Penicillin G benzathine and penicillin G procaine is a combination antibiotic that is used to treat infections caused by bacteria, including strep, pneumonia, and scarlet fever.

Penicillin G benzathine and penicillin G procaine may also be used for purposes not listed in this medication guide.

Tell your caregivers right away if you feel light-headed during the injection.

Penicillin G benzathine and penicillin G procaine is injected into a muscle by a healthcare provider.

This medicine is sometimes given in a single dose. The medicine may also be given every 2 to 3 days until your body temperature is normal for 48 hours.

Keep receiving the medicine even if your symptoms quickly improve. Skipping doses could make your infection resistant to medication.

You may need tests after treatment to make sure your infection has completely cleared.

If you need a medical, dental, or surgical procedure that includes use of a numbing medicine applied to one area of the body (local), tell the doctor ahead of time if you have recently received a penicillin G benzathine and penicillin G procaine injection.

You should not be treated with this medicine if you are allergic to penicillin or procaine.

Tell your doctor if you have ever had:

• an allergic reaction to a cephalosporin antibiotic (Keflex, Omnicef, and others);

• any type of allergy;

• asthma or breathing problems;

• a genetic enzyme deficiency called glucose-6-phosphate dehydrogenase (G6PD) deficiency;

• heart disease; or

• kidney disease.

Tell your doctor if you are pregnant or breastfeeding.

Call your doctor for instructions if you miss an appointment for your injection.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose may cause a seizure.

Avoid taking anti-diarrhea medicine without first asking your doctor. Diarrhea may be a sign of a new infection.

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Some side effects may occur if the medicine has been accidentally injected near a vein or nerve. Tell your caregivers right away if you feel light-headed or if you have:

• slow heart rate, weak pulse, slow breathing (breathing may stop);

• pain, numbness, tingling, burning, or feeling cold;

• pale or mottled skin, blue-colored lips, fingers, or toes;

• severe pain or swelling in your lower leg;

• weakness in your arms or legs; or

• blistering, peeling, discoloration, or painful skin changes where the medicine was injected.

Also call your doctor at once if you have:

• severe stomach pain, diarrhea that is watery or bloody (even if it occurs months after your last dose);

• confusion, agitation, hallucinations (seeing or hearing things that are not real), extreme fear;

• a seizure;

• pain, swelling, warmth, redness, bruising, bleeding, or a lump where the medicine was injected;

• pale or yellowed skin, bruising or bleeding, dark colored urine;

• urination problems; or

• signs of a new infection--fever, chills, mouth sores, vaginal itching or discharge.

Seek medical attention right away if you develop a serious condition called methemoglobinemia. Symptoms include headache, fast heartbeats, shortness of breath, feeling tired or light-headed, or skin that looks pale, gray, or blue-colored.

Common side effects of penicillin G benzathine and penicillin G procaine may include:

• nausea, vomiting, diarrhea;

• itching, sweating, allergic reaction;

• flushing (sudden warmth, redness, or tingly feeling);

• feeling anxious or nervous;

• headache, dizziness, drowsiness; or

• pain, swelling, or bruising where an injection was given.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your doctor about all your other medicines, especially:

• tetracycline; or

• probenecid.

This list is not complete and many other drugs may affect penicillin G benzathine and penicillin G procaine. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.