Veppanu (vepdegestrant) is used to treat certain types of breast cancer. While Veppanu can slow the rate at which cancer advances in some people, it can also interact with other medicines and substances.
An interaction occurs when one substance changes how a medicine affects the body. Understanding these drug interactions can help lower the risk of side effects, ensure your medicine works well, and avoid unsafe combinations.
This article does not include all possible Veppanu interactions. Always tell your health care provider and pharmacist about all prescription medicines, over-the-counter products, vitamins, herbs, and supplements you use.
Understanding Veppanu Interactions
Veppanu is taken by mouth once daily with food. The body breaks down Veppanu partly through enzymes in the liver and gut. Certain medicines can affect how quickly Veppanu is broken down, which may increase side effects or reduce how well the medicine works.
Veppanu can also affect how the body processes some other medicines. When combined with certain drugs that affect the heart’s electrical activity, Veppanu may also increase the risk of heart rhythm problems.
Next, we’ll cover five types of Veppanu interactions in more detail.
1. Medicines that affect heart rhythm (prolong QT interval)
Veppanu can cause QT prolongation, which is a specific change in the electrical activity of the heart, as seen on an EKG. Taking Veppanu with other medicines that also prolong the QT interval may increase the risk of serious heart rhythm problems.
Examples of medicines that may prolong the QT interval include:
- Amiodarone
- Citalopram
- Haloperidol
- Ondansetron
- Quetiapine
- Sotalol
- Some antibiotics, such as azithromycin and ciprofloxacin
Combining these medicines with Veppanu may increase the risk of serious or life-threatening arrhythmias.
Health care providers generally try to avoid these combinations when possible. If both medicines must be used together, you may need more frequent EKGs and blood tests to check potassium and magnesium levels. If you have heart rhythm changes, your health care provider may temporarily pause Veppanu, lower your dose, or stop treatment.
2. Certain antibiotics and antifungals
Some antibiotics and antifungal medicines can interact with Veppanu. This interaction may raise the risk of Veppanu side effects such as nausea, tiredness, and heart rhythm problems.
Examples include:
- Clarithromycin
- Itraconazole
- Ketoconazole
These medicines block (inhibit) an enzyme in the body called cytochrome P450 (CYP) 3A4, which helps break down Veppanu. When this enzyme is blocked, Veppanu can build up in the body and increase the risk of side effects.
Health care providers usually avoid combining these medicines with Veppanu. If the combination cannot be avoided, your provider may lower the Veppanu dose from 200 mg once daily to 100 mg once daily. They may adjust the dose again after the other medicine is stopped and out of your system. If you already take Veppanu 100 mg once daily, these combinations are generally avoided.
3. Some seizure medicines
Some seizure medicines can lower the amount of Veppanu in the body, making it less effective.
Examples include:
These medicines can make the body break down Veppanu faster than usual by speeding up (inducing) the CYP3A4 enzyme. This may lower the amount of Veppanu in your body, reducing how well it works against breast cancer.
Health care providers usually avoid combining these medicines with Veppanu. If the combination cannot be avoided, your provider may increase the Veppanu dose. They may adjust the dose again after you stop the other medicine and it clears from your system. Do not make any changes to your dose unless your health care provider tells you to do so.
4. Colchicine
Colchicine is a medicine commonly used for gout. Taking colchicine with Veppanu may increase the amount of colchicine in the body and raise the risk of serious side effects.
Veppanu blocks a transport protein called P-glycoprotein (P-gp), which helps move certain medicines through the body. Because colchicine depends on this pathway, Veppanu may increase colchicine levels.
Higher colchicine levels may increase the risk of side effects such as severe diarrhea, nausea, vomiting, and muscle pain or weakness.
Health care providers may avoid this combination when possible. If both medicines must be used together, your provider may lower the colchicine dose and monitor you more closely for side effects. Tell your health care provider right away if you develop severe stomach symptoms, unusual muscle pain, or weakness while taking these medicines together.
5. Dabigatran
Dabigatran is a blood thinner used to help prevent blood clots and stroke. Like colchicine, dabigatran is transported in the body by the P-gp protein. Since Veppanu blocks P-gp, taking dabigatran with Veppanu may increase the amount of dabigatran in the body and raise the risk of bleeding.
Health care providers may avoid prescribing this combination, especially if there is already a high risk of bleeding. If both medicines must be used, your provider may monitor you more closely for signs of bleeding or other side effects. Tell your health care provider right away if you notice unusual bruising, blood in your urine or stool, or bleeding that does not stop.
Veppanu and Alcohol
There are no known direct interactions between Veppanu and alcohol. However, alcohol may worsen certain side effects such as nausea, fatigue, dizziness, or liver problems.
If you choose to drink alcohol, ask your health care provider if or how much may be OK for you.
Food and Supplement Interactions
Certain foods and supplements may interact with Veppanu.
Examples include:
- St. John’s wort may lower Veppanu levels, making the medicine less effective.
- Grapefruit or grapefruit juice may increase Veppanu levels, raising the risk of side effects.
Avoid St. John’s wort, grapefruit, and grapefruit juice while you are taking Veppanu.
Other supplements may also cause interactions. Tell your health care team about all vitamins, herbs, and dietary supplements you use.
How to Avoid Veppanu Interactions
The following tips can help lessen your risk of drug interactions with Veppanu:
- Take Veppanu exactly as prescribed.
- Go to the recommended EKG and blood test appointments.
- Bring an up-to-date medicine list to your medical appointments and share it with your health care team.
- Tell your health care provider and pharmacist about all medicines, vitamins, herbs, and supplements you use.
- Properly dispose of unused or expired medicines to help prevent accidental use or interactions.
Your health care provider can let you know whether Veppanu is safe for you with your current medicines and supplements.
