Ticarcillin and carbenicillin - alphacarboxypenicillins
Many time combined with aminoglycosides
Vulnerable to inactivation by beta-lactamases
Food does not interfere with absorption of amoxicillin
But penicillin G should be given 1 h before or 2 h after a meal.
Amoxicillin has generally replaced ampicillin for oral use because amoxicillin is absorbed better, has fewer GI effects, and can be given less frequently.
Penicillins are distributed rapidly in the ECF of most tissues, particularly when inflammation is present.
All penicillins except nafcillin are excreted in urine and reach high levels in urine. Parenteral penicillin G is rapidly excreted (serum half-life 0.5 h), except for repository forms (the benzathine or procaine salt of penicillin G); these forms are intended for deep IM injection only and provide a tissue depot from which absorption takes place over several hours to several days. Benzathine penicillin reaches its peak level more slowly and is generally longer-acting than procaine penicillin.
Benzylpenicillin, also known as penicillin G, is an antibiotic used to treat a number of bacterial infections. This includes pneumonia, strep throat, syphilis, necrotizing enterocolitis, diphtheria, gas gangrene, leptospirosis, cellulitis, and tetanus. It is not a first-line agent for pneumococcal meningitis.
As an antibiotic, penicillin G is noted to possess effectiveness mainly against Gram-positive organisms. Some Gram-negative organisms such as Neisseria gonorrhoeae and Neisseria meningitidis are also reported to be susceptible to Penicillin G.