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Procaine penicillin Side Effects

For the Consumer

Applies to procaine penicillin: intramuscular suspension

You should not use this medication if you are allergic to penicillin. Tell your doctor if you have ever had an allergic reaction to a cephalosporin antibiotic such as Ceftin, Cefzil, Omnicef, Keflex, and others.

Before using procaine penicillin, tell your doctor if you have asthma or a history of allergies, or kidney disease.

Do not inject this medication into a vein or life-threatening side effects may result.

Use this medication for the full prescribed length of time. Call your doctor if your infection does not improve, or if it gets worse while using procaine penicillin.

Tell your doctor about all other medications you use, especially gout medication, a blood thinner, a diuretic, a tetracycline antibiotic, or a non-steroidal anti-inflammatory drug (NSAID).

Procaine penicillin can make birth control pills less effective. Ask your doctor about using a non-hormone method of birth control (such as a condom, diaphragm, spermicide) to prevent pregnancy while using procaine penicillin. Hormonal forms of contraception (such as birth control pills, injections, implants, skin patches, and vaginal rings) may not be effective enough to prevent pregnancy during your treatment.

After you have finished your treatment with procaine penicillin, your doctor may want to do tests to make sure your infection has completely cleared up.

Get emergency medical help if you have any of these signs of an allergic reaction while taking procaine penicillin: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have a serious side effect such as:

  • diarrhea that is watery or bloody;

  • peeling skin , severe pain, or changes in skin color where the medicine was injected;

  • dizziness, joint or muscle pain;

  • fast or pounding heartbeats;

  • numbness, tingling, pain, swelling, or redness in your arms or legs;

  • confusion, agitation, depression, unusual thoughts or behavior;

  • chest pain, problems with vision or speech;

  • feeling like you might pass out;

  • fever, chills, dizziness, muscle pain, rapid breathing or heart rate;

  • uncontrolled muscle movements, problems with balance or walking;

  • pale skin, easy bruising or bleeding, unusual weakness;

  • sore throat, flu symptoms;

  • urinating less than usual or not at all;

  • rash or itching with swollen glands, joint pain, or general ill feeling; or

  • slow heart rate, weak pulse, fainting, slow breathing.

Less serious side effects of procaine penicillin may include:

  • pain where the injection was given;

  • vaginal itching or discharge;

  • white patches in your mouth or throat;

  • nausea, vomiting;

  • blurred vision, ringing in your ears;

  • headache, dizziness; or

  • mild skin rash,

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

For Healthcare Professionals

Applies to procaine penicillin: intramuscular suspension


Hypersensitivity side effects associated with penicillin have included skin rashes (ranging from maculopapular eruptions to exfoliative dermatitis), urticaria, and serum sickness-like reactions (including chills, fever, edema, arthralgia, and prostration). Anaphylaxis (severe and often fatal) and Jarisch-Herxheimer reaction (as with other treatments for syphilis) have been reported. Procaine toxicity manifestations and hypersensitivity reactions have been reported.[Ref]


Gastrointestinal side effects associated with penicillin G have included pseudomembranous colitis.[Ref]

The onset of pseudomembranous colitis symptoms may occur during or after treatment.[Ref]


Psychiatric side effects have included a syndrome manifested by a variety of central nervous system symptoms such as severe agitation with confusion, visual and auditory hallucinations, and a fear of impending death (Hoigne's syndrome) following procaine penicillin use. Other symptoms associated with this syndrome have included psychosis, seizures, dizziness, tinnitus, cyanosis, palpitations, tachycardia, and abnormal taste perception.[Ref]


Renal side effects associated with parenteral penicillin G have included nephropathy.[Ref]


Hematologic side effects associated with parenteral penicillin G have included hemolytic anemia, leukopenia, and thrombocytopenia.[Ref]

Nervous system

Nervous system side effects associated with parenteral penicillin G have included neuropathy.[Ref]


1. "Product Information. Bicillin C-R 900/300 (benzathine penicillin-procaine penicillin)." Wyeth Laboratories, Philadelphia, PA.

2. "Product Information. Penicillin G Procaine (procaine penicillin)." Monarch Pharmaceuticals Inc, Bristol, TN.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.