Understanding Voquezna's Role in Drug Interactions
Voquezna, with the active ingredient vonoprazan, treats gastroesophageal reflux disease (GERD) and H. pylori infections. It is available as a single agent or in combination as Voquezna Dual Pak (with amoxicillin) and Voquezna Triple Pak (with amoxicillin and clarithromycin). Each formulation has different interaction profiles. Vonoprazan affects metabolic enzymes, while the clarithromycin in the Triple Pak significantly increases the risk of interactions, including some that can be fatal.
Interactions affecting Voquezna's primary action
Voquezna reduces stomach acid by blocking potassium channels. This can alter the absorption of other drugs that need an acidic environment to work properly. Additionally, other substances can affect how quickly Voquezna is metabolized, impacting its effectiveness.
Drugs to Avoid with Voquezna (Monotherapy)
- Rilpivirine-containing products: Contraindicated with all Voquezna formulations due to decreased effectiveness of this HIV medication and potential drug resistance.
- Certain HIV medications: Avoid with atazanavir and nelfinavir due to reduced absorption.
- Certain antifungals: Avoid with itraconazole and ketoconazole due to reduced absorption.
- Certain anti-cancer (TKI) drugs: Avoid with pH-dependent TKIs like erlotinib and dasatinib due to decreased absorption.
- Strong CYP3A4 inducers: Substances like carbamazepine, phenytoin, and St. John's wort can decrease Voquezna's effectiveness.
- Cilostazol: Increased risk of side effects when taken with Voquezna.
- Citalopram: Increased risk of side effects due to higher citalopram levels.
Specific Warnings and Contraindications for Voquezna Triple Pak
The clarithromycin in the Triple Pak is a strong CYP3A4 inhibitor, leading to a wider range of serious interactions.
Life-threatening and serious interactions
- Colchicine: Contraindicated with clarithromycin in patients with kidney or liver impairment due to risk of fatal toxicity.
- Certain statins: Contraindicated with lovastatin and simvastatin due to increased risk of myopathy and rhabdomyolysis.
- Pimozide: Contraindicated with clarithromycin due to risk of dangerous cardiac arrhythmias.
- Ergot alkaloids: Contraindicated with clarithromycin.
- Lurasidone: Contraindicated with clarithromycin due to increased exposure and adverse effects.
Other serious interactions with the Triple Pak
- Hypoglycemic agents/Insulin: Increased risk of hypoglycemia.
- Calcium channel blockers: Risk of serious adverse reactions like kidney injury and hypotension with certain drugs.
- Warfarin: Increased risk of serious bleeding.
- Benzodiazepines: Increased and prolonged sedative effects.
Comparison of Drug Interactions by Formulation
| Drug Class / Example | Interaction with Voquezna (vonoprazan only) | Interaction with Voquezna Triple Pak (vonoprazan + clarithromycin) |
|---|---|---|
| HIV Medications | Reduces effectiveness (rilpivirine, atazanavir, nelfinavir) | Rilpivirine is contraindicated. Atazanavir and nelfinavir interactions apply. |
| Antifungals | Reduces absorption and effectiveness (itraconazole, ketoconazole) | Reduces absorption and effectiveness (itraconazole, ketoconazole). |
| Statins | No known specific interaction | Contraindicated for lovastatin and simvastatin due to myopathy risk. Caution with atorvastatin. |
| Citalopram | Increases citalopram levels, raising side effect risk | Increases citalopram levels due to vonoprazan effect, potentially compounded by clarithromycin. |
| Colchicine | No known specific interaction | Contraindicated in patients with renal or hepatic impairment due to fatal toxicity risk. |
| Pimozide | No known specific interaction | Contraindicated due to risk of serious cardiac arrhythmias. |
| St. John's Wort | Decreases vonoprazan effectiveness | Decreases vonoprazan effectiveness. |
Herbal Supplements and Diagnostic Tests
St. John's wort can decrease Voquezna's efficacy. Always inform your doctor about all supplements. Voquezna can also interfere with certain diagnostic tests like the chromogranin A (CgA) test for neuroendocrine tumors, requiring temporary discontinuation before testing.
How to Manage Safe Medication Use with Voquezna
To use Voquezna safely:
- Provide a complete list: Share all medications, including OTC drugs, vitamins, and supplements, with your healthcare provider and pharmacist.
- Read the label: Review prescribing information, especially for combination paks.
- Monitor for symptoms: Watch for signs of altered drug effects or increased side effects.
- Discuss underlying conditions: Inform your doctor about conditions like liver or kidney problems.
Conclusion
Knowing what not to take with Voquezna depends on the specific formulation. While monotherapy interactions involve gastric pH and enzymes, the Triple Pak's clarithromycin component adds potentially fatal contraindications with drugs like certain statins, colchicine, and pimozide. Discussing your full medication list with your healthcare team is vital for safe and effective treatment.
Consult the full prescribing information for Voquezna for a complete list of interactions and warnings.
