Paxlovid interactions to avoid

In this article:

• Paxlovid-drug interactions
• Paxlovid food interactions
• Other Paxlovid interactions
• How to minimize interactions
• When to see your doctor

In this article

• Paxlovid-drug interactions
• Paxlovid food interactions
• Other Paxlovid interactions
• How to minimize interactions
• When to see your doctor

Paxlovid is an oral antiviral medication developed to treat COVID-19. The drug consists of two active ingredients, nirmatrelvir and ritonavir, which work as protease inhibitors to reduce the spread and number of viruses in the body. Paxlovid can be a useful drug that can decrease the risk of hospitalization or death in high-risk individuals with COVID-19. However, it doesn’t come without the risk of drug interactions, which could decrease its effectiveness or cause harmful side effects. 

Paxlovid–drug interactions

Paxlovid, developed by Pfizer and granted initial Emergency Use Authorization and subsequent approval by the Food and Drug Administration (FDA) for COVID-19, is associated with several drug-drug interactions. Let’s explore the various drugs, including both prescription and over-the-counter (OTC) medications, that can interact with Paxlovid. 

Statins

Paxlovid can interact with HMG-CoA reductase inhibitors, also known as statins, which are used to manage high cholesterol levels. Ritonavir in Paxlovid blocks the enzyme that processes statins, which can lead to increased statin blood levels. Increased statin levels may cause increased statin side effects like muscle pain, weakness, and fatigue. Examples of statins that can interact with Paxlovid include:

• Zocor (simvastatin)
• Lipitor (atorvastatin)
• Mevacor (lovastatin)
• Crestor (rosuvastatin)

Calcium channel blockers

Another interaction involves calcium channel blockers, which treat high blood pressure (hypertension) and chest pain. Paxlovid can increase the concentrations of these drugs, potentially leading to side effects like dangerously low blood pressure, dizziness, and fatigue. Calcium channel blockers often do not need to be discontinued while taking Paxlovid. However, a decrease in the dosage of the calcium channel blocker is usually recommended to avoid potential side effects. Some common calcium channel blockers include:

• Norvasc (amlodipine)
• Procardia (nifedipine)
• Cardizem (diltiazem)
• Calan (verapamil)
• Plendil (felodipine)
• Cardene (nicardipine)

Anticoagulants and antiplatelet agents

Paxlovid may also interact with blood thinners, like anticoagulants and antiplatelet agents, which are used to prevent blood clots. Ritonavir can affect the metabolism of these drugs, potentially increasing their blood levels and the risk of bleeding problems. Examples of anticoagulant medications include:

• Coumadin (warfarin)
• Xarelto (rivaroxaban)
• Eliquis (apixaban)
• Pradaxa (dabigatran)

Examples of antiplatelet agents include:

• Plavix (clopidogrel)
• Brilinta (ticagrelor)

Antiarrhythmic drugs

Paxlovid can interact with certain antiarrhythmic drugs used to treat irregular heartbeats. The interaction may cause an increased risk of life-threatening heart rhythm problems. In general, using antiarrhythmic drugs with Paxlovid is contraindicated, meaning they should not be taken together at all. Examples of these antiarrhythmics include:

• Cordarone (amiodarone)
• Quinidex (quinidine)
• Lanoxin (digoxin)
• Tambocor (flecainide)
• Rythmol (propafenone)
• Multaq (dronedarone)

Cardiovascular agents

Some heart medications should not be taken with Paxlovid because the interaction can cause serious side effects. Combining Paxlovid with Inspra (eplerenone) should be avoided because the interaction can cause high levels of eplerenone and an increased risk of high potassium levels. Combining Paxlovid with Corlanor (ivabradine) can increase levels of ivabradine and lead to a slow heart rate or other heart problems. 

Psychiatric medications

Certain mental health medications, such as antipsychotics and benzodiazepines, may interact with Paxlovid. Taking a benzodiazepine with Paxlovid may lead to increased blood levels of the benzodiazepine, which can lead to sedation and respiratory depression, especially with high doses. Benzodiazepines include:

• Valium (diazepam)
• Versed (midazolam)
• Klonopin (clonazepam)
• Halcion (triazolam)

Certain antipsychotics, such as lurasidone and pimozide, should be avoided in combination with Paxlovid due to the risk of potentially dangerous heart rhythm problems. In some cases, the dosage of the antipsychotic drug may need to be reduced while taking Paxlovid. Antipsychotic medications include:

• Clozaril (clozapine)
• Orap (pimozide)
• Latuda (lurasidone)
• Seroquel (quetiapine)

In addition, Paxlovid may affect the levels of certain antidepressants. It can decrease the levels of bupropion and increase the levels of trazodone, which may require changes in dosages. 

Erectile dysfunction (ED) medications

Paxlovid can interact with medications used to treat ED. The co-administration of Paxlovid may lead to elevated blood levels of these ED drugs, which can increase the risk of adverse effects like low blood pressure, a prolonged and painful erection (priapism), and vision changes. Some common ED medications include:

• Viagra (sildenafil)
• Cialis (tadalafil)
• Levitra (vardenafil)
• Stendra (avanafil)

Migraine medications

A drug interaction is also possible with medications prescribed to treat migraines. Paxlovid could increase blood levels of these medications, potentially leading to increased side effects. For example, taking ergot derivatives like dihydroergotamine and ergotamine with Paxlovid could lead to ergot toxicity with symptoms like nausea, dizziness, and increased blood pressure. Examples of migraine medications include:

• Migranal (dihydroergotamine)
• Ergomar (ergotamine)
• Relpax (eletriptan)
• Ubrelvy (ubrogepant)

