Idvynso is used to treat HIV. While it can be an effective treatment for certain people, Idvynso can interact with other medicines and substances.
An interaction occurs when one medicine changes how another medicine works or affects your body. Avoiding certain interactions can help your treatment work effectively and reduce the risk of problems.
This article does not include all possible Idvynso interactions. Always tell your health care provider and pharmacist about all prescription drugs, over-the-counter medicines, and any vitamins, herbs, or other supplements you use.
Understanding Idvynso Interactions
Idvynso is a once-daily tablet that contains two medicines: doravirine and islatravir.
After you take a dose of Idvynso, your body breaks down part of the medicine (doravirine) using enzymes in the liver and gut. Some medicines can speed up or slow down this process. This can change the amount of Idvynso in your body. If levels are too low, the medicine may not work as well. If levels are too high, the risk of side effects may increase.
In addition, one part of Idvynso (islatravir) must be changed into its active form inside your cells before it can work. Some medicines can interfere with this step, which may reduce how well Idvynso treats HIV.
While not a complete list, below are some details about six Idvynso interactions to be aware of, along with how they are typically managed.
1. Other HIV medications
Some HIV medicines should not be taken with Idvynso.
Examples include:
- Efavirenz
- Emtricitabine
- Etravirine
- Lamivudine
Taking these medicines with Idvynso may reduce how well Idvynso works, so these combinations are not recommended.
Idvynso is a complete treatment for HIV. This means it is taken by itself and does not need to be combined with other HIV medicines. If your health care provider prescribes Idvynso, they will let you know when to stop your current treatment plan and how to switch to Idvynso safely.
2. Certain seizure medicines
Some seizure medicines can make Idvynso less effective by causing your body to break it down too quickly.
Examples include carbamazepine and fosphenytoin.
These medicines can increase the speed at which your body processes Idvynso. This may lower the amount of medicine in your body and make it harder to keep HIV under control.
Because of this risk, these medicines should not be taken with Idvynso. Your health care provider will likely recommend a different option. You may need to stop these medicines for at least four weeks before starting Idvynso; your health care provider will give you specific instructions.
3. Other medicines that speed up drug breakdown
Some other types of medicines can make Idvynso less effective.
Examples include:
- Armodafinil
- Apalutamide
- Enzalutamide
These medicines can cause your body to break down Idvynso faster by speeding up an enzyme called CYP3A4. This can reduce how well the medicine works.
These medicines should not be taken with Idvynso or for at least four weeks before starting Idvynso. Your health care provider will usually recommend a different option. Do not stop or change any medicines unless your health care provider recommends it.
4. Certain chemotherapy medicines
Some chemotherapy medicines for cancer can make Idvynso less effective. These medicines may interfere with how the islatravir part of Idvynso becomes active in your body.
Examples include:
- Cladribine
- Clofarabine
- Cytarabine
- Fludarabine
- Gemcitabine
Another type of chemotherapy medicine called pentostatin can increase the amount of islatravir in your body. It does this by slowing down how your body breaks it down. When islatravir builds up to higher levels, it may increase the risk of side effects.
These medicines are usually not taken together. Your health care provider may recommend a different treatment instead.
5. Rifabutin
Rifabutin is a medicine used to prevent and treat Mycobacterium avium complex (MAC) infections, which are bacterial infections that can affect people with HIV.
Taking rifabutin with Idvynso may make Idvynso less effective. This is because rifabutin can speed up the breakdown of the doravirine part of Idvynso, which may lower its levels in your body.
Unlike some other interactions, these medicines may sometimes still be used together. If you need to take rifabutin, your health care provider may adjust your treatment.
In this case, you may be instructed to take Idvynso once daily as usual, then take a separate dose of doravirine about 12 hours later. This helps maintain enough medicine in your body to keep HIV under control.
Always follow your health care provider’s instructions carefully if you are taking both of these medicines.
6. Certain medicines for infections
Certain antibiotics, antifungals, and antivirals can increase the amount of Idvynso in your body.
Examples include:
These medicines slow down how your body breaks down Idvynso. This can cause the medicine to build up, increasing the risk of side effects.
If these medicines need to be taken together, your health care provider may monitor you more closely for side effects or adjust your treatment.
Other Interactions With Idvynso
Alcohol
There are no known interactions between Idvynso and alcohol.
However, heavy alcohol use can weaken your immune system and make it harder for your body to fight infections. It may also make it harder to stay on track with your treatment plan.
Talk to your health care provider about whether alcohol use is safe for you.
Supplements
Some supplements may interact with Idvynso. The drugmaker of Idvynso did not list any specific supplement interactions in the medicine’s labeling. One possible interaction is an herbal supplement called St. John’s wort, which some people use for mood support. It may reduce how well Idvynso works.
This supplement could cause your body to break down Idvynso more quickly, lowering its effectiveness.
Other supplements may also cause interactions or have unknown risks. Tell your health care team about all supplements you take.
Food
Idvynso can be taken with or without food.
The drugmaker of Idvynso does not specifically list grapefruit or grapefruit juice as an interaction in the prescribing information. Still, your health care provider may recommend limiting or avoiding grapefruit and grapefruit juice. The combination may increase the risk of Idvynso side effects.
Grapefruit can slow down how your body breaks down Idvynso. When this happens, higher levels of the medicine can build up in your body, which may increase the chance of side effects.
Vaccines
There are no known direct interactions between Idvynso and vaccines.
But HIV can affect how your immune system responds to vaccines. Talk to your health care provider about which vaccines are right for you while taking Idvynso.
How to Avoid Idvynso Interactions
Because Idvynso is used to keep HIV under control, taking Idvynso exactly as prescribed and avoiding interactions is important to maintain a low viral load and prevent resistance.
You can lower your risk of interactions while taking Idvynso by following a few key steps. To reduce your risk:
- Keep an updated list of all medicines, vitamins, herbs, or supplements you use.
- Share this list with your health care provider and pharmacist before you start any new medicine.
- Check with your health care provider or pharmacist before you use any new over-the-counter products.
- Dispose of unused or expired medicines properly to prevent accidental use.
Your health care provider can help determine whether Idvynso is safe for you and make sure your treatment plan continues to work as intended.
