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Important Note

The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.


(pen-ih-SILL-in G BEN-zuh-theen)



Penicillin G benzathine is an antibiotic used to treat a variety of bacterial infections.

How To Use

This drug is administered by a doctor or nurse and is injected into a large muscle. Antibiotics work best when the amount of medicine in your body is kept at a constant level. This is done by scheduling the doses at evenly spaced intervals. If more than one dose is required make sure you do not miss any doses. The number of doses depend on the type of infection. Continue to receive this medication until the fully prescribed treatment program is finished even if symptoms disappear after a few days. Stopping the medication too early may allow bacteria to continue to grow resulting in a relapse of the infection.

Side Effects

This medication may cause mild diarrhea, stomach upset, nausea, vomiting or irritation at injection site during the first few days as your body adjusts to the medication. If these symptoms persist or worsen, inform your doctor. Notify your doctor immediately if you develop: watery diarrhea, stomach cramps, fever, unusual bleeding or bruising, yellowing of the eyes or skin, unusual tiredness or weakness. Use of this medication for prolonged or repeated periods may result in a secondary infection (e.g., oral, bladder or vaginal yeast infection). In the unlikely event you have an allergic reaction to this drug, seek medical attention immediately. Symptoms of an allergic reaction include: wheezing, difficulty breathing, skin rash, hives, itching. If you notice other effects not listed above, contact your doctor or pharmacist.


Before using this drug tell your doctor your medical history especially: kidney disease, stomach/intestine diseases, allergies to penicillins or other antibiotics. Tell your doctor if you are pregnant before using this drug. This drug is excreted into breast milk. Consult your doctor before breast-feeding.

Drug Interactions

Tell your doctor of all the medications you take (prescription and nonprescription) especially probenecid, birth control pills, tetracyclines, certain live vaccines or aminoglycosides (e.g., gentamicin). This drug may interfere with the effectiveness of birth control pills. Discuss using other methods of birth control with your doctor. Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include nausea, vomiting, and diarrhea.


Certain urine glucose test results may be affected by this drug. Consult your doctor or pharmacist.

Missed Dose

It is important you receive all scheduled doses. Consult your doctor if you miss any.


Store this medication in a refrigerator between 36-46 degrees F (2-8 degrees C). Do not freeze.