Penicillin G Benzathine: Uses, Dosage, and Side Effects Explained

Summary of Key Points

Penicillin G benzathine is an antibiotic used to treat a variety of bacterial infections, including syphilis, streptococcal pharyngitis, and rheumatic fever. It works by stopping the growth of bacteria. This medication is administered via injection, typically by a healthcare professional. Always consult your doctor before starting or adjusting your dose. You can also schedule a telemedicine appointment with one of our providers for personalized care.

Names of Medication

US Brand Name: Bicillin L-A (Penicillin G benzathine)

The generic name is the official name of the medication, not associated with any specific brand. In this case, the generic name is listed in parentheses.

Pharmacologic Category

Penicillin Antibiotics

Penicillin G Benzathine Dosage

Penicillin G benzathine is used to treat several bacterial infections. Below are the recommended doses for adults. Always consult your healthcare provider before making any changes to your medication. You can also schedule a telemedicine visit with one of our providers for guidance.

1. Rheumatic Fever Prophylaxis: 1.2 million units intramuscularly every 3 to 4 weeks.
2. Syphilis (Primary, Secondary, and Early Latent): 2.4 million units intramuscularly as a single dose.
3. Syphilis (Late Latent or Tertiary): 2.4 million units intramuscularly once a week for 3 weeks.
4. Streptococcal Pharyngitis (Strep Throat): 1.2 million units intramuscularly as a single dose.
5. Bacterial Endocarditis Prophylaxis: 1.2 million units intramuscularly every 3 to 4 weeks.
6. Skin Infections: 1.2 million units intramuscularly as a single dose.
7. Pneumonia: 1.2 to 2.4 million units intramuscularly as a single dose, depending on severity.
8. Osteomyelitis: 2.4 million units intramuscularly once a week for 3 to 4 weeks.
9. Meningitis: 2.4 million units intramuscularly once a week for 3 weeks.
10. Anthrax: 1.2 to 2.4 million units intramuscularly as a single dose.
11. Diphtheria: 1.2 million units intramuscularly as a single dose.

Dosage Forms and Strengths

Penicillin G benzathine is available in the following injection forms:

1. Injection: 600,000 units/mL in a 1 mL syringe
2. Injection: 1.2 million units/mL in a 2 mL syringe
3. Injection: 2.4 million units/mL in a 4 mL syringe

Administration Instructions for Penicillin G Injection

Penicillin G benzathine is administered as an intramuscular injection, typically into the buttock or thigh. This medication should only be given by a healthcare professional. If you are receiving this medication at home, follow your healthcare provider’s instructions carefully. Do not inject into a vein or near a nerve, as this can lead to serious side effects. If you have any concerns or questions, schedule a telemedicine visit with one of our providers.

Penicillin G Side Effects and Adverse Reactions

Like all medications, Penicillin G benzathine can cause side effects. While not everyone will experience them, it’s important to be aware of potential reactions. If you notice any severe or unusual symptoms, contact your healthcare provider immediately or schedule a telemedicine appointment with us.

1. Common Side Effects: Mild pain, swelling, or redness at the injection site; nausea; headache.
2. Less Common Side Effects: Fever, joint pain, rash, or itching.
3. Serious Side Effects: Severe allergic reactions (such as difficulty breathing, swelling of the face or throat), severe diarrhea, or unusual bleeding/bruising.

Contraindications for Penicillin G Benzathine

A contraindication is a specific situation or condition where a medication should not be used because it may be harmful. Before starting any new medication, it’s important to know if you have any conditions that make it unsafe. Below are the contraindications for Penicillin G benzathine:

1. Allergy to Penicillin or Beta-lactam Antibiotics: If you have a known allergy to penicillin or other beta-lactam antibiotics (such as cephalosporins), you should not take Penicillin G benzathine. Allergic reactions can range from mild rashes to severe, life-threatening anaphylaxis.
2. Severe Renal Impairment: Patients with severe kidney issues may not be able to properly clear the drug from their system, leading to toxic levels. Your healthcare provider may recommend an alternative treatment if you have significant kidney problems.
3. History of Severe Hypersensitivity Reactions: If you have experienced severe hypersensitivity reactions (such as Stevens-Johnson syndrome) to any medications, you should avoid Penicillin G benzathine as it may trigger a similar response.

Drug Interactions with Penicillin G Benzathine

Penicillin G benzathine may interact with other medications, potentially reducing its effectiveness or increasing the risk of side effects. Always inform your healthcare provider about all the medications you are taking, including over-the-counter drugs and supplements. Below are some known drug interactions:

1. Probenecid (Benemid): Probenecid can increase the levels of Penicillin G benzathine in your blood, potentially leading to toxicity. This medication is sometimes used intentionally to prolong the effect of penicillin, but it should only be done under medical supervision.
2. Tetracyclines (e.g., Doxycycline): Tetracyclines (such as Doxycycline) may reduce the effectiveness of Penicillin G benzathine by interfering with its ability to kill bacteria. These medications should not be used together unless specifically directed by your healthcare provider.
3. Oral Contraceptives (Birth Control Pills): Penicillin G benzathine may reduce the effectiveness of hormonal birth control pills, increasing the risk of unintended pregnancy. Consider using an additional form of contraception while taking this antibiotic.

