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Wycillin Side Effects

Generic Name: procaine penicillin

Note: This page contains side effects data for the generic drug procaine penicillin. It is possible that some of the dosage forms included below may not apply to the brand name Wycillin.

It is possible that some side effects of Wycillin may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

For the Consumer

Applies to procaine penicillin: injectable suspension

Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Black or hairy tongue; exaggerated reflexes; mild diarrhea; nausea or vomiting; pain, swelling, or redness at the injection site; twitching.

Seek medical attention right away if any of these SEVERE side effects occur while taking procaine penicillin (the active ingredient contained in Wycillin)

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); aggression or agitation; anxiety; bizarre behavior; blood in stools or urine; chest pain; chills; confusion; depression; extreme tiredness; fainting; fast heartbeat; fear of death; fever; flushing with lightheadedness or fainting; hallucinations; headache; itching; muscle pain; pounding in the chest; rapid breathing; seizures; severe diarrhea; stomach pain/cramps; vaginal irritation or itching; weakness; worsening of skin lesions.

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 (the active ingredient contained in Wycillin) 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.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.