Aminopenicillins

Ampicillin – IV/PO

Amoxicillin – PO (better absorbed)

Coverage:  like natural PCN (Strep, Enterococcus, Listeria) plus:
E. coli (60%)
Proteus mirabilis
H. influenzae (70%)

Clinical Uses
Otitis media (Drug of Choice)
Listeria monocytogenes
Enterococcus (if susceptible)
Alternative for Strep. species
Community-acquired upper respiratory infections (sinusitis)

Penicillinase Resistant Penicillins

Nafcillin (IV)
Oxacillin (IV)
Dicloxacillin (PO)

Cover Staphylococcus aureus (MSSA) and most Streptococcus

Usually drug of choice (DOC) for serious methicillin-susceptible staph infections (along with cefazolin)

Also used for simple cellulitis