nirmatrelvir/ritonavir vs sildenafil
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Side-by-side comparison of nirmatrelvir/ritonavir and sildenafil. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
major Known Drug Interaction
Pulmonary hypertension agents (PDE5 inhibitors) sildenafil (Revatio ® ) ↑ sildenafil Co-administration of sildenafil with PAXLOVID is contraindicated for use in pulmonary hypertension due to the potential for sildenafil associated adverse events, including visual abnormalities hypotension, prolonged erection, and syncope [see Contraindications (4) ] . sildenafil, tadalafil, vardenafil ↑ sildenafil ↑ tadalafil ↑ vardenafil Dosage adjustment is recommended for use of sildenafil, tadalafil or vardenafil with PAXLOVID when used for erectile dysfunction.
Paxlovid
Viagra, Revatio
Paxlovid is a medicine used to treat mild to moderate COVID-19 in adults. It helps prevent severe illness, hospitalization, or death in people at high risk.
Sildenafil is a medicine used to treat erectile dysfunction (ED) in men. It helps increase blood flow to the penis to get and keep an erection.
Paxlovid treats mild to moderate COVID-19 in adults. You must be at high risk of your illness becoming severe. This includes needing to go to the hospital or possibly dying from COVID-19. Paxlovid is not for preventing COVID-19 before or after exposure.
Sildenafil is used to treat erectile dysfunction (ED), also known as impotence, in men. ED is when you cannot get or keep an erection firm enough for sex. Sildenafil helps by increasing blood flow to the penis when you are sexually stimulated.
Paxlovid contains two medicines, nirmatrelvir and ritonavir. Nirmatrelvir stops the virus from multiplying in your body. Ritonavir helps nirmatrelvir stay in your body longer so it can work better.
Sildenafil belongs to a class of drugs called PDE5 inhibitors. It works by relaxing the muscles and increasing blood flow to the penis during sexual stimulation. This helps you get and keep an erection.
- • Change in taste
- • Diarrhea
- • Headache
- • Flushing (redness of the skin)
- • Upset stomach
- • Abnormal vision (blurred vision, changes in color vision)
- • Nasal congestion (stuffy nose)
- COVID-19 22,774
- COVID-19 coming back 20,089
- Change in taste 7,316
- Diarrhea 4,003
- Feeling sick to your stomach 2,620
- Dyspnoea 7,729
- Headache 5,655
- Diarrhoea 4,447
- Nausea 3,984
- Death 3,873
Paxlovid can interact with many other medicines, causing serious or life-threatening problems. Before taking Paxlovid, tell your doctor about all the medicines you take. Your doctor may need to adjust the dose of your other medicines or monitor you more closely.
You should not take sildenafil if you are taking nitrates for chest pain, as this can cause a dangerous drop in blood pressure. If you have an erection that lasts longer than 4 hours, get medical help right away. Stop taking sildenafil and seek medical attention if you have a sudden loss of vision or hearing.
There is not enough information about nirmatrelvir's safety during pregnancy. Studies on ritonavir in pregnant women have not shown an increased risk of birth defects. Talk to your doctor about the risks and benefits of taking Paxlovid if you are pregnant or breastfeeding.
Sildenafil is not for use in women. It is not known if sildenafil can harm an unborn baby or pass into breast milk.
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How to Read This nirmatrelvir/ritonavir vs sildenafil Comparison
nirmatrelvir/ritonavir is classified in the Antiviral (Protease Inhibitor Combination) drug class, while sildenafil sits within the PDE5 Inhibitor class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, nirmatrelvir/ritonavir has 56,802 submissions while sildenafil has 25,688. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known major interaction flagged in FDA labeling, attributed to this combination makes sildenafil stay in your body longer and at higher levels, which can cause your blood pressure to drop too low.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot represent individual circumstances. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This registry does not provide medical, treatment, substitution, or medication-change directions for nirmatrelvir/ritonavir or sildenafil.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.