Understanding Dexilant and Its Mechanism
Dexilant, with the active ingredient dexlansoprazole, is a proton pump inhibitor (PPI) used to treat conditions related to stomach acid, such as gastroesophageal reflux disease (GERD) and erosive esophagitis [1.2.2]. It works by specifically blocking the final step in acid production in the stomach's parietal cells [1.12.1]. By inhibiting this 'proton pump' (the (H+,K+)-ATPase enzyme), Dexilant significantly reduces the amount of acid in the stomach, which helps alleviate symptoms like heartburn and allows the esophagus to heal [1.12.1, 1.12.2].
However, this change in stomach acidity is a primary reason for many drug interactions. Some drugs require an acidic environment to be absorbed properly by the body [1.4.1]. By creating a more alkaline environment, Dexilant can decrease the absorption and effectiveness of these medications. Additionally, Dexilant is metabolized by enzymes in the liver, primarily CYP2C19 and CYP3A4 [1.3.1]. It can compete with or affect other drugs that use these same enzyme pathways, potentially leading to increased or decreased levels of those drugs in the bloodstream.
Major Drug Interactions to Avoid
Certain medications should not be taken with Dexilant due to the high risk of severe adverse effects or complete loss of therapeutic efficacy.
- Certain HIV Medications: The use of Dexilant with rilpivirine-containing products (Edurant, Cabenuva, Juluca, Odefsey) is contraindicated [1.3.2, 1.7.1]. Dexilant significantly lowers the concentration of rilpivirine in the blood, making it ineffective at treating HIV [1.7.1, 1.7.2]. Similar concerns exist for atazanavir (Reyataz) and nelfinavir (Viracept), where co-administration is not recommended because Dexilant can lead to a loss of their therapeutic effect and promote drug resistance [1.3.3, 1.7.4].
- St. John's Wort: This herbal supplement, often used for depression, can speed up the breakdown of Dexilant in the body. This action can lead to low levels of Dexilant, rendering it ineffective for treating your condition [1.9.1, 1.9.3].
Significant and Moderate Interactions Requiring Caution
Many common medications can interact with Dexilant, requiring close monitoring or dose adjustments by a healthcare provider. These interactions can either increase the risk of side effects from the other drug or reduce its effectiveness.
- Warfarin (Jantoven): Co-administration of this blood thinner with Dexilant may increase the International Normalized Ratio (INR) and prothrombin time, which can lead to a higher risk of abnormal bleeding [1.5.2, 1.5.3]. Patients on this combination require close monitoring of their INR [1.5.1].
- Methotrexate: Used for treating certain cancers and autoimmune diseases like rheumatoid arthritis, methotrexate levels can become elevated and prolonged when taken with PPIs like Dexilant [1.6.1, 1.6.4]. This increases the risk of methotrexate toxicity, which can cause side effects like mouth ulcers, infection, and bleeding [1.6.3]. For patients on high-dose methotrexate, a temporary withdrawal of Dexilant may be considered [1.6.4].
- Certain Antifungals: Medications like ketoconazole and itraconazole require stomach acid for absorption. Dexilant reduces their absorption, potentially making them less effective at treating fungal infections [1.2.1, 1.4.1].
- Digoxin: This heart medication can have an increased effect when taken with Dexilant, raising the risk of digoxin-related side effects [1.2.3]. Low magnesium levels caused by long-term Dexilant use can also increase the risk of digoxin toxicity [1.3.2].
- Tacrolimus: An immunosuppressant used in transplant patients, its blood concentrations can be increased when taken with Dexilant, raising the risk of side effects [1.2.1].
- Iron Supplements: Dexilant can reduce the absorption of iron from supplements because iron absorption is dependent on an acidic environment [1.13.2, 1.13.3].
Comparison of Dexilant Interactions
| Interacting Drug Class | Example(s) | Potential Effect of Interaction | Management Recommendation |
|---|---|---|---|
| HIV Antiretrovirals | Rilpivirine, Atazanavir | Decreased antiretroviral effectiveness, risk of drug resistance [1.7.1, 1.7.4]. | Co-administration with rilpivirine is contraindicated [1.3.2]. Avoid use with atazanavir [1.3.3]. |
| Anticoagulants | Warfarin | Increased risk of bleeding [1.5.2]. | Monitor INR and prothrombin time closely [1.5.3]. |
| Chemotherapy/Immunomodulators | Methotrexate, Mycophenolate Mofetil | Increased methotrexate toxicity; decreased mycophenolate effectiveness [1.2.1, 1.6.3]. | Consider temporary withdrawal of Dexilant for high-dose methotrexate [1.6.4]. Monitor patient. |
| Antifungals (Azoles) | Ketoconazole, Itraconazole | Decreased antifungal effectiveness [1.2.1]. | Monitor for clinical response; may need alternative medication. |
| Cardiac Glycosides | Digoxin | Increased risk of digoxin toxicity [1.2.3]. | Monitor digoxin levels and for signs of toxicity [1.3.2]. |
| Herbal Supplements | St. John's Wort | Decreased Dexilant effectiveness [1.9.1]. | Avoid concomitant use [1.9.1]. |
| Mineral Supplements | Iron Salts | Decreased iron absorption [1.13.3]. | Monitor iron levels, especially with long-term use. |
Lifestyle and Other Considerations
While alcohol does not directly interact with the Dexilant delayed-release capsules, it is advised to avoid alcohol when taking the orally disintegrating tablet form (SoluTab), as it could alter the medication's release [1.10.2, 1.10.3]. Long-term use of Dexilant (over three years) has also been linked to vitamin B12 deficiency and low magnesium levels, as stomach acid is necessary for their absorption [1.2.3, 1.3.2]. Your doctor may recommend monitoring these levels.
Conclusion
To ensure both the safety and effectiveness of your treatment, it is essential to be aware of what you can not take with Dexilant. The list of potential interactions is extensive, ranging from prescription medications for serious conditions like HIV and cancer to common over-the-counter supplements such as iron and St. John's wort. Always provide your doctor and pharmacist with a complete list of all medications, supplements, and herbal products you are taking. Never start or stop a medication without consulting your healthcare provider, who can help you navigate these interactions and find the safest, most effective treatment plan for your condition.
For more detailed information, you can consult the official Dexilant prescribing information on Drugs.com [1.7.4].
