Antiviral medicines for flu and COVID-19 work best when they are started early, so timing matters more than almost anything else. If you are sick and at higher risk, call as soon as symptoms start rather than waiting to see if you get worse.
Flu: Tamiflu and Xofluza
Oseltamivir (Tamiflu) works best when started within 48 hours of the first symptoms. Baloxavir (Xofluza) is a single-dose option for many people with the same 48-hour window, but it is not recommended during pregnancy or breastfeeding; oseltamivir is the usual choice then. People at high risk, such as adults 65 and older, pregnant women and people with chronic heart, lung or kidney disease, may still benefit when treatment starts later, so call even if you are past two days.
COVID-19: Paxlovid
Nirmatrelvir with ritonavir (Paxlovid) is for adults at higher risk of severe illness and needs to start within 5 days of the first symptoms. It interacts with many common medicines, including some statins, blood thinners and heart rhythm medicines, so your prescriber will review everything you take, and the dose depends on your kidney function. Some people notice a temporary bitter taste.
Who counts as higher risk
Older age, diabetes, heart or lung disease, obesity, a weakened immune system and pregnancy all raise the risk of serious illness and make early treatment more valuable.
When to go to the emergency room instead
Trouble breathing, chest pain or pressure, confusion, bluish lips or face, or being unable to keep fluids down need emergency care, not an office visit.
Get help from Hope Integrative Medicine
If you have flu or COVID symptoms and are at higher risk, call us early so we can decide quickly whether an antiviral is right for you. Our primary care team in West Ashley sees patients in person and by telehealth across South Carolina, and new patients are often able to be scheduled within a week of requesting an appointment. Request an appointment.
This article is general health information and does not replace advice from your own provider. Never start, stop or change a medication without talking with your prescriber.
Frequently Asked Questions
For healthy adults, Tamiflu works best within 48 hours of the first symptoms. People at high risk, such as adults 65 and older, pregnant women and people with chronic heart, lung or kidney disease, may still benefit when started later, so call even if you are past two days.
Paxlovid needs to start within 5 days of the first COVID-19 symptoms, and it is meant for adults at higher risk of severe illness.
Paxlovid interacts with many common medicines, including some statins, blood thinners, heart rhythm medicines and some seizure and psychiatric medicines. Your prescriber reviews everything you take and may pause or adjust some during treatment.