Who discovered penicillin?
In 1928, Alexander Fleming noted that
mold belonging to the genus Penicillium inhibited the growth of bacteria.
Fleming called this unknown antibacterial substance penicillin. Ten years later,
a group at Oxford University began to investigate penicillin in laboratory mice.
Penicillin was hailed as a miracle drug and saved countless lives in World War
What are penicillin antibiotics?
Penicillins are antibiotics used to treat bacterial infections that are
derived from the antibiotic penicillin.
What are the uses for penicillin antibiotics?
Today, many derivatives of penicillin have been developed that inhibit more
types of bacteria than the original life-saving drug. Penicillin itself is
- streptococci (including Streptococcus pneumoniae),
- Peptococcus, and
staphylococci now are resistant to penicillin.
Other penicillin antibiotics are
- H. influenzae,
- E. coli, pneumococci,
- certain strains of
- Pseudomonas aeruginosa, and
- many other
types of bacteria.
Penicillin antibiotics are used to treat many types of infections caused by
susceptible bacteria. They are used to treat
infections of the middle ear,
sinuses, stomach and intestines, bladder, and kidney. They also are used for
- blood infections (sepsis),
- uncomplicated gonorrhea,
- endocarditis, and
- other serious infections.
What are examples of penicillin antibiotics available in the US?
- penicillin V
- penicillin G (Pfizerpen, Permapen)
- amoxicillin (Amoxil)
- amoxicillin/clavulonate (Augmentin)
- ampicillin (Unasyn)
- nafcillin (Nallpen)
- oxacillin (Bactocill)
- dicloxacillin (Dycill, Dynapen are discontinued brands in the US; generic is
- cloxacillin (discontinued in the US)
- piperacillin (Pipracil)
- piperacillin/tazobactam (Zosyn)
- ticarcillin (Ticar) (Discontinued in the US; ; generic is not available))
- ticarcillin/clavulonate (Timentin) (Discontinued in the US and a generic is
What are the side effects of penicillin antibiotics?
Side effects of penicillin antibiotics include
- abdominal pain,
- easy bruising,
- rash, and
- allergic reactions.
Individuals who are allergic to the cephalosporin class of antibiotics, which
are related to the penicillins, for example, cefaclor (Ceclor), cephalexin
(Keflex), and cefprozil (Cefzil), may or may not be allergic to penicillins.
Serious but rare reactions include
- kidney problems,
- oral fungal infections,
- severe allergic reactions (anaphylaxis), and
- low blood platelet levels (thrombocytopenia) or red blood cell count.
Like other antibiotics, penicillin antibiotics can alter the normal bacteria
in the colon and encourage overgrowth of some bacteria such as Clostridium
difficile, which causes inflammation of the colon (C. difficile colitis or
Signs and symptoms of C. difficile colitis include
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What drugs interact with penicillin antibiotics?
Penicillin antibiotics have few important drug interactions.
- Probenecid (Benemid) causes an increase in the amount of penicillins in the
body by preventing excretion of penicillin by the kidneys.
- Combining ampicillin with allopurinol (Zyloprim) can increase the incidence
- Penicillin antibiotics may reduce the effect of BCG live vaccine and typhoid
What formulations of penicillin antibiotics are available?
Penicillin antibiotics are available as
- powder for oral suspension, and
- powder for injection.
Are penicillin antibiotics safe to take during pregnancy or while
- Penicillin antibiotics are considered safe to use
small amounts of penicillins pass into breast milk they are considered safe to
use while breastfeeding.
How do penicillin antibiotics work?
Penicillin antibiotics stop bacteria from multiplying by preventing bacteria
from forming the walls that surround them. The walls are necessary to protect
the bacteria from their environment, and to keep the contents of the bacterial
cell together. Bacteria cannot survive without a cell wall. Penicillin
antibiotics are most effective when bacteria are actively multiplying and
forming cell walls.