I am taking azithromycin (as z-pack) for a sinus infection; finished course this morning and i am improved but still congested. will it keep working?

Yes: Z pac stars working after you finsh the pills- for the next five days. But z-pac is a over used drug , resistance is about25-40 %. If you are not a smoker and chronic respiratory/ dm , do not work in medical facility; it will work.

Long half life : Zithromax is a unique medicine that is taken for a shorter duration but continues to work for many days after taking the last pill. If one's symptoms continue to improve, no problem. If one's symptoms worsen after the last pill, time to see your doctor again.

Yes: If you are improving, the medicine stays in your system at a therapeutic level for a few days. However although it stays in longer, the level is not therapeutic. Do not forget to keep hydrated and use nasal saline.

No: Although Azithromycin is the most commonly used antibiotic prescribed in the us by general physicians, it is rarely recommended by ENT physicians. It has no effect against nthi (non-typable haemophilus influenzae), a very common bacterial cause of acute otitis media and acute sinusitis. 98% of acute sinusitis is viral. Is the diagnosis correct? Could you just have a viral infection?