Iv%252525252525252525252525252525252525252520gentamicin

# Gentamicin (IV) ## Overview Gentamicin is an aminoglycoside antibiotic that inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit. It is concentration-dependent, bactericidal, and primarily active against Gram-negative bacilli, including *Pseudomonas aeruginosa*. ## Primary Indications * Serious Gram-negative infections (e.g., sepsis, pneumonia, intra-abdominal infections). * Synergistic treatment for Gram-positive endocarditis (e.g., *Staphylococcus*, *Enterococcus*). * Prophylaxis or treatment of neonatal sepsis. ## Adult Dosing * **Traditional Dosing:** 1–2.5 mg/kg every 8–12 hours. * **Extended-Interval (Once-Daily) Dosing:** 5–7 mg/kg IV every 24 hours. * **Synergy for Endocarditis:** 1 mg/kg every 8–12 hours (typically capped at 80 mg per dose). * *Note: Dosing must be based on Ideal Body Weight (IBW) or Adjusted Body Weight if obese.* ## Pediatric Dosing * **Neonates (0–7 days):** 4–5 mg/kg every 24–48 hours (based on gestational age). * **Infants/Children:** 2.5 mg/kg every 8 hours. * *Consult local protocols (e.g., Neofax or hospital-specific guidelines) as pediatric dosing is highly dependent on weight, gestational age, and postnatal age.* ## Dose Adjustments * **Renal Impairment:** Dosing frequency must be extended based on creatinine clearance (CrCl). * **Obesity:** Use IBW for dosing; if actual body weight is >20% above IBW, use adjusted body weight. * **Hepatic Impairment:** No standard adjustment required, but use with caution. ## Contraindications * Known hypersensitivity to gentamicin or other aminoglycosides. * Use with extreme caution in patients with myasthenia gravis or pre-existing renal impairment. ## Adverse Effects * **Nephrotoxicity:** Usually reversible; associated with accumulation of drug in proximal tubule cells. * **Ototoxicity:** Auditory (tinnitus, hearing loss) and vestibular (vertigo, ataxia) damage; often permanent. * **Neuromuscular Blockade:** Rare, but can occur, especially with rapid IV infusion or in predisposed patients. ## Key Drug Interactions * **Nephrotoxic Agents:** Increased risk of renal failure (e.g., vancomycin, amphotericin B, cisplatin, NSAIDs, loop diuretics). * **Neuromuscular Blocking Agents:** Potentiation of blockade (e.g., succinylcholine, rocuronium). ## Monitoring * **Renal Function:** Serum creatinine and urine output. * **Therapeutic Drug Monitoring (TDM):** * **Traditional:** Obtain troughs 30 minutes before the 3rd or 4th dose; peaks obtained 30 minutes post-infusion. * **Extended-Interval:** Use Hartford Nomogram or similar; measure a "random level" 6–14 hours post-infusion. * **Signs of Toxicity:** Auditory testing if therapy is prolonged (>14 days). ## Clinical Pearls * **Infusion Time:** Always infuse over 30–60 minutes to prevent infusion-related neuromuscular blockade. * **Synergy:** When used for synergy (e.g., endocarditis), serum levels are not typically required unless the patient has renal impairment. * **Local Protocols:** Always verify institutional antibiograms and dosing nomograms before initiation. *** **Educational Disclaimer:** This information is for educational purposes only. Clinical settings vary significantly. Always verify current prescribing information, institutional protocols, and patient-specific factors with a pharmacist or physician before administering medication.