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Benzathine benzylpenicillin

Uses|Precautions & Warnings|Side Effects|Interactions|Dosage

Uses

What is benzathine benzylpenicillin used for?

Benzathine benzylpenicillin is an antibiotic used to treat a variety of infections. It is a long-acting penicillin antibiotic that works by binding to the bacterial cell wall causing it to rupture, killing the bacteria.

Benzathine benzylpenicillin is mainly indicated to treat or prevent:

  • Syphilis
  • Streptococcal pharyngitis
  • Treponemal infections
  • Congenital syphilis
  • Rheumatic fever (prophylaxis)

How should I take benzathine benzylpenicillin?

Benzathine benzylpenicillin is available as a powder for injection. It should be reconstituted with a suitable diluent before injection. Only a licensed health professional should administer this drug.

How do I store benzathine benzylpenicillin?

Benzathine benzylpenicillin should be stored in the refrigerator (2-8°C). Do not freeze. For safety, keep out of the reach of children and pets.

Always check the label before using this product. Do not use if the printed expiration date has passed, the product seal has been broken, or the product has changed in color, odor, or consistency.

Do not dispose of this product by pouring it down the drain, toilet, or into the environment. Ask your pharmacist regarding the proper way and location of disposal.

Precautions & Warnings

What should I know before using benzathine benzylpenicillin?

Before using this medication, inform your doctor if:

  • You have ever had an allergic reaction to benzathine benzylpenicillin or other penicillins.
  • You have a history of allergy to other medications, food, or other substances.
  • You are taking other medications.
  • You have underlying health conditions.

Is it safe during pregnancy or breastfeeding?

This drug is a pregnancy category B drug. There are no adequate and well-controlled studies using cefazolin in pregnant women. However, animal studies show no risk to the fetus. This drug should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus, as determined by your doctor.

This drug is excreted in breast milk. This drug should be used while breastfeeding only if the potential benefit justifies the potential risk to the child, as determined by your doctor.

Side Effects

What side effects can occur when using benzathine benzylpenicillin?

All drugs have the potential to elicit side effects even with normal use. Many side effects are dose-related and will resolve when it is adjusted or at the end of therapy.

Potential side effects while using benzathine benzylpenicillin include:

  • Nausea, vomiting
  • Diarrhea
  • Mild allergic reaction
  • Serum sickness-like reactions
  • Injection site reactions
  • Fever
  • Joint pain
  • Anemia

Rare, serious adverse reactions:

  • Anaphylactic reaction
  • Antibiotic-associated pseudomembranous colitis

You may experience some, none, or other side effects not mentioned above. If you experience serious adverse reactions, you must stop taking the drug immediately. If you have any concerns about a side effect or it becomes bothersome, consult your doctor or pharmacist.

Interactions

What drugs may interact with benzathine benzylpenicillin?

Benzathine benzylpenicillin may interact with other medications. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist.

Known drugs and associated interactions with benzathine benzylpenicillin include:

  • Tetracyclines
    • Decreased therapeutic effect of benzathine benzylpenicillin
  • BCG and typhoid vaccines
    • Decreased therapeutic effect of these vaccines
  • Probenecid
    • Decreased clearance of benzathine benzylpenicillin

If you experience an adverse drug interaction, stop taking this drug and continue taking your other medication. Inform your doctor immediately to reevaluate your treatment plan. Your dose may need to be adjusted, substituted with another drug, or discontinue using the drug.

Does food or alcohol interact with benzathine benzylpenicillin?

This drug has no notable interactions with food or alcohol.

Contact your doctor or pharmacist if you have any concerns regarding food-drug interactions.

What health conditions may interact with benzathine benzylpenicillin?

Benzathine benzylpenicillin should be taken with caution if you have any of the following conditions or risk factors:

  • History of hypersensitivity to penicillins
  • Renal impairment
  • GI disease
    • Colitis
    • Clostridium difficile-associated diarrhea
  • Seizure disorder

Inform your doctor or pharmacist if you have any concerns regarding specific health conditions.

Dosage

The information provided is not a substitute for any medical advice. You should ALWAYS consult your doctor or pharmacist before using benzathine benzylpenicillin.

What is the dose of benzathine benzylpenicillin for an adult?

All doses are to be given via intramuscular (IM) injection.

To treat syphilis (primary, secondary and latent)

  • Administer 1.8 g (2.4 MIU) as a single dose.
  • Late (tertiary and neurosyphilis): administer 1.8 g (2.4 MIU) once a week for 3 weeks.

To treat streptococcal pharyngitis

  • Administer 900 mg (1.2 MIU) as a single dose.

To treat treponemal infections

  • Administer 900 mg (1.2 MIU) as a single dose.
As primary prophylaxis of rheumatic fever
  • Administer 900 mg (1.2 MIU) as a single dose

To prevent recurrence of acute attack:

  • Administer 900 mg (1.2 MIU) once every 3 or 4 weeks or 450 mg (600,000 U) once every 2 weeks.

What is the dose of benzathine benzylpenicillin for a child?

All doses are to be given by intramuscular (IM) injection.

To treat streptococcal pharyngitis

  • Weight <27 kg: administer 225-450 mg (300,000-600,000 U) as a single dose.
  • Weight ≥27 kg: administer 675 mg (900,000 U) as a single dose.

To treat treponemal infections

  • Administer 450 mg (600,000 U) as a single dose.

To treat congenital syphilis

  • Ages <2 years: administer 37.5 mg/kg (50,000 U/kg) as a single dose.
  • Ages 2 to 12 years: adjust dosage based on adult dosage schedule.
As primary prophylaxis of rheumatic fever
  • Weight <27 kg: 225-450 mg (300,000-600,000 U) as a single dose.
  • Weight ≥27 kg: 675 mg (900,000 U) as a single dose.

Prevention of recurrence of acute attack:

  • Weight <27 kg: administer 450 mg (600,000 U) once every 3 or 4 weeks.
  • Weight: ≥27 kg: administer 900 mg (1.2 MIU) once every 3 or 4 weeks.

How is benzathine benzylpenicillin available?

This drug is available in the following brands, dosage forms, and strengths:

  • Zalpen powder for injection 1200000 U
  • Phil Pharmawealth/Karnataka Benzathine Benzylpenicillin powder for injection 1.2 MIU

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of this drug, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose. Avoid missing doses to prevent antibiotic resistance and treatment failure.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Sources

Benzathine benzylpenicillin, https://www.mims.com/philippines/drug/info/benzathine%20benzylpenicillin?mtype=generic, Accessed Aug 20, 2020

Benzathine benzylpenicillin, https://medicalguidelines.msf.org/viewport/EssDr/english/benzathine-benzylpenicillin-injectable-16682488.html, Accessed Aug 20, 2020

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Written by Stephanie Nicole Nera, RPh, PharmD Updated Aug 22, 2020
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