Dentist and her pharmacy: Two companies negligence?

A friend was given a prescription for augmentin from her dentist, so she went to a pharmacy to fill it. After filling it and taking it home and taking her first pill, at work her co-workers noticed she starting getting a bad rash and then she had problems breathing. Come to find out, she had always been allergic to penicillin, and her dentist and her pharmacy knew it, but both over looked it and filled it anyways. She had no clue that augmentin was a form of penicillin. She has now been diagnosed with Stevens-Johnson syndrome as a result of this. Does she have a firm case?

[AFFA]

I wish to inform you that as dentist has after knowledge that medicine will not be suitable for you had still prescribed the medicine, therefore, a suit for medical malpractice can be filed. Further, the pharmacy shop may not be liable as they have to provide medicines prescribed by the doctor. However, if the pharmacy shop was associated in participating in the wrong acts of the dentist then the pharmacy store will be liable as an accomplice.

AFF

Details: The hygienist was the one that filled out the script. All the dentist did was sign it. At the pharmacy, i asked if they had her allergy on file and they said yes, i asked then how are you allowed to fill the prescription for someone if they are allergic to it, which they said the pharmacist over-rode the security and filled it anyways because she gave a consult, which never happened because we picked up the prescription through the drive-thru