Penicillin G Benzathine in Pregnancy

Is it safe to take Penicillin G benzathine when pregnant?

Yes, Penicillin G benzathine is generally considered safe during pregnancy. It is classified as an FDA Pregnancy Category B medication, meaning that animal studies have not shown harm to the fetus, although there are no well-controlled studies in pregnant women. However, it is essential to consult your healthcare provider before taking any medication during pregnancy. If treatment is necessary, our telemedicine providers can help you determine the safest course of action for both you and your baby.

Penicillin G Benzathine While Breastfeeding

Is it safe to take Penicillin G benzathine while breastfeeding?

Yes, Penicillin G benzathine is generally safe to use while breastfeeding. Although small amounts of the medication may pass into breast milk, it is not known to cause harm to nursing infants. However, if your baby shows signs of an allergic reaction—such as a rash, diarrhea, or unusual fussiness—contact your healthcare provider immediately. If you have any concerns about taking this medication while breastfeeding, our telemedicine providers are available to discuss your options and address any questions you may have.

Estimated Cost of Penicillin G Benzathine

The cost of Penicillin G benzathine can vary depending on the pharmacy and your location. Without insurance, using a GoodRX coupon, the estimated cost for a single dose (the typical method of administration) ranges from $20 to $50. Since Penicillin G benzathine is often given as a one-time injection, a 30-day supply is not usually applicable. However, if multiple doses are required, your healthcare provider can help you plan for the associated costs and explore any available financial assistance options.

Possible Alternatives to Penicillin G Benzathine

If Penicillin G benzathine is not suitable for you, or if you are considering alternative treatments, there are other options available depending on the condition being treated. Always consult your healthcare provider before making any changes to your treatment plan. Our telemedicine providers can assist you in exploring these alternatives and finding the best option for your specific needs.

Rheumatic Fever

For patients allergic to penicillin, alternatives include antibiotics such as erythromycin or azithromycin. Long-term prevention may also involve lifestyle adjustments, including regular medical follow-ups and managing any underlying heart conditions.

Syphilis

For patients with a penicillin allergy, doxycycline or tetracycline may be used as alternatives. However, Penicillin G benzathine remains the most effective treatment, especially during pregnancy, where it is the preferred option.

Streptococcal Pharyngitis (Strep Throat)

Alternatives for treating strep throat include amoxicillin or cephalexin for those who can tolerate other beta-lactam antibiotics. For patients allergic to penicillin, azithromycin may be used as an alternative.

Bacterial Endocarditis

Depending on the specific bacteria involved, alternatives may include vancomycin or gentamicin. Preventive measures, such as maintaining good oral hygiene, are also important in reducing the risk of bacterial endocarditis.

Skin Infections

Alternatives for treating skin infections may include cephalexin or clindamycin, depending on the bacteria causing the infection. Proper wound care and hygiene are also essential in managing and preventing skin infections.

Pneumonia

Depending on the cause of the pneumonia, alternatives may include azithromycin or levofloxacin. Preventive measures, such as vaccination and smoking cessation, are also important in reducing the risk of pneumonia.

Osteomyelitis

For osteomyelitis, alternatives may include clindamycin or vancomycin, depending on the bacteria involved. Long-term management of osteomyelitis may also require surgery and physical therapy to ensure full recovery.

Meningitis

Alternatives for treating bacterial meningitis may include ceftriaxone or vancomycin, depending on the specific bacteria causing the infection. Vaccination is a key preventive measure against certain types of bacterial meningitis.

Anthrax

For anthrax, alternatives may include ciprofloxacin or doxycycline. In cases of inhalational anthrax, immediate medical treatment is critical and may involve a combination of antibiotics to ensure effective treatment.

Diphtheria

For diphtheria, erythromycin may be used as an alternative treatment. However, vaccination remains the most effective preventive measure against diphtheria and is strongly recommended.

Recent Updates on Penicillin G Benzathine Research

Recent studies have focused on improving the delivery and effectiveness of Penicillin G benzathine, particularly in the treatment of syphilis and rheumatic fever. Ongoing research is exploring long-acting formulations that could reduce the frequency of injections, making it more convenient for patients who require long-term prophylaxis. Additionally, researchers are investigating the use of Penicillin G benzathine in combination with other antibiotics to treat resistant bacterial infections. Always consult your healthcare provider for the latest treatment recommendations. Our telemedicine providers are available to discuss any new research that may impact your treatment plan and help you make informed decisions about your care.

James Kingsley

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