Penicillins

Include ?-lactam ring in their structure
- reach bone, CSF, CNS in inflam (meningitis),

- Natural P : Benzyl P (PG)
-(G + cocci, G- cocci , G+bacilli , spirochetes)

Phenoxymethyl Pen (P V)
-More acid stable, same + some anaerobic MO
Methicillin , Nafcilin, Oxacillin, Dicloxacillin (xG-)
-penicillinase (?-lactamase )resistant P
-staphylococci
-methcillin used in lab only ,toxic
- Absorption decreased by food in stomach , destructed by acid so given 30-60 min before meal
Ampicillin , Amoxicillin
-are acid stable
- Spectrum same PG + G- bacilli
-Ampicillin choiced for G+bacilli( listeria monocyto)
-Amoxicillin not for enteritis due shigella or salmonella (low conc in intestinal crypt)
-Amoxicillin used prophylactically by dentists in prevention of bacterial endocarditis
-both in Rx respiratory infection


?-lactamase inhibitor
Clavulanic acid, salbactam, tazobactam

- Contain ?-lactam ring but don’t have sig antimicrobial activity
- Act after combination, protect Pen from ?-lactamase



-combination with ? lactamase inhibitor (clavulanic acid +Amoxicillin & sulbactam+ Ampicillin) protect them from enzymatic hydrolysis & extend spectrum



-combination with ? lactamase inhibitor (clavulanic acid +Amoxicillin & sulbactam+ Ampicillin) protect them from enzymatic hydrolysis & extend spectrum



-combination with ? lactamase inhibitor (clavulanic acid +Amoxicillin & sulbactam+ Ampicillin) protect them from enzymatic hydrolysis & extend spectrum