GENERIC NAME: ampicillin
BRAND NAMES: Omnipen; Polycillin; Principen
DRUG CLASS AND MECHANISM: Ampicillin is one of the most
widely
prescribed antibiotics. It is considered a penicillin and is a
close
relative of another penicillin, amoxicillin. Unlike penicillin,
ampicillin
and amoxicillin can penetrate and prevent the growth of certain
types of
bacteria, called gram-negative bacteria. Ampicillin is used
mainly to
treat infections of the middle ear, sinuses, bladder, kidney,
and
uncomplicated gonorrhea. It also is used intravenously to treat
meningitis
and other serious infections. Ampicillin was approved by the
FDA in 1963.
PRESCRIPTION: yes
GENERIC AVAILABLE: yes
PREPARATIONS: Tablets: 250mg; 500mg. Oral suspension:
100 mg/mL;
125 mg/5mL; 250 mg/5mL.
STORAGE: Tablets should be kept between 15°C
(59°F) and 30°C (86°F). The solution should be kept
refrigerated, and
can be used for up to 14 days after it is reconstituted by the
pharmacist.
It must be shaken before each use and should be kept well
sealed.
PRESCRIBED FOR: Oral ampicillin (or amoxicillin) is
effective
against susceptible bacteria causing infections of the middle
ear,
sinuses, bladder, and kidney. Only mild to moderate infections
are treated
with oral ampicillin. Bacteria against which ampicillin often
is effective
include: enterococci, Listeria monocytogenes, Neisseria
gonorrhoeae,
Neisseria meningitidis, some Hemophilus influenzae, Gardnerella
vaginalis,
Bordetella pertussis, and some E. coli, Proteus mirabilis,
Salmonella, and
Shigella. Susceptibilities of bacteria to antibiotics vary from
location
to location. Thus, some doctors may use ampicillin or
amoxicillin first
for some infections, whereas other doctors may use more
"broad-spectrum"
antibiotics.
DOSING: Food in the stomach reduces how much and how
quickly
ampicillin is absorbed. Administration should be either 1 hour
prior to or
2 hours following a meal for maximal absorption. However, for
persons who
experience nausea or stomach distress after taking ampicillin,
it may be
taken with meals. Ampicillin most often is given four times a
day for 7 to
14 days. When used to treat gonorrhea, it is given as a single
large dose
(for example, seven 500mg capsules) with probenecid. The
probenecid slows
down the elimination of the ampicillin so that the ampicillin
remains in
the body longer.
DRUG INTERACTIONS: Probenecid (Benemid), causes an
increase in
the amount of ampicillin in the body. This interaction may be
used to
advantage. (See Dosing.) Use of ampicillin with allopurinol can increase the
incidence of drug-related skin rash. Very high doses of
ampicillin (at
least 1 gram or 1000 mg) can decrease the effect of atenolol
(Tenormin) by
decreasing its concentration in the blood. Similarly,
ampicillin, even in
normal doses, can decrease the effectiveness of birth control
pills by
decreasing the blood concentrations of the estrogens in the
birth control
pills.
PREGNANCY: Ampicillin is considered safe during
pregnancy.
NURSING MOTHERS: Ampicillin
is excreted in breast milk.
No side
effects have been reported in nursing infants whose mothers
have taken
ampicillin. Concern for side effects such as allergic
reactions, of
course, exist. Thus, physicians weigh the potential risk of
allergy versus
the benefits.
SIDE EFFECTS: Allergic reactions are relatively common
side
effects during therapy with any of the penicillins. These
reactions can
range from rashes to anaphylaxis, a severe condition in which
there may be
shock and even death. Rashes occur more frequently with
ampicillin than
with the other penicillins. The incidence of rash with
ampicillin seems to
be higher in patients with viral illnesses, such as
mononucleosis.
Patients with a history of allergic reaction to any other
penicillin
should not receive ampicillin. Persons who are allergic to the
cephalosporin class of antibiotics which is more distantly
related to the
penicillins (e.g., Ceclor, Keflex, Cefzil) may or may not be
allergic to
penicillins.
Nausea, vomiting, loss of appetite, diarrhea, and abdominal
pain are
commonly reported gastrointestinal side effects during
ampicillin therapy,
but are rarely severe. Diarrhea appears to occur more
frequently with
ampicillin than with the other penicillins.
Last Editorial Review: 12/31/1997
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
 |
 |
From the Doctors at MedicineNet.com  |
|
|
- amoxicillin, Amoxil, Dispermox, Trimox - Learn more about amoxicillin, including a description, generic and brand names, drug class and mechanism, preparations, storage, reasons for prescription, dosing, effect on pregnancy and nursing mothers, and common side effects. Source:MedicineNet
- Clostridium Difficile Colitis (Antibiotic-Associated Colitis, C. difficile colitis) - Learn about clostridium difficile, or C. difficile the most common gut bug infection and growing epidemic. C. difficile symptoms include bloody diarrhea, fever, severe abdominal pain. Source:MedicineNet
- penicillin V (phenoxymethyl penicillin), Pen-Vee-K, Veetids - Source:MedicineNet
- Read 28 more ampicillin related articles ...
|
| |
|
Back to Medications Index
Specialty RSS
