Motrin 800 mg
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.
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.