Need Medical Alert Jewelry; Appropriate Abbreviations

Patient: I am in need of a Medical Alert. I have Anaphylaxis with the following antibiotics: Penicillin, Ceclore, Rocefin, Pediazole, Duricef and Lorabid. The problem I am having is that there is limited space for engraving. Is there a safe way to abbreviate these medications by type or something similar?

Symptoms: Anaphylaxis

Doctor: The above mentioned medicines can be grouped under three categories of antibiotics namely, ‘╬▓-lactam’, ‘Macrolide’ and ‘Sulfa’. You may mention at least the group names if not the individual medicines, due to space constrain.