Penicillin's classification

A. Natural penicillins (narrow-spectrum, β-lactamase susceptible penicillins)
1) Parenteral administration: Benzylpenicillin (penicillin ‘G’)
2) Oral administration: Phenoxymethylpenicillin (penicillin ‘V’)
B. Semi-synthetic penicillins
1. Very narrow-spectrum, β-lactamase resistant penicillins ( Antistaphyloccal)
2. Broad spectrum, β-lactamase susceptible penicillins
a) Aminopenicillins
b) Mecillinam (active to gram-negative (G-) flora, inefficient against pseudomonads)
c) Carboxypenicillins (antipseudomonal)
d) Ureidopenicillins (antipseudomonal)
3. Other β-lactam drugs
4. β-lactamase inhibitor
5. Combined drugs of penicillin and β-lactamase inhibitors

1. Penicillins

A. Natural penicillins (narrow-spectrum, B-lactamase susceptible penicillins)
1) Parenteral administration: Benzylpenicilin (penicillin ‘G’)
2) Oral administration: Phenoxymethylpenicilin (penicillin V’)
B. Semi-synthetic penicillins
1. Very narrow-spectrum, B-lactamase resistant penicillins ( Antistaphyloccal)
+ Oxacilin
+ Dicloxacilin
+ Flucloxacillin
2. Broad spectrum, B-lactamase susceptible penicillins
a) Aminopenicilins

+ Amoxycillin
b) Mecillinam (active to gram-negative (G-) flora, inefficient against
pseudomonads)
+ Pivmecillinam
e) Carboxypenicillins (antipseudomonal)
+ Carbenicillin

s (antipseudomonal)
Azlocillin
Mezlocilin
+ Piperacillin
3. Other B-lactam drugs
+ Monobactam (aztreonam)
+ Carbapenems (imipenem and meropenem)
4. B-lactamase inhibitors
+ Sulbactam
+ Tazobactam
+ Sodium or potassium clavulanate
5. Combined drugs of penicillin and B-lactamase inhibitors
+ Amoxiclav (amoxicilin + potassium clavulanate)
‘© Unasin (ampicillin + sulbactam)