Why Biktarvy Drug Interactions Matter

Biktarvy is generally well-tolerated with fewer drug interactions than many older HIV regimens. But it still interacts with some common medications and supplements — and a few of those interactions can be dangerous.

Knowing what to watch for can help you stay safe and keep your HIV treatment effective. This guide covers the major and moderate interactions, what supplements to be careful with, and exactly what to tell your doctor.

How Drug Interactions Work With Biktarvy

Drug interactions with Biktarvy generally fall into two categories:

• Drugs that reduce Biktarvy's effectiveness — some medications speed up how your body breaks down bictegravir, which can lower Biktarvy's levels in your blood and allow HIV to replicate
• Drugs whose levels increase when taken with Biktarvy — Biktarvy can raise the levels of certain other medications in your body, increasing the risk of their side effects

There are also interactions where minerals (like calcium, iron, aluminum, and magnesium) physically bind to Biktarvy in your gut and prevent it from being absorbed properly.

Medications That Interact With Biktarvy

Contraindicated — Do NOT Take Together

These combinations are considered dangerous and should never be used together:

• Dofetilide (Tikosyn) — a heart rhythm medication. Taking it with Biktarvy can increase dofetilide levels and cause serious, potentially life-threatening heart arrhythmias.
• Rifampin (Rifadin) — an antibiotic used for tuberculosis and some other infections. Rifampin significantly reduces bictegravir levels in your blood, which can make Biktarvy ineffective against HIV.

Major Interactions — Use With Caution or Avoid

These medications can significantly reduce Biktarvy's effectiveness by lowering bictegravir levels:

• Carbamazepine (Tegretol) — anticonvulsant/mood stabilizer
• Oxcarbazepine (Trileptal) — anticonvulsant
• Phenobarbital — anticonvulsant/sedative
• Phenytoin (Dilantin) — anticonvulsant
• St. John's wort — herbal supplement used for depression
• Rifabutin (Mycobutin) — antibiotic sometimes used in TB or MAC treatment
• Rifapentine (Priftin) — antibiotic used for TB

If you need any of these medications, your doctor will need to find an alternative or adjust your treatment plan. Do not start any of these medications without telling your HIV provider first.

Moderate Interactions — Timing Matters

These interactions can usually be managed by separating doses or taking medications together with food:

• Antacids containing aluminum, magnesium, or calcium (such as Tums, Maalox, Mylanta) — these minerals bind to Biktarvy and reduce absorption. Take Biktarvy at least 2 hours before or 2 hours after antacids.
• Sucralfate (Carafate) — a stomach ulcer medication that contains aluminum. Separate administration from Biktarvy.
• Metformin (Glucophage) — a diabetes medication. Bictegravir may increase Metformin levels in your blood. Your doctor should monitor you for Metformin side effects (like nausea, diarrhea, or lactic acidosis) and may need to adjust your Metformin dose.

Supplements and OTC Medications to Watch

Some common over-the-counter products can also interact with Biktarvy:

• Iron supplements — iron binds to Biktarvy and reduces absorption. Take iron with food at the same time as Biktarvy, or separate by at least 2 hours.
• Calcium supplements — same as iron. Take with food together with Biktarvy, or separate by 2 hours.
• Multivitamins containing minerals — many multivitamins contain iron, calcium, magnesium, or aluminum. Follow the same timing rules as above.
• St. John's wort — this popular herbal supplement for depression significantly reduces bictegravir levels. Do not take St. John's wort with Biktarvy.

In general, supplements like vitamin D, vitamin C, B vitamins, and omega-3 fatty acids do not interact with Biktarvy. But always tell your doctor about everything you take.

Food and Drink Interactions

The good news: Biktarvy can be taken with or without food, and there are no significant food interactions. You don't need to avoid any specific foods or beverages.

The only food-related consideration is when taking mineral supplements — if you take iron or calcium with food at the same time as Biktarvy, the food helps reduce the binding interaction.

What to Tell Your Doctor

Before starting Biktarvy, and at every visit, make sure your doctor knows about:

• All prescription medications — especially heart medications, seizure medications, antibiotics (particularly rifamycins), and diabetes medications
• All over-the-counter medications — including antacids, pain relievers, and allergy medications
• All supplements and vitamins — including herbal products like St. John's wort, and any mineral supplements
• Any new medications — if another doctor prescribes something new, tell them you take Biktarvy and let your HIV provider know
• Hepatitis B status — if you have hepatitis B, this affects how Biktarvy should be managed

It's a good idea to keep a current list of all your medications and supplements in your phone or wallet. Show this list to every doctor, pharmacist, or urgent care provider you see.

Your pharmacist is also a great resource — they can check for interactions whenever you fill a new prescription. Don't be afraid to ask.

Final Thoughts

Biktarvy has fewer drug interactions than many older HIV regimens, but there are still important ones to know about. The contraindicated combinations (Dofetilide and Rifampin) are non-negotiable — those drugs cannot be used with Biktarvy. For mineral supplements and antacids, simple dose timing usually solves the problem. The most important thing you can do is keep your providers informed about everything you take. For more about Biktarvy, see our guides on uses and dosage and side effects.