What are the possible side effects of
If you experience any of the following serious side effects, stop taking
penicillin and seek emergency medical attention:
An allergic reaction (shortness of breath; closing of your throat;
hives; swelling of your lips, face, or tongue; rash; or fainting);
seizures; severe watery diarrhea and abdominal cramps; or
unusual bleeding or bruising.
Other, less serious side effects may be more likely to occur. Continue
to take penicillin and talk to your doctor if you experience mild
nausea, vomiting, diarrhea, or abdominal pain; white patches on the
tongue (thrush/yeast infection); itching or discharge of the vagina
(vaginal east infection); black, "hairy" tongue or sore mouth or tongue.
Side effects other than those listed here may also occur. Talk to your
doctor about any side effect that seems unusual or that is especially
What other drugs will affect penicillin?
Some drugs may decrease the effects of penicillin and prevent it from
properly treating your infection. Before taking penicillin, tell your
doctor if you are taking any of the following drugs:
cholestyramine (Questran) or colestipol (Colestid); or another
antibiotic (for the same or for a different infection) such as
erythromycin (Ery-Tab, E-Mycin, E.E.S., others), tetracycline (Sumycin,
others), minocycline (Minocin), doxycycline (Doryx, Vibramycin, others),
or any other antibiotic.
Penicillin may decrease the effectiveness of birth control pills. Use a
second method of birth control while taking penicillin to protect
Penicillin increases the effects of methotrexate, and you may need a
dose adjustment during therapy with penicillin.
Penicillin also increases the side effects of allopurinol (Zyloprim)
and may cause a rash.
Probenecid (Benemid) increases the effects of penicillin. These drugs
may be used together for this purpose; however, be sure your doctor is
aware if you are taking probenecid. You may need a lower dose of
Drugs other than those listed here may also interact with penicillin.
Talk to your doctor and pharmacist before taking any prescription or