Do you need antibiotics for a sore throat or strep?

Almost always no. According to the CDC, most sore throats are caused by viruses, the same ones behind colds and flu, and antibiotics do not work on viruses: they do not make you better sooner and they can cause side effects. So anyone searching for a sore throat antibiotic first needs to know what is causing it.

Antibiotics are the right treatment when the cause is group A streptococcus (strep). You cannot tell the difference just by looking at the throat. It is decided from your history, an exam and, when needed, a test. For symptoms and home care, read sore throat; this guide focuses on the antibiotic decision.

A widely used clinical tool, known as the Centor criteria (and its modified version that adds age), gathers the clues that make strep more likely. It helps decide whether a test is worthwhile; it is not a diagnosis by itself:

These clues make strep less likely, and then an antibiotic almost never helps:

Many causes of sore throat look alike. That is why the CDC and IDSA guidelines recommend confirming strep with a rapid swab test or a throat culture before treating it with antibiotics, rather than treating based on how the throat looks.

If the doctor suspects strep, we give you a lab order for the test at a lab near you and she goes over the result with you. If it is positive and appropriate, she prescribes and we send your prescription to your pharmacy. If it is negative, she explains what comes next, which can include a confirmation culture, especially in children, and how to feel better in the meantime.

When strep is confirmed, an antibiotic helps you feel better a little sooner, makes you less contagious, and helps prevent uncommon but serious complications such as rheumatic fever and throat abscesses. The CDC lists penicillin or amoxicillin as the first choice, for about 10 days; if you are allergic to penicillin there are other options, so tell the doctor. It matters to finish the full course even if you feel better within a few days.

On an antibiotic, the CDC advises staying home until you have been on treatment for at least 12 hours and have no fever. To understand how these medicines work, read antibiotics by telehealth.

A viral sore throat usually gets better on its own in about a week. In the meantime, the doctor can guide you on what does help:

If you are a teenager or young adult and, besides the sore throat, you have deep tiredness, a lingering fever and swollen lymph nodes, it may be mononucleosis, which is viral and not treated with antibiotics. Allergies, reflux, dry air and smoke can also irritate the throat. Ruling these out is part of the assessment, and the doctor can request tests through a lab order when needed.

You are seen by Dr. Diana Nieves Castro, a general practice physician licensed in Puerto Rico, in English or Spanish. We evaluate, diagnose and treat; if needed, we give you a lab order. We see all ages.

It is a doctor visit, with the same price for every age and no membership. There is no extra charge for a prescription, and a doctor's note after your visit is included. You are charged when you request the visit, with a full refund if the clinic can't see you. See pricing. The service is run by The Health Initiative, a nonprofit.

This helps the doctor decide quickly and safely:

The doctor sees children of all ages. On video she checks the throat, neck and symptoms with your help on camera. If she suspects strep, we give you the lab order for the test, and if appropriate she prescribes with the dose based on your child's weight. Patients under 21 need a parent or legal guardian on camera with photo ID. See online doctor visits for kids.

In Puerto Rico, as in the rest of the United States, oral antibiotics are dispensed only with a prescription. The CDC advises against saving antibiotics for later or taking ones prescribed for someone else: they do not treat a virus, they can cause rash, nausea, diarrhea or allergic reactions, and they help bacteria become resistant. If you have a sore throat and think you need an antibiotic, request a visit online 24/7 and the doctor will assess you.