Iv%252525252525252525252520gentamicin

# IV Gentamicin ## Overview Gentamicin is an aminoglycoside antibiotic that exerts bactericidal activity by binding to the 30S ribosomal subunit, inhibiting bacterial protein synthesis. It provides coverage against aerobic Gram-negative bacilli, including *Pseudomonas aeruginosa*, and acts synergistically against certain Gram-positive organisms (e.g., *Staphylococci*, *Enterococci*). ## Primary Indications * Serious Gram-negative infections (sepsis, complicated UTI, pneumonia, intra-abdominal infections). * Synergistic treatment for infective endocarditis. * Empiric treatment for suspected neonatal sepsis. ## Adult Dosing * **Traditional/Multiple Daily Dosing:** 1–2.5 mg/kg every 8–12 hours. * **Extended-Interval (Once-Daily) Dosing:** 5–7 mg/kg every 24 hours. *Note: Local institutional protocols for nomograms (e.g., Hartford Nomogram) determine specific intervals based on serum concentrations.* * **Synergy for Endocarditis:** 1 mg/kg every 8 hours. ## Pediatric Dosing * **Neonatal (0–7 days):** 2.5–5 mg/kg every 12–24 hours (dosage depends heavily on gestational and postnatal age). * **Infants/Children:** 2.5 mg/kg every 8 hours (traditional) or 5–7.5 mg/kg every 24 hours (extended-interval). * *Note: Always consult institutional guidelines (e.g., Neofax) for neonatal dosing as regimens vary based on post-menstrual age.* ## Dose Adjustments * **Renal Impairment:** Required. Calculate CrCl (Cockcroft-Gault). In traditional dosing, increase the interval. In extended-interval dosing, do not use if CrCl < 30–40 mL/min; use traditional dosing instead. * **Obesity:** Use Adjunctive Body Weight (ABW) or Adjusted Body Weight to prevent toxicity. ## Contraindications * Hypersensitivity to aminoglycosides. * Use with caution in patients with pre-existing vestibular/auditory nerve damage or myasthenia gravis (may exacerbate muscle weakness). ## Adverse Effects * **Nephrotoxicity:** Usually reversible; associated with prolonged trough levels. * **Ototoxicity:** Auditory (tinnitus, hearing loss) and vestibular (vertigo); often irreversible. * **Neuromuscular Blockade:** Rare but severe, especially with rapid infusion. ## Key Drug Interactions * **Nephrotoxic Agents:** Increased risk with vancomycin, amphotericin B, cyclosporine, tacrolimus, or NSAIDs. * **Ototoxic Agents:** Increased risk with loop diuretics (e.g., furosemide). * **Neuromuscular Blockers:** Potential for prolonged paralysis. ## Monitoring * **Serum Concentrations:** * **Trough:** Draw 30 minutes before the 3rd or 4th dose. Target typically < 1–2 mcg/mL. * **Peak:** Draw 30 minutes after completion of 30-minute IV infusion. Target varies by infection (typically 5–10 mcg/mL). * **Renal Function:** Monitor serum creatinine and BUN daily. * **Auditory/Vestibular:** Monitor for hearing changes, tinnitus, or balance issues. ## Clinical Pearls * **Administration:** Infuse over 30–60 minutes. * **Synergy:** When used for synergy (e.g., endocarditis), lower doses are used and monitoring is less frequent than in high-dose treatment. * **Uncertainty:** Dosing is highly patient-specific. If the patient has unstable renal function or extremes of body weight, perform therapeutic drug monitoring (TDM) aggressively. *** **Educational Disclaimer:** This information is for educational purposes only. Drug dosing, contraindications, and monitoring parameters must be verified against current institutional protocols, the package insert, and clinical pharmacology databases before prescribing or administering medication.