If allergic to pcn are you allergic to ampicillin?

Yes: Ampicillin is a beta lactam antibiotic- closely related to penicillin. It is part of the aminopenicillin family and is roughly equivalent to Amoxicillin in terms of spectrum and level of activity. I would avoid it until you have had a chance to get penicillin testing through your doctor.

Yes: Ampicillin is a penicillin. Studies in the past have shown that most people can loose penicillin allergy over time ( nearly 80% ten years or more after a reaction). Testing can be helpful to see if you lost the allergy, particularly with less severe rash reactions.

Yes: If you had an allergic reaction to penicillin it is likely you will have the same reaction if you take ampicillin.