insurance.
Minerals
Effect: Supplementation Possibly Helpful
By reducing stomach acid levels, proton pump inhibitors might interfere with iron, zinc, and perhaps other mineral absorption. Taking mineral supplements to meet the US Dietary Reference Intake (formerly known as the Recommended Dietary Allowance) levels for these nutrients should help.
Other Interactions
There are several additional interactions one should be aware of when taking proton pump inhibitors. Ginkgo biloba increases the risk of bleeding when taken with proton pump inhibitors. Kava and other herbs with sedative properties may enhance those found in proton pump inhibitors. Creating a comprehensive list of all herbs and supplements that could potentially interfere with proton pump inhibitors would be challenging, so patients are advised to consult their healthcare providers before combining herbs and supplements with proton pump inhibitors. Finally, several prescription medications can cause interactions with proton pump inhibitors. Proton pump inhibitors can affect the proper absorption of prescription medications that rely on stomach acid to be absorbed, such as antifungal medications. Drugs that are metabolized by liver enzymes should also be avoided. Combining proton pump inhibitors with methotrexate, a drug prescribed for cancer and autoimmune diseases, can lead to toxic levels of methotrexate in the body.
Bibliography
Aymard, J. P., et al. "Haematological Adverse Effects of Histamine H2-Receptor Antagonists." Medical Toxicology and Adverse Drug Experience, vol. 3, 1988, pp. 430-448.
Ahmed, Abdelwahab, and John O. Clarke. "Proton Pump Inhibitors (PPI) - StatPearls." NCBI, 1 May 2023, www.ncbi.nlm.nih.gov/books/NBK557385. Accessed 10 Oct. 2024.
Kinoshita, Yoshikazu, et al. "Advantages and Disadvantages of Long-term Proton Pump Inhibitor Use." Journal of Neurogastroenterology and Motility, vol. 24, no. 2, 2018, pp. 182-196, doi.org/10.5056/jnm18001. Accessed 10 Oct. 2024.
Meriggi, Fausto. "Controversial Link Between Proton Pump Inhibitors and Anticancer Agents: A Review of the Literature." Tumori Journal, vol. 108, no. 3, 2022, pp. 204-212, DOI: 10.1177/03008916211025091. Accessed 20 Dec. 2022.
Mirossay, A., et al. "Potentiation of Hypericin and Hypocrellin-Induced Phototoxicity by Omeprazole." Phytomedicine, vol. 6, 1999, pp. 311-317.
Tan, Charlie M., and David N. Juurlink. "Navigating Drug Interactions with Proton Pump Inhibitors." JAMA Network Open, vol. 7, no. 7, 2024, p. e2419818, doi.org/10.1001/jamanetworkopen.2024.19818. Accessed 10 Oct. 2024.
Wang, L. S., et al. "St. John’s Wort Induces Both Cytochrome P450 3a4-Catalyzed Sulfoxidation and 2c19-Dependent Hydroxylation of Omeprazole." Clinical Pharmacology and Therapeutics, vol. 75, 2004, pp. 191-197.