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Bicillin L-A Side Effects

Generic Name: penicillin g benzathine

Note: This page contains information about the side effects of penicillin g benzathine. Some of the dosage forms included on this document may not apply to the brand name Bicillin L-A.

Not all side effects for Bicillin L-A may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to penicillin g benzathine: parenteral injection, parenteral powder for im injection or iv infusion, parenteral suspension for im injection

Side effects include:

Hypersensitivity reactions (rash, urticaria, serum sickness); local effects.

For Healthcare Professionals

Applies to penicillin g benzathine: intramuscular suspension


Frequency not reported: Injection site reactions (including pain, inflammation, lump, abscess, necrosis, edema, hemorrhage, cellulitis, hypersensitivity, atrophy, ecchymosis, skin ulcer), neurovascular reactions (including warmth, vasospasm, pallor, mottling, gangrene, numbness or cyanosis of the extremities, neurovascular damage)[Ref]


Frequency not reported: Skin eruptions (maculopapular to exfoliative dermatitis), pruritus, urticaria, laryngeal edema, fever, eosinophilia, hypersensitivity myocarditis, other serum sickness-like reactions (including chills, fever, edema, arthralgia, prostration), anaphylaxis (including shock, death), hypersensitivity reactions (including allergic vasculitis, pruritus, fatigue, asthenia, pain), Jarisch-Herxheimer reaction[Ref]

The Jarisch-Herxheimer reaction has been reported during syphilis treatment.[Ref]


Frequency not reported: Cardiac arrest, hypotension, tachycardia, palpitations, pulmonary hypertension, pulmonary embolism, vasodilation, vasovagal reaction, cerebrovascular accident[Ref]

Nervous system

Frequency not reported: Syncope, neuropathy, headache, tremors, dizziness, somnolence, abnormal taste perception, tinnitus, transverse myelitis, seizures, aseptic meningitis, coma, neurovascular reactions (including warmth, vasospasm, pallor, mottling, gangrene, numbness of the extremities, cyanosis of the extremities, neurovascular damage), myoclonus, seizures, auditory and visual hallucinations, decreased mentation, neurologic reactions[Ref]

Severe reactions (including myoclonus, seizures, auditory and visual hallucinations, and decreased mentation) have been reported with high dose penicillin therapy or in patients with renal dysfunction. Severe neurologic reactions were most often seen with penicillin doses of 18 million to 80 million units daily. These reactions frequently abated after discontinuation of penicillin. In several cases, penicillin was restarted at a lower dose with no further sequelae. In one review, the authors found that cerebral spinal fluid (CSF) penicillin levels were higher in patients with seizures than in those without. CSF penicillin levels ranged from 12 to 61 units/mL in the seizure group with the highest CSF concentrations, compared to 7.8 units/mL in the group without seizures. Neurologic reactions occurred frequently in patients with renal dysfunction.[Ref]


Onset of pseudomembranous colitis symptoms have been reported during or after antibacterial therapy.[Ref]

Frequency not reported: Clostridium difficile associated diarrhea, pseudomembranous colitis, nausea, vomiting, pancreatitis, intestinal necrosis, blood in the stool[Ref]


Frequency not reported: Hemolytic anemia, anemia, leukopenia, thrombocytopenia, lymphadenopathy[Ref]


A 28-year-old female developed jaundice, fever, epidermolysis, abnormal liver function tests, and cholestasis several days after receiving a single dose of penicillin intramuscularly. Her liver dysfunction continued for up to 18 months. She had taken acetaminophen concurrently but denied alcohol use.[Ref]

Frequency not reported: Increased SGOT, reversible hepatotoxicity, jaundice, prolonged cholestasis[Ref]


Quadriceps femoris fibrosis and atrophy have been reported following repeated intramuscular injections into the thigh.[Ref]

Frequency not reported: Joint disorder, periostitis, myoglobinuria, rhabdomyolysis, exacerbation of arthritis, quadriceps femoris fibrosis and atrophy[Ref]


Frequency not reported: Increased BUN, increased creatinine, renal failure, nephropathy[Ref]


Frequency not reported: Hypoxia, apnea, dyspnea[Ref]


Frequency not reported: Nervousness, confusion, anxiety, euphoria[Ref]


Frequency not reported: Blurred vision, blindness[Ref]


Frequency not reported: Neurogenic bladder, hematuria, proteinuria, impotence, priapism[Ref]


Frequency not reported: Diaphoresis, rash, peeling, mucosal ulceration, urticaria[Ref]


Frequency not reported: Fatigue, asthenia, pain, aggravation of existing disorders[Ref]


1. "Product Information. Bicillin L-A (penicillin)." Monarch Pharmaceuticals Inc, Bristol, TN.

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