Penicillin G Benzathine Side Effects

Medically reviewed by Drugs.com. Last updated on Nov 30, 2023.

Applies to penicillin g benzathine: intramuscular suspension.

Precautions

It is very important that your doctor check your or your child's progress closely while receiving the medicine to make sure this medicine is working properly. Blood tests may be needed to check for unwanted effects.

This medicine may cause a serious allergic reaction, called anaphylaxis, which can be life-threatening and requires immediate medical attention. Tell your doctor right away if you or your child has a rash, itching, hoarseness, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth after receiving this medicine.

This medicine may cause serious skin reactions, including Stevens-Johnson syndrome, toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms (DRESS), or acute generalized exanthematous pustulosis (AGEP). Check with your doctor right away if you or your child has black, tarry stools, blistering, peeling, loosening of the skin, chest pain, chills, cough, diarrhea, fever, itching, joint or muscle pain, painful or difficult urination, red irritated eyes, red skin lesions, often with a purple center, sore throat, sores, ulcers, or white spots in them mouth or on the lips, swollen glands, trouble breathing, unusual bleeding or bruising, or unusual tiredness or weakness.

Call your doctor if your symptoms do not improve or get worse.

This medicine may cause diarrhea, and in some cases it can be severe. It may occur 2 months or more after you stop receiving this medicine. Do not take any medicine to treat diarrhea without first checking with your doctor. Diarrhea medicines may make the diarrhea worse or make it last longer. If you have any questions about this or if mild diarrhea continues, or gets worse, check with your doctor.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Serious side effects

Along with its needed effects, penicillin g benzathine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking penicillin g benzathine:

Other side effects

Some side effects of penicillin g benzathine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

See also:

For healthcare professionals

Applies to penicillin g benzathine: intramuscular powder for injection, intramuscular suspension.

Local adverse events

• 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 of the extremities, cyanosis of the extremities, neurovascular damage)^[Ref]

Hypersensitivity

• Frequency not reported: Hypersensitivity reactions (including skin eruptions [maculopapular to exfoliative dermatitis], urticaria, laryngeal edema, fever, eosinophilia, hypersensitivity myocarditis, other serum sickness-like reactions [including chills, fever, edema, arthralgia, prostration], anaphylactic/anaphylactoid reaction [including shock, death], allergic vasculitis, pruritus, fatigue, asthenia, pain)^[Ref]

Cardiovascular

• Frequency not reported: Cardiac arrest, hypotension, tachycardia, palpitations, pulmonary hypertension, pulmonary embolism, vasodilation, vasovagal reaction, cerebrovascular accident, cyanosis^[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, decreased mentation, neurologic reactions^[Ref]

Severe reactions (including myoclonus, seizures, auditory and visual hallucinations, 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 1 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.

A syndrome characterized by various central nervous system symptoms (e.g., severe agitation with confusion, visual and auditory hallucinations, fear of impending death [Hoigne's syndrome]) has been reported after administration of this drug. Other symptoms associated with this syndrome have included psychosis, seizures, dizziness, tinnitus, cyanosis, palpitations, tachycardia, and abnormal taste perception.^[Ref]

Gastrointestinal

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

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

Hematologic

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

Hepatic

• Frequency not reported: Increased AST, jaundice, cholestasis, abnormal liver function tests^[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 IM. Her liver dysfunction continued for up to 18 months. She had taken acetaminophen concurrently but denied alcohol use.^[Ref]

Musculoskeletal

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

Quadriceps femoris fibrosis and atrophy have been reported after repeated IM injections into the anterolateral thigh.^[Ref]

Renal

• Frequency not reported: Increased BUN, increased creatinine, renal failure, nephropathy, acute interstitial nephritis^[Ref]

Respiratory

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

Psychiatric

• Frequency not reported: Nervousness, confusion, anxiety, euphoria, auditory and visual hallucinations, agitation, fear of impending death, psychosis^[Ref]

Ocular

• Frequency not reported: Blurred vision, blindness^[Ref]

Genitourinary

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

Dermatologic

• Frequency not reported: Diaphoresis, rash, peeling, mucosal ulceration, urticaria, epidermolysis

Beta-lactam antibiotics:

• Frequency not reported: Severe cutaneous adverse reactions (including Stevens-Johnson syndrome, toxic epidermal necrolysis, drug rash with eosinophilia and systemic symptoms [DRESS syndrome], acute generalized exanthematous pustulosis)^[Ref]

Other

• Frequency not reported: Fatigue, asthenia, pain, aggravation of existing disorder, Hoigne's syndrome^[Ref]

Immunologic

• Frequency not reported: Jarisch-Herxheimer reaction

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

Further information

Penicillin g benzathine side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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