at number 22, pharmacy faux pas. mareena silva is six weeks pregnant. she picks up a prescription for antibiotics at the pharmacy. she takes the medicine. and then sees the label is wrong. >> i came back and i looked at the bottle, and it wasn't my name. >> the pharmacy has given mareena a prescription meant for another woman who was the same last name and a similar first name. the medicine isn't an antibiotic. it's actually methotrexate, a drug that has the potential to terminate pregnancies. >> you never, ever want to give a drug like that to a pregnant patient. >> this is my first child. so it's really difficult to deal with. maybe we could have deformities. there's a lot that goes with it. >> things get hectic behind the prescription counter. an onslaught of phones ringing, messages, patients coming in. pharmacists pull medications from the shelves. you may pull the wrong drug, the wrong strength. we're dealing with a dangerous situation. we don't want to take the wrong medication. >> at neighborhood pharmacies every year 30 million prescriptions are