[penicillin photo]
KEY POINTS
- Penicillin is a beta-lactam antibiotic that works by inhibiting the bacterial cell wall in susceptible organisms
- Penicillin was originally discovered in 1928 by Alexander Fleming, but was not employed in clinical practice on a large scale until World War II in the 1940s
- Available for oral, intravenous and intramuscular administration
- Widely considered the drug of choice for various Gram positive anaerobes (e.g., Clostridium perfringens), beta-hemolytic Streptococci (e.g., Streptococcus pyogenes & Streptococcus agalactiae) and syphilis (Treponema pallidum)
- Beware penicillin resistance in alpha-hemolytic Streptococci (e.g., Streptococcus pneumoniae & Viridans group Streptococci)
- Frequent dosing is common, except with the intramuscular formulation
- Adjust doses for renal function
- Failing to adjust doses for renal function may increase the risk for seizure
- Aqueous penicillin G can be given via a continuous infusion over 20-24 hours
- Adjust doses for renal function
- Beware nausea, vomiting, diarrhea, seizure, electrolyte abnormalities and hypersensitivity reactions
- Prolonged use (especially >28 days) has been associated with neutropenia, anemia and thrombocytopenia
- Inaccurate penicillin allergy labels are extremely common and penicillin skin testing may be an option to evaluate a questionable penicillin allergy label
RESOURCES
- Penicillin G Potassium For Injection Package Insert
- Penicillin G Benzathine Injectable Suspension Package Insert
- Penicillin G Procaine Injectable Package Insert
- Penicillin V Potassium Oral Tablet & Suspension Package Insert
- Penicillins Review – Mayo Clinic Proceedings (1999)
- IDSA Practice Guidelines
- 2015 CDC STD Guideline
- Infective Endocarditis Guidelines – European Society of Cardiology (2015)