Will macrobid treat sinus infection?

No. Macrobid (nitrofurantoin) is not used to treat sinus infections. It’s designed for urinary tract infections and doesn’t reach effective levels in the sinuses, so it’s not appropriate for acute rhinosinusitis.

If you have sinus symptoms (nasal congestion, facial pain, discharge) that are lasting more than about 10 days, getting worse, or you have a high fever, see a clinician. They may prescribe a different antibiotic that works systemically—for example, amoxicillin-clavulanate, doxycycline (if you can’t take penicillin), or another option depending on allergies and pregnancy.

Important safety notes:
- Do not use nitrofurantoin for sinus infections.
- Nitrofurantoin can cause side effects (GI upset, dark urine, rarely lung or liver issues) and is not recommended in certain situations (kidney impairment with low creatinine clearance, late pregnancy, G6PD deficiency, etc.).
- Always use antibiotics only under a clinician’s advice.

If you’d like, tell me your symptoms, any allergies, and pregnancy status, and I can summarize typical sinusitis treatment options.