Pfizer Incorporated is a major pharmaceutical company, which ranks number two in sales. The company is based in New York City. It produces the number-one selling drug Lipitor (atorvastatin, used to lower blood cholesterol); the oral antifungal medication Diflucan (fluconazole), the long-acting antibiotic Zithromax (azithromycin), the well-known erectile dysfunction drug Viagra (sildenafil citrate), and the anti inflammatory Celebrex (celecoxib) (also known as Celebra in some countries outside USA and Canada, mainly in South America).