Extended-spectrum penicillin is a group of antibiotics that has the widest antibacterial spectrum of all penicillins. It is also called antipseudomonal penicillins. This group includes the carboxypenicillins and the ureidopenicillins. Note that aminopenicillins, in contrast, do not have activity against Pseudomonas species, as their positively-charged amino group does not hinder degradation by bacterially-produced beta-lactamases. 
- ^ Comprehensive Pharmacy Review, Leon Shargel, 6th edition, p917
- ^ Golan, David E. Principles of Pharmacology (2 ed.). Lippincott Williams & Wilkins. p. 610. ISBN 1608312704.