# Situation: A 70-year-old retired factory worker is admitted to the medical ward with pneumonia and is started on intravenous gentamicin. His daughter says his hearing has worsened over several years, especially in noisy rooms. On day 5 of gentamicin the nurse reviews his data. Per unit protocol, the target trough level is below 1 mg/L. Trough: day 2, 0.6 mg/L; day 5, 0.8 mg/L Creatinine: day 1, 0.9 mg/dL (80 µmol/L); day 5, 1.0 mg/dL (88 µmol/L) He now reports ringing in both ears and a sense of fullness, and he feels unsteady when he walks. Which evaluation of his therapy is correct?

> source: MyMerci (mymerci.kr)  
> url: https://mymerci.kr/pages/nclex_q.php?qn_id=630545  
> language: ko  
> subject: Nursing Practice IV — Care of Clients with Problems in Nutrition and Gastrointestinal, Metabolism and Endocrine, Perception and Coordination

## 문제

Situation: A 70-year-old retired factory worker is admitted to the medical ward with pneumonia and is started on intravenous gentamicin. His daughter says his hearing has worsened over several years, especially in noisy rooms.

On day 5 of gentamicin the nurse reviews his data. Per unit protocol, the target trough level is below 1 mg/L.
Trough: day 2, 0.6 mg/L; day 5, 0.8 mg/L
Creatinine: day 1, 0.9 mg/dL (80 µmol/L); day 5, 1.0 mg/dL (88 µmol/L)
He now reports ringing in both ears and a sense of fullness, and he feels unsteady when he walks. Which evaluation of his therapy is correct?

## 보기

1. Possible drug toxicity; report it before the next dose **✔ 정답**
2. No toxicity, since the trough level is within target
3. No toxicity, since kidney function is unchanged
4. Age-related hearing loss explains the new ear symptoms

**정답: 1**

## 해설

Aminoglycosides such as gentamicin can damage the cochlea and vestibular system, sometimes permanently, and toxicity can occur even when trough levels are in range. The nurse asks daily about tinnitus, fullness, hearing change and dizziness and reports new symptoms before the next dose so the prescriber can review the drug.

## 심화 해설

Symptoms outweigh an in-range level
On day 5 of gentamicin, the client reports ringing in both ears (tinnitus), a sense of fullness, and unsteadiness when he walks. His trough levels (0.6 and 0.8 mg/L) are below the target of 1 mg/L, and his creatinine has barely changed (0.9 to 1.0 mg/dL). It is tempting to decide that the drug is safe. Aminoglycosides can damage the cochlea and the vestibular system even when trough levels are within range, so new ear symptoms are treated as possible toxicity. The nurse reports them before the next dose so the prescriber can review the drug.

How aminoglycoside ototoxicity happens
Gentamicin and other aminoglycosides accumulate in the fluids of the inner ear and damage the hair cells of the cochlea, which sense sound, and of the vestibular organs, which sense balance and head movement. Cochlear damage causes tinnitus, fullness, and high-frequency hearing loss; vestibular damage causes dizziness, imbalance, and unsteady walking. Gentamicin is particularly vestibulotoxic. The damage can be permanent, and risk rises with older age, longer courses, prior hearing loss, and other ototoxic drugs such as loop diuretics. This client is 70, already has hearing loss, and is in a high-risk group.

| Data | Value | Interpretation |
| --- | --- | --- |
| Trough | 0.6 and 0.8 mg/L (target below 1) | In range, but does not exclude toxicity |
| Creatinine | 0.9 to 1.0 mg/dL | Stable kidney function |
| Tinnitus, fullness, unsteadiness | New on day 5 | Possible cochlear and vestibular toxicity |

Why the other evaluations are wrong
Saying there is no toxicity because the trough is in range relies on a number while ignoring symptoms. Saying there is no toxicity because kidney function is unchanged confuses two adverse effects: stable kidneys lower the risk of accumulation but do not rule out ototoxicity. Blaming age-related hearing loss does not fit, because presbycusis develops slowly over years and does not cause sudden tinnitus with imbalance.

Nursing monitoring on aminoglycosides
The nurse asks every day about tinnitus, fullness, hearing change, and dizziness, observes gait, monitors creatinine, urine output, and levels, and avoids combining with other ototoxic or nephrotoxic drugs when possible. Fall precautions are started for unsteadiness.

Exam takeaway
Watch out A therapeutic drug level does not make an aminoglycoside safe. New tinnitus, fullness, or dizziness is reported before the next dose.

## 임상 시나리오

Gentamicin and the Inner EarOtotoxicity despite in-range levels
Aminoglycosides can damage cochlear and vestibular hair cells, sometimes permanently, even when trough levels are in range.

New tinnitus, ear fullness, and unsteadiness on day 5 suggest toxicity. Report them before the next dose.

Ask daily about hearing, ringing, fullness, and dizziness, observe gait, and monitor kidney function and levels.

CautionOlder age, existing hearing loss, and loop diuretics raise the risk. Start fall precautions for unsteadiness.

## 핵심 개념

- **Ototoxicity** — Drug damage to the inner ear causing hearing loss, tinnitus, or balance problems.
- **Aminoglycoside** — An antibiotic class, including gentamicin, that can damage the kidneys and inner ear.
- **Tinnitus** — Ringing, buzzing, or other noise heard in the ears without an outside source.
- **Vestibular toxicity** — Drug damage to the balance organs of the inner ear, causing dizziness and unsteady walking.

## 같은 주제 문제

- [Situation: A 68-year-old man is on the medical ward on day 4 after an ischemic stroke in t…](https://mymerci.kr/pages/nclex_q.php?qn_id=630316)
- [Situation: A 68-year-old man is on the medical ward on day 4 after an ischemic stroke in t…](https://mymerci.kr/pages/nclex_q.php?qn_id=630317)
- [Situation: A 68-year-old man is on the medical ward on day 4 after an ischemic stroke in t…](https://mymerci.kr/pages/nclex_q.php?qn_id=630318)
- [Situation: A 68-year-old man is on the medical ward on day 4 after an ischemic stroke in t…](https://mymerci.kr/pages/nclex_q.php?qn_id=630319)
- [Situation: A 72-year-old woman with Parkinson disease for 9 years is admitted to the medic…](https://mymerci.kr/pages/nclex_q.php?qn_id=630320)
- [Situation: A 72-year-old woman with Parkinson disease for 9 years is admitted to the medic…](https://mymerci.kr/pages/nclex_q.php?qn_id=630321)
- [Situation: A 72-year-old woman with Parkinson disease for 9 years is admitted to the medic…](https://mymerci.kr/pages/nclex_q.php?qn_id=630322)
- [Situation: A 72-year-old woman with Parkinson disease for 9 years is admitted to the medic…](https://mymerci.kr/pages/nclex_q.php?qn_id=630323)

---

More free questions: [기출문제](https://mymerci.kr/)

_학습 참고용입니다. 실제 임상은 최신 지침과 소속 기관 프로토콜을 따르세요._