Paxlovid Drug Interactions: Which Medicines to Stop, Reduce, or Keep Taking

If you've been prescribed Paxlovid (nirmatrelvir/ritonavir) for COVID-19, your medication list matters just as much as the prescription itself.

The ritonavir in Paxlovid is a strong CYP3A inhibitor. It can raise blood levels of medications that are metabolized through CYP3A, sometimes enough to cause serious or even life-threatening side effects. Other medicines can do the opposite by lowering Paxlovid levels and potentially reducing its effectiveness.

That does not mean you cannot take Paxlovid if you use other medications. Many interactions can be managed by temporarily stopping a medication, adjusting its dose, changing the timing, or monitoring you more closely.

The important part is knowing which category your medication falls into. Do not stop an important prescription on your own, especially blood thinners, seizure medications, heart medications, or immunosuppressants.

TL;DR: Key Takeaways

• Ritonavir can substantially change the levels of many medications, so your complete medication list should be reviewed before starting Paxlovid.
• Simvastatin and lovastatin are contraindicated with Paxlovid and must be stopped before, during, and for several days after treatment.
• Atorvastatin may be temporarily stopped during Paxlovid treatment. The US label does not require it to be held before or after the course.
• Some medications, including alfuzosin, ranolazine, certain antiarrhythmics, and sildenafil when used for pulmonary arterial hypertension, should not be combined with Paxlovid.
• Blood thinners such as apixaban and rivaroxaban require medication-specific management because Paxlovid can increase bleeding risk.
• Tacrolimus and other immunosuppressants can have major interactions and require transplant-team or specialist management.
• Combined hormonal contraceptives containing ethinyl estradiol may require an additional non-hormonal contraceptive method during Paxlovid treatment and until one menstrual cycle afterward.
• Many common medications can be continued, but there is no reliable "safe medication list" that replaces an individual interaction check.
• The University of Liverpool COVID-19 Drug Interactions Checker is a useful resource for checking specific medications, but your prescriber or pharmacist should make the final medication-management decision.

Considering Paxlovid and want a clinician to review your medications for interactions? Book a $39 online urgent care visit with August AI. A US-licensed clinician can review your medication list and prescribe treatment when clinically appropriate. The visit does not guarantee a prescription, and medication costs are separate. For transplant patients, complex medication regimens, or medications requiring drug-level monitoring, your primary care clinician or specialist may be better positioned to manage the interaction.

Medications to STOP or avoid with Paxlovid

Not every medication in this section should simply be stopped at home. Some are contraindicated with Paxlovid, while others may be temporarily held only under clinician direction.

Statins

Statins are one of the most commonly discussed Paxlovid interactions, but they do not all need to be managed in the same way.

Simvastatin (Zocor) and lovastatin (Mevacor) have a major interaction with ritonavir. The FDA prescribing information says they should be discontinued at least 12 hours before starting Paxlovid, throughout the 5-day treatment course, and for 5 days after finishing Paxlovid. The concern is a large increase in statin exposure and the resulting risk of muscle injury, including rhabdomyolysis.

Atorvastatin (Lipitor) is different. The US Paxlovid label says to consider temporarily discontinuing atorvastatin during treatment. It does not need to be withheld before starting Paxlovid or after completing the course.

Rosuvastatin (Crestor) may require dose limitations depending on the interaction guidance being followed, while pravastatin is generally less affected by CYP3A inhibition.

The exact plan depends on the statin, dose, and your other medications. Do not assume that every statin needs to be stopped for the same number of days.

For context on statin cost considerations that may apply to your management, see our guide on atorvastatin cost without insurance: what you'll really pay in 2026.

Medications that are restricted with Paxlovid

The FDA lists several medications that should not be coadministered with Paxlovid because the interaction can be dangerous. Examples include:

• Alfuzosin: risk of severely low blood pressure
• Ranolazine: risk of serious cardiac effects, including QT prolongation
• Amiodarone, dronedarone, flecainide, propafenone, and quinidine: serious antiarrhythmic interactions
• Sildenafil (Revatio) when used for pulmonary arterial hypertension: potentially dangerous increase in drug exposure
• Triazolam and oral midazolam: excessive sedation and respiratory depression
• Ergotamine and dihydroergotamine: risk of severe vasospasm
• Lurasidone and pimozide: potentially serious increases in drug levels
• Rifampin and rifapentine: can substantially reduce Paxlovid concentrations
• St. John's wort: can reduce Paxlovid concentrations
• Carbamazepine, phenytoin, phenobarbital, and primidone: strong enzyme induction can reduce Paxlovid effectiveness

This is not a complete list. The current FDA prescribing information contains additional contraindicated medications and emphasizes that its interaction tables are not exhaustive.