Opioids and opioid antagonists

There is a potential interaction between Paxlovid and certain opioid pain medications. Taking Paxlovid can increase the levels of opioids, which may lead to serious side effects such as severe respiratory depression. In addition, taking Paxlovid with the opioid antagonist naloxegol is not recommended due to the risk of opioid withdrawal symptoms. Some examples of opioids include:

• Duragesic (fentanyl)
• Zohydro ER (hydrocodone)
• Oxycontin (oxycodone)
• Demerol (meperidine)

Hormonal contraceptives

Birth control pills like those containing ethinyl estradiol may interact with Paxlovid. This interaction can alter the contraceptive‘s effectiveness, leading to an increased risk of unintended pregnancy. It’s recommended to use other forms of contraception, such as condoms, during treatment with Paxlovid. In addition, non-oral contraceptives should be continued until one menstrual cycle after stopping Paxlovid. Common hormonal contraceptives include:

• Yaz (drospirenone and ethinyl estradiol)
• Ortho Tri-Cyclen (norgestimate and ethinyl estradiol)
• Femynor (norgestimate and ethinyl estradiol)

Immunosuppressants

Paxlovid may interact with immunosuppressants commonly used to prevent organ rejection after transplantation. Elevated blood levels of these drugs could increase the risks of adverse events, such as kidney damage. It’s generally recommended to avoid combining these immunosuppressants with Paxlovid, although certain immunosuppressants may be used with Paxlovid if the dosage is adjusted and side effects are monitored. Examples of these immunosuppressants include:

• Prograf (tacrolimus)
• Rapamune (sirolimus)
• Sandimmune (cyclosporine)
• Zortress (everolimus)

Anticonvulsants

Certain anticonvulsants can interact with Paxlovid, decreasing the levels of Paxlovid in the body. This interaction may lead to decreased effectiveness and potential viral resistance to Paxlovid. It’s recommended to avoid taking anticonvulsants with Paxlovid. The anticonvulsants in question include:

 

• Luminal (phenobarbital)
• Dilantin (phenytoin)
• Tegretol (carbamazepine)
• Mysoline (primidone)

This is a general guide and may not cover all the interactions of Paxlovid. Those who take medications other than Paxlovid should consult their prescribing healthcare provider for possible dose adjustments or alternative options when prescribed Paxlovid. 

Paxlovid food interactions

According to the FDA label, Paxlovid can be taken with or without food. Eating a high-fat meal did not significantly affect the blood levels of nirmatrelvir. However, studies have shown that eating a meal may decrease the levels of ritonavir by around 20%, which could lead to decreased effectiveness of the drug. 

Paxlovid and grapefruit

Although this interaction isn’t mentioned on the drug label, grapefruit may prevent your body from breaking down Paxlovid properly, increasing the risk of side effects. It’s best to avoid grapefruit and grapefruit juice while taking Paxlovid.

Paxlovid and alcohol

There’s no known direct interaction between Paxlovid and alcohol, but alcohol can weaken your immune system and worsen side effects. Limiting or avoiding alcohol is recommended.

Paxlovid and caffeine

Caffeine may increase side effects for some people on Paxlovid. Moderate intake, like a cup of coffee, is generally safe.

Dietary recommendations

For people with or at risk of infection with the coronavirus, it may be beneficial to consider dietary recommendations. Maintaining a balanced diet rich in fruits, vegetables, whole grains, lean proteins, and healthy fats is recommended to support the immune system. Healthcare providers may also recommend staying well-hydrated by drinking water and avoiding excessive caffeine or sugar to maintain optimal health. 

Other Paxlovid interactions

Paxlovid may also interact with herbal or dietary supplements and other OTC medicines. Paxlovid may interact with other substances, including:

• • St. John’s wort: Taking this herbal supplement with Paxlovid may lead to reduced blood levels of Paxlovid. As a result, St. John’s wort may decrease the effectiveness of Paxlovid. 
  • Cannabis: While specific interactions between Paxlovid and cannabis are not well-established, ritonavir in Paxlovid may affect the metabolism of THC and CBD in cannabis. Mixing Paxlovid and cannabis use could lead to increased concentrations and more potent effects of THC and CBD. 

• Cough and cold medicines: These medicines should generally be safe to take with Paxlovid when taken as directed. However, some cough and cold medicines may contain dextromethorphan, a cough suppressant. Paxlovid may slightly increase the levels of dextromethorphan in the body and increase the risk of side effects. 

Consult your healthcare provider about any supplements or other substances you are taking before starting treatment with Paxlovid.

How to minimize Paxlovid interactions

The best way to reduce the risk of Paxlovid interactions is to be aware of potential interactions with other medications or supplements you may be taking. Keep an updated list at all times and relay all medications you take to your healthcare provider so they can determine whether there’s a risk of drug interactions.

In addition, pay attention to how you feel during treatment. If you notice any unusual side effects or changes in your health, contact your healthcare provider. They can help determine if these symptoms are related to drug interactions and make changes to your treatment plan as needed.

When to talk to a healthcare provider about Paxlovid interactions

You should talk to a healthcare provider about Paxlovid interactions during the initial visit when they prescribe the medication. You can also consult your local pharmacist if you have concerns about drug interactions. 

In general, you should talk to healthcare providers about Paxlovid interactions if you:

• Take any prescription or over-the-counter medications
• Use any dietary supplements or herbal products
• Have any medical conditions or a history of certain illnesses, including kidney or renal impairment, liver problems such as hepatitis, and human immunodeficiency virus 1 (HIV-1)
• Experience any unexpected side effects or changes in health

This article does not provide a complete list of Paxlovid interactions. Discuss your overall medical history, including medical conditions and other medications you take, with your healthcare provider before starting treatment.