Many pharmacists are "doctors" in terms of holding a doctoral degree. If a pharmacist holds a Doctor of Pharmacy degree (Pharm.D) from an accredited university, they will carry the honorific, or title, of Dr. before their name.
Today, all pharmacy schools in the United States only offer Pharm.D degrees, but this wasn't always the case. At one point, all that was needed to become a registered pharmacist was a bachelor of science degree. This is why you may see "BS" after a pharmacists name instead of Pharm.D. If a pharmacist holds a BS degree and not Pharm.D degree, they will not carry the "Dr." before their name.