# A 6-year-old (20 kg) receives a first dose of IV ampicillin in the ED. Within 5 minutes the child develops urticaria, lip and tongue swelling, audible wheezing, BP 70/40, HR 150. Which is the first priority intervention?

> source: MyMerci (mymerci.kr)  
> url: https://mymerci.kr/pages/nclex_q.php?qn_id=375217&lang=en  
> language: en  
> subject: Adverse Effects/Contraindications/Interactions  
> category: PA

## Question

A 6-year-old (20 kg) receives a first dose of IV ampicillin in the ED. Within 5 minutes the child develops urticaria, lip and tongue swelling, audible wheezing, BP 70/40, HR 150. Which is the first priority intervention?

## Option

1. Reduce the ampicillin infusion to a rate of 10 mg per minute over 1 hour, administer diphenhydramine 1 mg/kg IV, provide high-flow oxygen via non-rebreather mask, place the child in a semi-Fowler's position, give a 10 mL/kg normal saline IV bolus, reassess in 15 minutes; if symptoms improve, continue the infusion and premedicate with prednisolone 1 mg/kg PO for future doses.
2. Stop the antibiotic, call rapid response, give epinephrine 0.01 mg/kg (0.2 mg = 0.2 mL of 1 mg/mL) IM into the anterolateral thigh, support airway with high-flow oxygen, place supine with legs elevated, give IV NS bolus 20 mL/kg, repeat epinephrine in 5 to 15 minutes if needed, and prepare H1, H2, and corticosteroid as adjuncts. **✔ Correct answer**
3. Administer a 20 mL/kg normal saline IV bolus, tilt the bed to Trendelenburg, apply high-flow oxygen, take vital signs, and notify the provider to prepare diphenhydramine 1 mg/kg IV and famotidine 0.25 mg/kg IV; reassess in 1 hour, and if symptoms do not improve, give epinephrine 0.01 mg/kg IM.
4. Give diphenhydramine 1 mg/kg orally, apply calamine lotion to urticaria, have the child sit upright with legs dependent, provide reassurance, and observe for 30 minutes; if wheezing or swelling persist, call rapid response and then administer epinephrine 0.01 mg/kg IM into the thigh.

**Correct answer: 2**

## Explanation

This is anaphylaxis — the IgE-mediated, life-threatening hypersensitivity that follows minutes after an antigen exposure with multisystem features (skin, respiratory, cardiovascular, GI). The first-line drug is intramuscular epinephrine; delay and use of antihistamines or steroids alone are common errors that increase mortality. Pediatric dose: 0.01 mg/kg of 1 mg/mL (1:1000) IM into the anterolateral thigh, max single dose 0.3 mg pre-pubertal or 0.5 mg adult, repeat every 5 to 15 minutes as needed. Concurrent actions: stop the offending antibiotic, call rapid response or code, support airway with oxygen and prepare for intubation if airway compromise progresses, place supine with legs elevated unless respiratory distress favors upright, IV access for normal saline bolus 20 mL/kg as needed for hypotension; nebulized albuterol for bronchospasm; H1 (diphenhydramine) and H2 (famotidine) antihistamines and corticosteroid (methylprednisolone) as adjuncts only after epinephrine. Monitor for biphasic reaction up to 8 to 12 hours. Document, prescribe an epinephrine auto-injector at discharge with teaching, and arrange allergy follow-up. Diphenhydramine alone, slowing the antibiotic, or fluid alone are unsafe and miss the priority of epinephrine.

## In-depth explanation

Anaphylaxis = IM epinephrine first. Antihistamines and steroids are adjuncts, not substitutes. Anterolateral thigh is the preferred site.

## Related questions

- [A nurse is reviewing the morning lab results for an adult client receiving warfarin for at…](https://mymerci.kr/pages/nclex_q.php?qn_id=360515&lang=en)
- [A client is admitted to the emergency department after ingesting an unknown amount of acet…](https://mymerci.kr/pages/nclex_q.php?qn_id=362720&lang=en)
- [A client with chronic heart failure is prescribed metoprolol 25 mg orally twice daily. Bef…](https://mymerci.kr/pages/nclex_q.php?qn_id=362756&lang=en)
- [A 28-year-old client with type 1 diabetes receives regular insulin 6 units and NPH insulin…](https://mymerci.kr/pages/nclex_q.php?qn_id=362792&lang=en)
- [A client receives IV vancomycin 1 g every 12 hours for MRSA bacteremia. Before the next do…](https://mymerci.kr/pages/nclex_q.php?qn_id=362833&lang=en)
- [A client with bipolar disorder has been taking lithium carbonate 600 mg orally three times…](https://mymerci.kr/pages/nclex_q.php?qn_id=362894&lang=en)
- [An 80-year-old male with heart failure is prescribed digoxin 0.125 mg daily. During mornin…](https://mymerci.kr/pages/nclex_q.php?qn_id=372686&lang=en)
- [A 38-year-old female with rheumatoid arthritis is being discharged with a new prescription…](https://mymerci.kr/pages/nclex_q.php?qn_id=372687&lang=en)

## Read in another language

- [en](https://mymerci.kr/pages/nclex_q.php?qn_id=375217&lang=en)
- [ko](https://mymerci.kr/pages/nclex_q.php?qn_id=375217&lang=ko)
- [ja](https://mymerci.kr/pages/nclex_q.php?qn_id=375217&lang=ja)
- [zh-TW](https://mymerci.kr/pages/nclex_q.php?qn_id=375217&lang=zh-tw)
- [vi](https://mymerci.kr/pages/nclex_q.php?qn_id=375217&lang=vi)

---

More free questions: [NCLEX-RN Practice](https://mymerci.kr/pages/nclex_bank.php?lang=en)

_For study reference only. Always follow current clinical guidelines and your institution’s protocols._