👤 By the CinnaRN Clinical Content Team🕐 Updated 2026-08-23🏷️ Pharmacological Therapies🔖 Free to read, print, and share
Also known as: gentamicin · Garamycin · aminoglycoside · gent levels
💡
Use this quick-reference guide to spot, treat, and prevent Gentamicin (peak and trough) on the NCLEX. Keep it handy during review and on exam day!
🩺
📒 The 1-minute cheat sheet
📌 Use
Aminoglycoside → serious G- infection
IV, narrow therapeutic window
🧪 Levels
Trough <2: draw BEFORE dose
Peak 5-10: 30 min AFTER
📌 Toxic
Nephrotoxic + ototoxic
Trough ↑ → toxicity risk
🚩 Report
Tinnitus, hearing loss, vertigo
↓urine, ↑creatinine
📚 Gentamicin (peak and trough) — full study notes
The cheat sheet above is your quick recall card. These notes go deeper — what it is, what to do first, what must be reported, and what to teach.
Gentamicin is an aminoglycoside antibiotic used IV for serious gram-negative infections, with a narrow therapeutic range requiring peak and trough monitoring. Its major toxicities are nephrotoxicity and irreversible ototoxicity. The key principle is drawing peaks and troughs correctly so the trough stays low enough to protect the kidneys and ears.
🔑
Key points
Understand these first
Gentamicin is a bactericidal aminoglycoside with a narrow therapeutic window requiring serum level monitoring.
The trough is drawn just before the next dose and the peak is drawn about 30 minutes after the infusion ends.
A high trough reflects drug accumulation and increases the risk of nephrotoxicity and ototoxicity.
Nephrotoxicity is usually reversible, but ototoxicity (hearing loss, tinnitus, vertigo) can be permanent.
Therapeutic trough is generally below 2 mcg/mL and therapeutic peak is roughly 5 to 10 mcg/mL for traditional dosing.
The risk increases when combined with other nephrotoxic drugs such as loop diuretics or vancomycin.
✅
Nursing priorities
What to do, in order
Draw the trough right before the next dose and the peak about 30 minutes after the infusion ends.
Hold the dose and notify the provider if the trough is elevated.
Monitor renal function, intake, and output throughout therapy.
Assess for ototoxicity by asking about tinnitus, hearing changes, and dizziness.
Ensure adequate hydration and avoid concurrent nephrotoxic drugs when possible.
🚩
Red flags — report now
Escalate immediately
An elevated trough must be reported before the next dose is given.
Tinnitus, hearing loss, or vertigo may indicate ototoxicity and must be reported promptly.
Decreased urine output or rising creatinine signals nephrotoxicity and must be reported.
🧪
Labs & values
Numbers to know
Gentamicin trough below 2 mcg/mL (drawn just before next dose)
Gentamicin peak 5-10 mcg/mL (drawn 30 minutes after infusion)
Serum creatinine 0.6-1.2 mg/dL (monitor for nephrotoxicity)
BUN 7-20 mg/dL
🗣️
Patient teaching
What patients must know
Report any ringing in the ears, hearing changes, or dizziness right away.
Drink plenty of fluids unless your provider restricts them.
Blood will be drawn at specific times to keep the drug at a safe level.
Report any decrease in your urination.
❓ Gentamicin (peak and trough): NCLEX FAQs
What are the priority nursing interventions for Gentamicin (peak and trough)?
Draw the trough right before the next dose and the peak about 30 minutes after the infusion ends. Hold the dose and notify the provider if the trough is elevated. Monitor renal function, intake, and output throughout therapy. Assess for ototoxicity by asking about tinnitus, hearing changes, and dizziness.
What are the warning signs of Gentamicin (peak and trough) a nurse must report?
An elevated trough must be reported before the next dose is given. Tinnitus, hearing loss, or vertigo may indicate ototoxicity and must be reported promptly. Decreased urine output or rising creatinine signals nephrotoxicity and must be reported.
What do I need to know about Gentamicin (peak and trough) for the NCLEX?
Gentamicin is a bactericidal aminoglycoside with a narrow therapeutic window requiring serum level monitoring. The trough is drawn just before the next dose and the peak is drawn about 30 minutes after the infusion ends. A high trough reflects drug accumulation and increases the risk of nephrotoxicity and ototoxicity. Nephrotoxicity is usually reversible, but ototoxicity (hearing loss, tinnitus, vertigo) can be permanent.
What patient teaching is important for Gentamicin (peak and trough)?
Report any ringing in the ears, hearing changes, or dizziness right away. Drink plenty of fluids unless your provider restricts them. Blood will be drawn at specific times to keep the drug at a safe level. Report any decrease in your urination.
✨
Quick Tip
Gentamicin is a bactericidal aminoglycoside with a narrow therapeutic window requiring serum level monitoring.