Know What Interacts With Descovy Before You Start

If you're taking Descovy — or about to start — it's important to understand which other medications, supplements, and substances could interact with it. Drug interactions can make Descovy less effective or increase your risk of side effects.

This guide breaks down the major and moderate interactions you should know about, plus what to tell your doctor before starting Descovy.

How Drug Interactions Work With Descovy

Descovy contains two active ingredients: Emtricitabine (FTC) and Tenofovir Alafenamide (TAF). Drug interactions with Descovy mainly happen in two ways:

1. P-glycoprotein (P-gp) effects: TAF is transported into cells by a protein called P-glycoprotein. Drugs that block P-gp can cause TAF levels to rise (increasing side effect risk), while drugs that stimulate P-gp can cause TAF levels to drop (reducing effectiveness).
2. Kidney competition: Emtricitabine and tenofovir are cleared through the kidneys. Other drugs that compete for the same kidney pathways can increase concentrations of these medications, raising the risk of kidney-related side effects.

Understanding these mechanisms helps explain why certain medications are flagged as interactions.

Major Drug Interactions

The following interactions are considered serious and should be carefully managed or avoided:

Other HIV Medications Containing Emtricitabine or Tenofovir

Do not take Descovy with any other product containing Emtricitabine or Tenofovir. This includes:

• Truvada (Emtricitabine/Tenofovir Disoproxil Fumarate)
• Atripla (Efavirenz/Emtricitabine/Tenofovir DF)
• Complera (Emtricitabine/Rilpivirine/Tenofovir DF)
• Stribild (Elvitegravir/Cobicistat/Emtricitabine/Tenofovir DF)
• Genvoya (Elvitegravir/Cobicistat/Emtricitabine/TAF)
• Odefsey (Emtricitabine/Rilpivirine/TAF)
• Symtuza (Darunavir/Cobicistat/Emtricitabine/TAF)
• Biktarvy (Bictegravir/Emtricitabine/TAF)

Taking Descovy alongside these medications would double your dose of Emtricitabine and/or Tenofovir, significantly increasing side effect risk without added benefit.

Drugs That Affect Kidney Function

Medications that stress the kidneys or compete for the same elimination pathways can increase Emtricitabine and Tenofovir levels in your blood. These include:

• Acyclovir (Zovirax) and Valacyclovir (Valtrex) — antiviral medications
• Cidofovir — antiviral medication
• Ganciclovir and Valganciclovir (Valcyte) — antiviral medications
• Aminoglycoside antibiotics (Gentamicin, Tobramycin, Amikacin)
• High-dose NSAIDs (Ibuprofen, Naproxen) — occasional use at normal doses is generally fine, but chronic high-dose use should be avoided

If you need any of these medications, your doctor should monitor your kidney function more closely.

Moderate Drug Interactions

These interactions may reduce Descovy's effectiveness by lowering TAF levels in your body:

Anticonvulsants That Induce P-gp

Certain seizure medications speed up the breakdown of TAF, potentially making Descovy less effective:

• Carbamazepine (Tegretol)
• Oxcarbazepine (Trileptal)
• Phenobarbital
• Phenytoin (Dilantin)

If you take any of these, your doctor may need to consider alternative seizure medications or adjust your HIV treatment plan.

Rifamycin Antibiotics

These antibiotics, commonly used to treat tuberculosis, can significantly reduce TAF levels:

• Rifampin (Rifadin)
• Rifabutin (Mycobutin)
• Rifapentine (Priftin)

Co-administration with Rifampin in particular is a significant concern and generally should be avoided.

P-gp Inhibitors

On the flip side, drugs that inhibit P-glycoprotein can increase TAF levels. While this doesn't always cause problems, your doctor should be aware if you're taking strong P-gp inhibitors so they can monitor for increased side effects.

Supplements and Over-the-Counter Products to Watch

St. John's Wort

St. John's Wort (Hypericum perforatum) is a popular herbal supplement used for depression. It is a potent inducer of P-gp and can significantly reduce TAF levels, potentially making Descovy ineffective. Do not take St. John's Wort with Descovy.

NSAIDs

Over-the-counter pain relievers like Ibuprofen (Advil, Motrin) and Naproxen (Aleve) are generally safe for occasional use. However, chronic high-dose use can affect kidney function and may increase Tenofovir levels. For regular pain management, Acetaminophen (Tylenol) is a safer alternative while on Descovy.

Calcium, Iron, and Antacids

Unlike some HIV medications, Descovy does not have significant interactions with calcium supplements, iron supplements, or antacids. You can take these as needed without timing restrictions relative to your Descovy dose.

Food and Drink Interactions

Descovy has no known food interactions. You can take it with or without food, at any time of day. There are no restrictions on specific foods, alcohol (though excessive alcohol use can harm your liver and overall health), or beverages.

This is one of Descovy's practical advantages — no complicated meal timing or dietary restrictions to remember.

What to Tell Your Doctor

Before starting Descovy, give your healthcare provider a complete list of:

• All prescription medications you currently take, including other HIV medications
• Over-the-counter medications, including pain relievers and antacids
• Herbal supplements, especially St. John's Wort
• Vitamins and mineral supplements
• Any kidney problems or history of kidney disease
• Hepatitis B status — this affects both starting and stopping Descovy

If you start any new medication while taking Descovy, tell both your prescriber and your pharmacist so they can check for interactions.

Final Thoughts

Descovy has fewer drug interactions than many HIV medications, but the ones it does have are important. The biggest risks come from other Tenofovir-containing products, kidney-stressing medications, P-gp inducers like Rifampin and St. John's Wort, and certain anticonvulsants.

The simplest way to stay safe is to keep your doctor and pharmacist fully informed about everything you take. For more about Descovy, check out our guides on side effects and uses and dosage. Ready to fill your prescription? Find Descovy near you on Medfinder.