[Mel]

I believe this is an antibiotic, just need to make sure. Thanks.

Yes, it appears to be Pfizer's Zithromax (azithromycin) 250 mg capsule. Some info from Drugs.com Advanced Consumer Information:

"Azithromycin is used to treat bacterial infections in many different parts of the body. It is also used to prevent Mycobacterium avium complex (MAC) disease in patients infected with the human immunodeficiency virus (HIV). It works by killing bacteria or preventing their growth. However, this medicine will not work for colds, flu, or other viral infections. Azithromycin may be used for other problems as determined by your doctor."