If you take one of these medications, tell the prescriber before starting Paxlovid. In some cases, another COVID-19 treatment may be considered rather than trying to manage the interaction.

Colchicine

Colchicine deserves special attention because ritonavir can substantially increase colchicine exposure.

The combination is contraindicated in people with renal or hepatic impairment, and dose adjustment or avoidance may be necessary in other situations.

Do not simply stop colchicine without medical advice. Tell the prescriber that you take it and provide your dose and kidney and liver history.

Medications that may need a dose change or closer monitoring

Some interactions do not automatically rule out Paxlovid. Instead, the medication may need a temporary dose reduction, interruption, or additional monitoring.

• Blood thinners
• Blood thinners are a good example of why "continue" or "stop" lists can be misleading.
• Apixaban (Eliquis) can reach higher concentrations when combined with Paxlovid, increasing bleeding risk. The appropriate adjustment depends on the apixaban dose and the reason you take it. Some dosing situations call for a reduction, while others may require avoiding the combination.
• Rivaroxaban (Xarelto) also has a significant interaction with Paxlovid and may require an alternative anticoagulation strategy rather than simply continuing the usual dose.
• Warfarin can generally be managed with continued treatment and closer INR monitoring, but the monitoring plan should come from the clinician managing your anticoagulation.

Do not stop a blood thinner on your own. The risk of a clot from abruptly interrupting anticoagulation can be serious.

Immunosuppressants

This is one of the most important interaction categories.

Tacrolimus, cyclosporine, sirolimus, and everolimus can interact strongly with ritonavir. Tacrolimus concentrations, in particular, can rise rapidly to toxic levels. The interaction can require substantial dose changes, temporary interruption, and repeated drug-level monitoring.

If you have had an organ transplant, contact your transplant team before taking Paxlovid. Do not change your immunosuppressant dose based on an online medication list.

Heart and blood pressure medications

Some cardiovascular medications interact with Paxlovid while others do not.

Examples include:

• Amlodipine and some other calcium channel blockers: may require dose adjustment or monitoring
• Digoxin: may require monitoring and sometimes dose adjustment
• Beta-blockers: many can be continued, depending on the specific medication
• ACE inhibitors and ARBs: many do not have a clinically significant interaction

The key is the individual medication, not simply the drug category. The FDA specifically lists calcium channel blockers and other cardiovascular medications among drugs that may require management when Paxlovid is prescribed.

Mental health medications

Many antidepressants can be used with Paxlovid, but some psychiatric medications have important interactions.

For example, bupropion can interact with ritonavir, although the effect may not require stopping treatment. Some antipsychotics and sedatives have much more significant interactions.

This is why "antidepressants are safe" is too broad. Give the prescriber the exact medication name and dose.

For guidance on tracking your complete medication list and coordinating care, see our guide on how to view your medical records online for free.

Medications that can often be continued

Many commonly used medications do not require a Paxlovid dose change.

Examples can include:

• Acetaminophen (Tylenol)
• Ibuprofen (Advil)
• Naproxen (Aleve)
• Many antihistamines
• Many antacids
• Metformin
• Insulin
• Levothyroxine
• Many ACE inhibitors and ARBs
• Many beta-blockers
• Omeprazole and other proton pump inhibitors
• Prenatal vitamins

But "usually compatible" does not mean "automatically safe." Some medications within the same category interact differently.

For example, saying "most antibiotics are safe" is not enough because some antibiotics, including clarithromycin and erythromycin, can themselves interact with Paxlovid.

If you take several prescriptions, an interaction checker or pharmacist review is more useful than trying to compare your medications with a general list online.

What about birth control?

Combined hormonal contraceptives containing ethinyl estradiol deserve a specific note.

Ritonavir can reduce ethinyl estradiol exposure. The Paxlovid labeling recommends using an effective alternative or additional barrier method during the 5-day Paxlovid course and until one complete menstrual cycle after stopping treatment.

That does not mean every form of hormonal contraception needs to be stopped. The interaction depends on the contraceptive and its ingredients.

