penicillin G procaine /penicillin G benzathine

Action and Spectrum

Actions and Spectrum: 

penicillin G benzathine / penicillin G procaine are both types of penicillin antibiotics that are used to treat bacterial infections. They have similar spectra of activity, but differ in their pharmacokinetics and clinical uses. 

penicillin G benzathine is a long-acting penicillin that is administered by intramuscular injection. It is generally used to treat a variety of bacterial infections, including streptococcal infections, syphilis, and diphtheria. penicillin G benzathine has a relatively narrow spectrum of activity, targeting primarily gram-positive bacteria. 

penicillin G procaine, on the other hand, is a shorter-acting penicillin that is also administered by intramuscular injection. It is generally used to treat a wider range of bacterial infections, including pneumonia, endocarditis, and meningitis. penicillin G procaine has a broader spectrum of activity than penicillin G benzathine, targeting both gram-positive and gram-negative bacteria. 

Both penicillin G benzathine / penicillin G procaine work by inhibiting synthesis of bacterial cell walls, which eventually leads to bacterial death. However, they differ in their pharmacokinetics, with penicillin G benzathine having a longer half-life and slower absorption rate than penicillin G procaine. This means that penicillin G benzathine is more suitable for treating long-term infections that require sustained antibiotic therapy, while penicillin G procaine is better suited for acute infections that require rapid resolution. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Skin rashes like exfoliative dermatitis and maculopapular eruptions. 

Pseudomembranous colitis 

Jarisch-Herxheimer reaction 

Arthralgia 

Fever 

Chills 

Edema 

prostration 

Black Box Warning

Black Box Warning: 

penicillin G benzathine / penicillin G procaine both have black box warnings, which are the strongest type of warning issued by the US Food and Drug Administration (FDA). The black box warning for penicillin G benzathine pertains to the potential for anaphylaxis, a severe and potentially life-threatening allergic reaction.

The warning states that patients should be monitored for at least 30 minutes after administration of the drug, and that immediate treatment should be provided in the event of an allergic reaction. 

The black box warning for penicillin G procaine pertains to the potential for neurotoxicity, which can cause seizures or other neurological symptoms. The warning states that the drug used with caution in patients with a prior history of seizures, and that the dosage should be adjusted in patients with impaired renal function. 

Contraindication / Caution

Contraindication/Caution: 

Contraindication 

penicillin G benzathine / penicillin G procaine are contraindicated in patients with a known hypersensitivity to penicillin or any other beta-lactam antibiotic. Other contraindications for these drugs include: 

• History of severe or immediate allergic reactions to penicillin or other beta-lactam antibiotics 
• History of severe liver disease or renal impairment 
• Active infection with a viral illness, such as infectious mononucleosis, as the use of penicillin antibiotics in such cases may lead to a rash or other allergic reactions 
• Use of tetracycline antibiotics, as they may interfere with the effectiveness of penicillin antibiotics. 

Caution 

• Renal Impairment: Patients with impaired renal function may require dosage adjustment or a longer dosing interval, as penicillin antibiotics are primarily excreted by the kidneys. 
• History of Allergic Reactions: Patients with a prior history of allergic reactions to penicillin or beta-lactam antibiotics may be at increased risk of an allergic reaction to penicillin G benzathine or penicillin G procaine. 
• Bleeding Disorders: Penicillin antibiotics may interfere with platelet function and increase the risk of bleeding in patients with bleeding disorders. 
• Pregnancy and Breastfeeding: Penicillin antibiotics are generally considered safe for use in pregnancy and breastfeeding but caution is needed. 
• Concurrent Use with Other Medications: Penicillin antibiotics may interact with other medications, such as oral contraceptives, anticoagulants, and probenecid, which may require dosage adjustment or careful monitoring. 

Pregnancy / Lactation

Pregnancy consideration:  

US FDA pregnancy category: Not assigned. 

Lactation:   

Excreted into human milk is known. 

