Penicillin G benzathine is used to treat a wide variety of bacterial infections. It may also be used to prevent certain bacterial infections (such as rheumatic fever). This medication is a long-acting penicillin antibiotic. It works by stopping the growth of bacteria.

This medication is given by injection into a large muscle as directed by your doctor. The dosage is based on your medical condition and response to treatment. Children's dosage is also based on age and weight.

If you are using this medication at home, learn all preparation and usage instructions from your health care professional. Do not inject into or near an artery, nerve, or vein. See also Warning section. Change the injection site each time to lessen injury to the muscle. Before using, check this product for particles or discoloration. If either is present, do not use the liquid. Learn how to store and discard medical supplies safely.

For the best effect, follow your doctor's directions for when to receive this antibiotic, and make sure to not miss any doses.

Continue to receive this medication for the full time prescribed, even if symptoms disappear after a few days. Stopping the medication too early may result in a return of the infection.

Tell your doctor if your condition lasts or gets worse.

Pain at the injection site, nausea, or vomiting may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• joint/muscle pain
• vision changes
• signs of a new infection (such as sore throat that doesn't go away, fever, chills)
• easy bruising/bleeding
• unusual tiredness
• mental/mood changes (such as confusion, hallucinations, depression, agitation)

This medication may rarely cause a severe intestinal condition due to a bacteria called C. difficile. This condition may occur during treatment or weeks to months after treatment has stopped. Tell your doctor right away if you develop:

• diarrhea that doesn't stop
• abdominal or stomach pain/cramping
• blood/mucus in your stool

If you have these symptoms, do not use anti-diarrhea or opioid products because they may make symptoms worse.

Use of this medication for prolonged or repeated periods may result in oral thrush or a new yeast infection. Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge, or other new symptoms.

When used to treat syphilis and certain other infections, this medication may cause a reaction that occurs several hours after starting treatment and can last up to 24 hours. Tell your doctor right away if you have any of these symptoms: headache, fever/chills, sweating, joint/muscle pain, fast heartbeat, dizziness, worsening of skin sores or other disease symptoms.

Get medical help right away if you have any very serious side effects, including:

• pain/redness/swelling/numbness/weakness of arms/legs
• change in skin color near the injection site or on arms/legs
• severe pain/peeling skin at the injection site
• muscle cramps/weakness around the injection site
• inability to move (paralysis)
• chest pain
• swollen lymph nodes
• severe stomach/abdominal pain
• nausea/vomiting that doesn't stop
• yellowing eyes/skin
• irregular heartbeat
• seizures
• pink/bloody/dark urine
• signs of kidney problems (such as a change in the amount of urine)

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before using this medication, tell your doctor or pharmacist if you are allergic to it; or to other antibiotics (such as other penicillins, cephalosporins); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• kidney disease

This medication may cause live bacterial vaccines (such as typhoid vaccine) to not work well. Tell your health care professional that you are using this medication before having any immunizations/vaccinations.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This drug passes into breast milk in small amounts. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

A product that may interact with this drug is:

• methotrexate

This medication may interfere with certain lab tests (including certain urine glucose tests), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: seizures.

Lab and/or medical tests (such as complete blood count, kidney function, blood cultures) may be done if you are using this medication for a long time. Keep all medical and lab appointments.

It is important to get each dose of this medication as scheduled. If you miss a dose, ask your doctor or pharmacist right away for a new dosing schedule. Do not double the dose to catch up.

Store in the refrigerator or as directed by your pharmacist. Do not freeze. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.