If you use birth control, tell your clinician exactly which pill, patch, ring, implant, or other method you use.

What about steroids?

Some corticosteroids can interact with ritonavir because their concentrations may increase.

Fluticasone, including inhaled or intranasal forms, is one example. The risk of clinically important steroid effects is generally lower with a short 5-day Paxlovid course than with long-term ritonavir treatment, but the interaction still deserves consideration. Alternative corticosteroids may sometimes be preferred.

Do not abruptly stop a steroid that you have been prescribed regularly. Ask your clinician or pharmacist how it should be managed.

What about vitamins, supplements, alcohol, and CBD?

Prescription medications are not the only things worth mentioning.

St. John's wort

St. John's wort should not be combined with Paxlovid. It can induce enzymes that lower Paxlovid concentrations and potentially reduce its effectiveness.

Other supplements

Evidence varies widely for herbal products and supplements. Some may affect drug metabolism or bleeding risk, and supplement labels do not always make interactions obvious.

Tell your clinician about:

• Herbal supplements
• Multivitamins
• CBD products
• Other cannabis products
• Workout or performance supplements
• Over-the-counter medications

Alcohol

Alcohol is not generally listed as a major direct contraindication to Paxlovid, but drinking while you are sick can worsen dehydration, nausea, dizziness, or other symptoms.

If you are taking other medications that interact with alcohol, that can change the situation. Ask your pharmacist or clinician if you are unsure.

Use the Liverpool COVID-19 Drug Interactions Checker

Because Paxlovid has so many potential interactions, a general list cannot cover every medication.

The University of Liverpool's COVID-19 Drug Interactions Checker is a useful free resource for checking specific drug combinations. It provides interaction information for nirmatrelvir/ritonavir and many other COVID-19 treatments.

You can use it to:

1. Select nirmatrelvir/ritonavir.
2. Search for your medication.
3. Review the interaction result.
4. Take the result to your clinician or pharmacist if an interaction is identified.

The checker is useful for research and medication review, but it should not replace individualized medical advice. Some interactions depend on your dose, kidney function, liver function, indication for the medication, and other drugs you take.

When should you contact a physician?

Contact your prescriber or pharmacist if:

• You take several prescription medications.
• You take a blood thinner.
• You have had an organ transplant.
• You take tacrolimus or another immunosuppressant.
• You take an antiarrhythmic medication.
• You take a seizure medication.
• You use hormonal contraception.
• You take a medication with a narrow therapeutic range.
• You are unsure whether a medication should be continued.
• You already started Paxlovid and then discovered a possible interaction.

Do not independently stop critical medications simply because you see them on an interaction list. The right response depends on what the medication is treating and what the alternative would be.

Seek emergency care for severe symptoms

Get urgent medical attention for symptoms such as:

• Severe difficulty breathing
• Chest pain or pressure
• Fainting or severe dizziness
• Severe or rapidly worsening weakness
• Severe muscle pain or weakness after taking an interacting medication
• Significant or uncontrolled bleeding
• Severe confusion or inability to stay awake
• Signs of a serious allergic reaction

For a look at what specific side effects to watch during Paxlovid treatment, see our guide on Paxlovid side effects: the taste, the timeline, and the risk that actually matters.

Conclusion

Paxlovid drug interactions are an important part of deciding whether and how to use the medication. Ritonavir can increase the concentration of some medicines to dangerous levels, while other drugs can lower Paxlovid concentrations and make treatment less effective.

The practical approach is not to memorize a giant list of drugs to stop.

Instead:

• STOP or avoid medications that are contraindicated with Paxlovid, but only after the prescriber has reviewed the situation.
• TEMPORARILY HOLD or ADJUST medications such as certain statins when appropriate.
• MONITOR medications such as some blood thinners and cardiovascular drugs when the combination is appropriate.
• GET SPECIALIST HELP for tacrolimus and other immunosuppressants.
• CONTINUE medications that have been confirmed to be compatible rather than stopping everything unnecessarily.
• CHECK every prescription, OTC medication, and supplement before starting treatment.

Bring your complete medication list to the prescriber or pharmacist. If you take several medications, do not rely on a general internet list to decide what to stop.

For a look at what to expect during and after treatment, see our guides on Paxlovid side effects, Paxlovid rebound, and Paxlovid cost in 2026.