Most sinus infections are treated with amoxicillin-clavulanate as the first-choice antibiotic, typically prescribed for 5 to 7 days. But here’s what surprises many people: antibiotics aren’t always prescribed right away, and sometimes they’re not needed at all. The treatment you receive depends on how long your symptoms have lasted, how severe they are, and whether your infection is likely viral or bacterial.
Why You Might Not Get Antibiotics Right Away
The vast majority of sinus infections start as viral infections, and antibiotics don’t work against viruses. Clinical guidelines from the American Academy of Otolaryngology recognize this by giving doctors two equally valid options for uncomplicated bacterial sinus infections: prescribe antibiotics immediately or offer “watchful waiting,” where you hold off on antibiotics and see if your body clears the infection on its own.
Watchful waiting is only appropriate when you have reliable follow-up with your doctor so antibiotics can be started if things don’t improve within 7 days or if symptoms worsen at any point. This approach helps avoid unnecessary antibiotic use, which contributes to resistance and exposes you to side effects you may not need.
So how does your doctor decide the infection is bacterial in the first place? The key markers are symptoms that persist without improvement for at least 10 days after the onset of upper respiratory symptoms, or symptoms that initially get better and then worsen again within 10 days (sometimes called “double worsening”). The hallmark signs are thick, discolored nasal drainage along with nasal congestion, facial pain or pressure, or both.
The Standard Antibiotic Prescription
When antibiotics are warranted, amoxicillin-clavulanate is the go-to choice. The standard adult regimen is a 7-day course taken twice daily. This combination pairs a penicillin-type antibiotic with an ingredient that helps it work against bacteria that would otherwise resist it.
In areas where antibiotic-resistant bacteria are more common (specifically where penicillin-resistant strains exceed 10% of cases), your doctor may prescribe a higher-dose version of the same medication. The higher dose contains more amoxicillin per tablet but is otherwise the same regimen. A clinical trial published in JAMA compared standard and high doses and found both were used in a twice-daily, 7-day format.
Guidelines from the Infectious Diseases Society of America recommend 5 to 7 days of therapy for patients who respond well and have a low risk of resistance, though many prescriptions in practice run longer. If you’re not improving after 7 days on antibiotics, your doctor should reassess to confirm the diagnosis, look for other causes, and check for complications.
Alternatives for Penicillin Allergies
If you’re allergic to penicillin, the two main alternatives are doxycycline and respiratory fluoroquinolones. Both are considered appropriate first-line options for patients who can’t take penicillin-based drugs. Your doctor will choose between them based on your specific allergy history and other health factors. Fluoroquinolones carry boxed warnings for serious side effects including tendon damage and nerve problems, so they’re generally reserved for situations where other options aren’t suitable.
Nasal Steroid Sprays
Prescription or over-the-counter nasal corticosteroid sprays are commonly recommended alongside antibiotics, or even on their own for milder infections. These sprays reduce inflammation inside your nasal passages and sinuses, which helps drainage and relieves pressure. In clinical trials, people using nasal steroid sprays reached symptom improvement at a median of 6 days compared to 9.5 days for those using a placebo. Overall, about 73% of people using the sprays improved, versus 66% on placebo.
Studies also show a dose-response effect: higher doses tend to work better. The sprays are most effective when used consistently rather than on an as-needed basis. Common options available over the counter include fluticasone and budesonide sprays. In children with sinus infections being treated with antibiotics, adding a nasal steroid spray helped resolve coughing and nasal discharge earlier in the course of illness.
Decongestants and Over-the-Counter Relief
Oral decongestants can help relieve the stuffiness and pressure that make sinus infections miserable, but not all of them work equally well. Pseudoephedrine (the decongestant kept behind the pharmacy counter) significantly reduces nasal congestion. Phenylephrine, which is the decongestant found on open store shelves in most cold and sinus medications, performed no better than a placebo in a controlled clinical study. If you’re buying a decongestant specifically for congestion relief, pseudoephedrine is the more effective choice.
Neither decongestant helps with non-nasal symptoms like headache or fatigue. Over-the-counter pain relievers like ibuprofen or acetaminophen can help with facial pain and pressure. Decongestant nasal sprays (like oxymetazoline) offer fast relief but should be limited to 3 days to avoid rebound congestion that can make things worse.
Saline Nasal Irrigation
Rinsing your sinuses with salt water is one of the most consistently recommended home treatments. It physically flushes out mucus, bacteria, and inflammatory debris. You can use a squeeze bottle, neti pot, or bulb syringe with either isotonic saline (0.9% salt, matching your body’s natural concentration) or hypertonic saline (3% salt, which may draw out more fluid from swollen tissues). Interestingly, there’s no established guideline on which type is better or how many times a day to rinse. Most practitioners suggest twice daily as a reasonable starting point, though some patients find more frequent irrigation helpful during the worst days of an infection.
Always use distilled, sterile, or previously boiled water for nasal irrigation. Tap water can contain organisms that are harmless in your stomach but dangerous in your sinuses.
Warning Signs That Need Immediate Attention
Most sinus infections resolve with the treatments above, but certain symptoms signal complications that require urgent care. Swelling or redness around the eyes, pain when moving your eyes, or any vision changes suggest the infection may be spreading to the eye socket. Mental status changes, severe headache with nausea and vomiting, vertigo, seizures, or any new neurological symptoms point to possible spread toward the brain. These complications are rare but serious, and they require emergency evaluation rather than a standard office visit.
Symptoms that simply aren’t improving after a full course of antibiotics also warrant a follow-up. Your doctor may order imaging, take cultures to identify the specific bacteria involved, or refer you to an ear, nose, and throat specialist. Resistance patterns vary by region, and culture results can guide a switch to a more targeted antibiotic if the first choice isn’t working.