Iv%25252525252520gentamicin

# 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 potent activity against aerobic Gram-negative bacilli, including *Pseudomonas aeruginosa*. ## Primary Indications * Serious Gram-negative infections (e.g., sepsis, complicated UTI, intra-abdominal infections). * Synergistic treatment for Gram-positive endocarditis (typically in combination with cell-wall active agents). ## Adult Dosing * **Traditional (Multiple Daily Dose):** 3–5 mg/kg/day divided every 8 hours. * **Extended Interval (Once-Daily) Dosing:** 5–7 mg/kg administered every 24 hours (based on CrCl). *Note: Follow local institutional protocols for specific nomograms (e.g., Hartford nomogram).* * **Synergy Dosing (Endocarditis):** 1 mg/kg every 8 hours (goal trough <1 mcg/mL). ## Pediatric Dosing * **Neonates (Post-menstrual age dependent):** 2.5–5 mg/kg per dose, frequency determined by gestational age (every 18–48 hours). * **Infants/Children/Adolescents:** 2.5 mg/kg per dose every 8 hours (traditional) or 5–7 mg/kg per dose every 24 hours (extended interval). * *Consult institutional dosing guidelines specific to neonatal/pediatric weight-based protocols.* ## Dose Adjustments * **Renal Impairment:** Mandatory in CrCl <60 mL/min. Adjust both dose and interval based on calculated CrCl or measured serum concentrations. Avoid in dialysis unless specified by a Nephrology protocol. * **Obesity:** Use Adjusted Body Weight (ABW) for calculations to avoid toxicity. ## Contraindications * Hypersensitivity to aminoglycosides. * History of severe reaction to any aminoglycoside. * Use with caution in patients with myasthenia gravis or neuromuscular disorders. ## Adverse Effects * **Nephrotoxicity:** Usually reversible; associated with prolonged high troughs. * **Ototoxicity:** Often irreversible; presents as vestibular dysfunction or sensorineural hearing loss. * **Neuromuscular Blockade:** Rare; potential for respiratory paralysis at high concentrations. ## Key Drug Interactions * **Nephrotoxic Agents:** Increased risk with vancomycin, amphotericin B, cisplatin, cyclosporine, and NSAIDs. * **Neuromuscular Blockers:** May potentiate effects (e.g., succinylcholine). * **Loop Diuretics:** Increased risk of ototoxicity (e.g., furosemide, bumetanide). ## Monitoring * **Serum Concentrations:** * *Traditional:* Trough (30 mins prior to 3rd/4th dose), Peak (30 mins after infusion). * *Extended:* Random level based on nomogram (usually 6–14 hours post-infusion). * **Renal Function:** Monitor SCr and BUN daily. * **Clinical:** Monitor for signs of hearing loss, dizziness, or vertigo. ## Clinical Pearls * Gentamicin has very poor tissue penetration into the CNS and eyes; it should not be relied upon as monotherapy for meningitis or endophthalmitis. * In synergy dosing, the aim is to enhance bacterial killing of Gram-positive organisms (e.g., *Staphylococcus* or *Enterococcus*) without maximizing serum levels that cause toxicity. * Always check the most recent serum creatinine before administering the dose in hospitalized patients. *** *Disclaimer: This information is for educational purposes only. Dosing protocols vary significantly by institution and patient-specific factors (e.g., renal function, weight, infection site). Always verify doses, contraindications, and monitoring requirements via local clinical decision support tools or a current pharmacist-verified formulary before prescribing or administering.*