Pregnancy category: 

• Category A: well-controlled and Satisfactory studies do not show risk to the fetus in the first/later trimester.        
• Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women        
• Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.       
• Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.        
• Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.        
• Category N: There is no data available for the drug under this category 

Pharmacology

Pharmacology: 

penicillin G benzathine / penicillin G procaine are both penicillin antibiotics that belong to the beta-lactam class of antibiotics. These drugs work by inhibiting the synthesis of bacterial cell walls, which are necessary for the survival of bacteria. Specifically, penicillin antibiotics bind to and inhibit the enzymes involved in the final stages of bacterial cell wall synthesis, leading to cell death and bacterial lysis. 

Pharmacodynamics: 

Mechanism of action: The drug works by disrupting synthesis of cell wall mucopeptides during the active multiplication, which ultimately leads to its bactericidal activity against susceptible microorganisms. 

Pharmacokinetics: 

Absorption:  

After intramuscular injection, both penicillin G benzathine / penicillin G procaine are slowly absorbed into the bloodstream. penicillin G benzathine is absorbed more slowly than penicillin G procaine due to its formulation with benzathine, which acts as a slow-release carrier for the drug. 

Distribution: 

penicillin antibiotics are distributed throughout the body and penetrate well into most tissues and body fluids, including cerebrospinal fluid. Both penicillin G benzathine / penicillin G procaine have a long duration of action due to their slow release from the injection site and their ability to bind to tissues and form a depot. 

Metabolism:  

Penicillin antibiotics are not extensively metabolized in the body. 

Elimination:  

Penicillin antibiotics are primarily eliminated from the body by renal excretion. The elimination half-life of penicillin G benzathine is longer than that of penicillin G procaine due to its slow release from the injection site. 

Adminstartion

Administration: 

Intramuscular administration 

penicillin G benzathine / penicillin G procaine are both administered by intramuscular injection, which should be performed by a healthcare provider. The specific dosage and dosing interval will depend on the patient’s age, weight, and the specific condition being treated. 

When administering penicillin G benzathine, it is important to use the correct injection technique to ensure that the drug is properly absorbed and distributed throughout the body. The injection should be given slowly and deeply into the muscle, and the patient should remain in a supine position for 10 minutes after injection to minimize the risk of adverse reactions. 

Penicillin G procaine should also be administered by intramuscular injection, using the correct injection technique. The injection site should be chosen carefully to avoid major nerves or blood vessels. The drug should be injected slowly and deeply into the muscle, and the patient should be monitored for at least 30 minutes after injection to detect any immediate adverse reactions. 

It is important to adhere to the prescribed dosage and dosing interval when administering penicillin antibiotics, as under- or overdosing can lead to treatment failure or adverse reactions.  

If a dose is missed, it is recommended to take it as soon as possible. However, if the next scheduled dose is missed, it should be skipped and the following dose should be taken at the appropriate time. It is important to avoid taking a double dose of the medication to compensate for the missed dose.

Patient Information Leaflet

Patient information leaflet 

Generic Name: penicillin G benzathine / penicillin G procaine 

Why do we use penicillin G benzathine / penicillin G procaine? 

penicillin G benzathine / penicillin G procaine are both antibiotics that are generally used to treat bacterial infections caused by susceptible strains of bacteria. These drugs are particularly effective against infections caused by Streptococcus species, including strep throat, scarlet fever, and rheumatic fever. Other uses of these drugs include: 

• Syphilis: Penicillin antibiotics are the preferred treatment for syphilis, and penicillin G benzathine is often used as a single injection for the treatment of early syphilis. 
• Gonorrhea: Penicillin antibiotics were once the standard treatment for gonorrhea, but resistant strains have emerged, and other antibiotics are now typically used. 
• Actinomycosis: Penicillin antibiotics are effective against Actinomyces species, which can cause infections such as actinomycosis. 
• Other bacterial infections: Penicillin antibiotics may be used to treat a vast range of bacterial infections, including endocarditis, meningitis, pneumonia, and skin and soft tissue infections.