Stridor, wheezing, throat tightness, facial swelling, or hypotension signal anaphylaxis - stop the drug and get help immediately.
Before you read
Test yourself first: 3 questions
Question 1 of 3
A nurse is preparing to hang IV piperacillin-tazobactam for a client. The client reports a previous mild rash with amoxicillin. What is the most appropriate nursing action?
Answer: A. Both amoxicillin and piperacillin are penicillins, so a prior penicillin reaction raises cross-sensitivity concern. The nurse should hold the drug and notify the prescriber to clarify the order before administering. Administering it anyway, simply documenting, or slowing the rate does not address the potential cross-allergy.
Question 2 of 3
A nurse is teaching a young woman who has been prescribed amoxicillin about an important interaction. Which teaching point should the nurse emphasize?
Answer: A. Penicillins, including amoxicillin, may reduce the effectiveness of oral contraceptives. A woman of childbearing age should be advised to use an additional, nonhormonal method of contraception during therapy. The drug does not require avoiding sunlight, taking on a completely empty stomach only, or restricting protein.
Question 3 of 3
A nurse is administering an oral antibiotic that must be taken on an empty stomach for proper absorption. Which medication requires this instruction?
Answer: A. Penicillin V and other penicillins (and tetracyclines) are best absorbed on an empty stomach, taken about 1 hour before or 2 hours after meals. Many other drugs are taken with food to reduce GI upset, but the classic teaching for optimal absorption applies to oral penicillin. Amoxicillin can be taken with or without food; metronidazole and nitrofurantoin are taken with food to reduce GI distress.
Keep the streak going with more questions like these, each with a full rationale.
What is penicillins?
They are among the most common causes of drug allergy and anaphylaxis. The key safety principle is always screening for penicillin and cephalosporin allergy before giving.
Key points to remember
- Penicillins are bactericidal and work by inhibiting bacterial cell wall synthesis.
- Cross-sensitivity exists with cephalosporins, so a penicillin allergy raises caution with cephalosporins.
- Take oral penicillins on an empty stomach (except amoxicillin) for best absorption.
- A maculopapular rash is common with ampicillin, especially in patients with mononucleosis, and is not always a true allergy.
- Penicillins can reduce the effectiveness of oral contraceptives.
- Probenecid raises and prolongs penicillin blood levels by slowing renal excretion.
Nursing priorities
- Ask about and document any prior penicillin or cephalosporin allergy before the first dose.
- Keep epinephrine and emergency equipment available, especially with IV or IM doses.
- Observe the patient for at least 30 minutes after a parenteral dose for allergic reaction.
- Give the full prescribed course and emphasize completing all doses to the patient.
- Monitor renal function and check that the dose is adjusted for kidney impairment.
Labs & values
Patient teaching
- Finish the entire prescription even if you feel better.
- Use a backup birth control method while on the antibiotic and for the rest of that cycle.
- Report any rash, hives, swelling, or trouble breathing right away.
- Take most oral penicillins on an empty stomach with a full glass of water.
Red flags: report now
- Stridor, wheezing, throat tightness, facial swelling, or hypotension signal anaphylaxis - stop the drug and get help immediately.
- Never give a penicillin to a patient with a documented penicillin anaphylaxis history.
- Severe or bloody diarrhea may indicate C. difficile colitis and must be reported.
References
Clinical references for this topic
