Penicillins are one of the most popular class of antibiotics. They are commonly used today, and interestingly, were actually one of the first antibiotics ever discovered by scientists.
As a nursing student or healthcare professional, understanding how penicillins work, their uses, and key nursing considerations is essential. This quick review will walk you through the mechanism of action, common examples, indications, and important side effects to remember.
What Are Penicillins?
Penicillins are antibiotics that share the common suffix “-cillin”. Popular examples include:
- Penicillin
- Amoxicillin
What Do Penicillins Treat?
Penicillins primarily target gram-positive bacteria. A simple way to remember this: P for Penicillin = Positive.
However, some penicillins (like amoxicillin) have a broader spectrum, meaning they can also target certain gram-negative bacteria.
Common infections treated with penicillins:
- Strep throat
- Syphilis
- Ear infections (otitis media)
- Respiratory and skin infections
Lecture on Penicillin Antibiotics
Mechanism of Action of Penicillin
Penicillins work by inhibiting bacterial cell wall synthesis. This action is bactericidal, meaning it kills bacteria rather than just slowing their growth.
Key Nursing Considerations: The “PCNS” Acronym
A helpful way to remember the major points for penicillins is the acronym PCNS:
P – Penicillin allergy is common
- Penicillins are the most common antibiotic allergy.
- Always ask about allergy history.
- Monitor for rash, hives, or serious reactions like anaphylaxis.
C – Cross-sensitivity with cephalosporins
- Patients allergic to penicillin may also react to cephalosporins.
- Use caution and verify with the provider before administering.
N – Nausea and GI upset
- Penicillins can cause stomach upset.
- Patients may take them with food to ease symptoms, but note that some penicillins absorb better on an empty stomach.
S – Superinfections
- Prolonged use can lead to C. difficile infection (watery, foul-smelling diarrhea).
- Other superinfections: oral thrush and vaginal yeast infections.
You may be interested in: Penicillin Antibiotics NCLEX-Style Questions
References:
U.S. Food and Drug Administration. (2016, July). Penicillin G Potassium Injection, USP [Labeling]. https://www.accessdata.fda.gov/drugsatfda_docs/label/2016/050638s019lbl.pdf
U.S. National Library of Medicine. (2016, February 15). Penicillin G (Potassium, Sodium) Injection. MedlinePlus. https://medlineplus.gov/druginfo/meds/a685013.html