enzalutamide vs nirmatrelvir/ritonavir
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Side-by-side comparison of enzalutamide and nirmatrelvir/ritonavir. 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
Anticancer drugs apalutamide, enzalutamide ↓ nirmatrelvir/ritonavir Co-administration contraindicated due to potential loss of virologic response and possible resistance [see Contraindications (4) ].
Xtandi
Paxlovid
Xtandi contains enzalutamide. It is used to treat prostate cancer that is resistant to certain treatments.
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.
Xtandi is used to treat prostate cancer in men. It is for prostate cancer that keeps growing even when treated with hormone therapy or after surgery. Xtandi can treat prostate cancer that has spread or has not spread.
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.
Xtandi blocks the effect of hormones called androgens, like testosterone. Androgens can help prostate cancer cells grow. By blocking androgens, Xtandi can slow or stop the growth of prostate cancer.
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.
- • Muscle or joint pain
- • Feeling tired
- • Hot flashes
- • Constipation
- • Less hungry
- • Change in taste
- • Diarrhea
- Fatigue 10,159
- Death 7,667
- Malignant Neoplasm Progression 5,409
- Prostatic Specific Antigen Increased 4,295
- Asthenia 4,120
- 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
Xtandi can cause seizures. If you have a seizure while taking Xtandi, stop taking it permanently. Xtandi can also cause a condition called posterior reversible encephalopathy syndrome (PRES). If you experience PRES, stop taking Xtandi. Xtandi can harm an unborn baby, so men with partners who can get pregnant should use effective birth control during treatment and for 3 months after the last dose.
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.
Xtandi is not for use in women. It can cause harm to an unborn baby if taken by a pregnant woman. Men who are taking Xtandi and have partners who can get pregnant should use effective birth control during treatment and for 3 months after the last dose.
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.
How to Read This enzalutamide vs nirmatrelvir/ritonavir Comparison
enzalutamide is classified in the Androgen Receptor Inhibitor drug class, while nirmatrelvir/ritonavir sits within the Antiviral (Protease Inhibitor Combination) 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, enzalutamide has 31,650 submissions while nirmatrelvir/ritonavir has 56,802. 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 enzalutamide lowers the levels of nirmatrelvir/ritonavir in your body by speeding up how it is processed. this can prevent the medicine from fighting the virus effectively.. 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 enzalutamide or nirmatrelvir/ritonavir.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.