AMIKACIN SULFATE
Clinical safety rating: avoid
Positive evidence of fetus risks but benefits may outweigh risks in some cases
Aminoglycoside antibiotic that irreversibly binds to the 30S ribosomal subunit, causing misreading of mRNA and inhibiting protein synthesis. Also disrupts bacterial cell membrane integrity.
| Metabolism | Amikacin is not significantly metabolized; it is excreted unchanged primarily by glomerular filtration. Minimal hepatic metabolism. |
| Excretion | Renal: >90% unchanged via glomerular filtration. Biliary/fecal: <1%. |
| Half-life | Terminal: 2-3 hours (normal renal function); prolonged to 30-50 hours in anuria; neonates 4-8 hours. |
| Protein binding | 0-11% (low binding to albumin). |
| Volume of Distribution | 0.25-0.4 L/kg; approximates extracellular fluid volume; increased in edema, decreased in dehydration. |
| Bioavailability | IM: nearly 100% (rapid and complete). |
| Onset of Action | IM: 30-90 minutes; IV: immediate (infusion complete). |
| Duration of Action | 8-12 hours (normal renal function); extended in renal impairment; trough monitoring guides dosing. |
15 mg/kg/day IV or IM divided every 8-12 hours; typical adult dose 500 mg IV/IM every 12 hours or 7.5 mg/kg every 12 hours.
| Dosage form | INJECTABLE |
| Renal impairment | CrCl 20-50 mL/min: 7.5 mg/kg every 24 hours; CrCl 10-20 mL/min: 7.5 mg/kg every 48 hours; CrCl <10 mL/min: 7.5 mg/kg every 72-96 hours; hemodialysis: 7.5 mg/kg post-dialysis with monitoring. |
| Liver impairment | No dose adjustment required for hepatic impairment; monitor drug levels if severe dysfunction. |
| Pediatric use | Neonates <7 days: 15-20 mg/kg IV every 24-48 hours; neonates 7-28 days: 15 mg/kg every 24 hours; infants/children: 15-22.5 mg/kg/day divided every 8-12 hours; maximum 1.5 g/day. |
| Geriatric use | Reduce initial dose based on renal function; usual dose 7.5 mg/kg every 24-48 hours with close monitoring of serum creatinine and drug levels due to age-related decreased GFR. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Other nephrotoxic or ototoxic drugs like vancomycin or furosemide increase risk of toxicity Monitor peak and trough levels to minimize risk of nephrotoxicity and ototoxicity.
| Breastfeeding | Amikacin is excreted into human milk in low concentrations. The milk-to-plasma ratio is approximately 0.1–0.2. Due to low oral bioavailability from the gastrointestinal tract, systemic effects in the breastfed infant are unlikely. However, caution is advised due to the potential for altered infant gut flora and direct mucosal irritation. Use only if benefits outweigh risks. |
| Teratogenic Risk | Aminoglycosides including amikacin have been associated with fetal ototoxicity and nephrotoxicity when administered during pregnancy. There is a potential for eighth cranial nerve damage and renal impairment in the fetus, particularly during the second and third trimesters. Animal studies have shown evidence of harm, but controlled human studies are lacking. Use only if clearly needed and if safer alternatives are unavailable. |
■ FDA Black Box Warning
WARNING: Amikacin can cause neurotoxicity, ototoxicity, and nephrotoxicity. The risk of nephrotoxicity is greater in patients with impaired renal function and those receiving high doses or prolonged therapy. Ototoxicity may be irreversible and can occur even after drug discontinuation. Monitor renal function and drug levels closely.
| Common Effects | Nephrotoxicity |
| Serious Effects |
["Hypersensitivity to amikacin, other aminoglycosides, or any component of the formulation.","Preexisting severe renal impairment (unless life-threatening infection and no alternative).","Concurrent use of other nephrotoxic or ototoxic drugs (relative contraindication).","Myasthenia gravis (caution; neuromuscular blocking effect)."]
| Precautions | ["Nephrotoxicity: Risk increased with advanced age, pre-existing renal impairment, concomitant use of other nephrotoxic drugs (e.g., amphotericin B, cyclosporine, NSAIDs).","Ototoxicity: Can cause irreversible bilateral hearing loss, tinnitus, and vestibular damage. Monitor audiometry in patients with risk factors.","Neuromuscular blockade: May exacerbate weakness in patients with neuromuscular disorders (e.g., myasthenia gravis, Parkinsonism). Use with caution during anesthesia or with neuromuscular blocking agents.","Hypersensitivity reactions: Including rash, drug fever, and anaphylaxis.","Superinfection: Prolonged use may lead to overgrowth of nonsusceptible organisms.","Pregnancy: Risk of fetal harm (ototoxicity) if administered during pregnancy."] |
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| Fetal Monitoring | Monitor maternal renal function (serum creatinine, BUN), audiometry (baseline and periodic), and drug trough concentrations to avoid toxicity. In the fetus, consider monitoring for signs of growth restriction or anhydramnios (if prolonged therapy). Neonatal assessment for renal function and hearing after delivery if used near term. |
| Fertility Effects | Amikacin has not been reported to adversely affect human fertility. However, aminoglycosides may cause testicular toxicity in animal studies at high doses. Clinical relevance in humans is unknown. |
| Food/Dietary | No significant food interactions. Avoid alcohol as it may increase side effects like dizziness. |
| Clinical Pearls | Monitor peak (15-30 mcg/mL) and trough (<5 mcg/mL) levels to avoid nephrotoxicity and ototoxicity. Adjust dose in renal impairment using CrCl. Synergy with beta-lactams for Gram-negative infections. Avoid concurrent loop diuretics. |
| Patient Advice | Take exactly as prescribed; do not skip doses or stop early. · Report any hearing loss, tinnitus, dizziness, or vertigo immediately. · Drink plenty of fluids to maintain hydration, unless contraindicated. · Avoid taking other medications without consulting your doctor, especially water pills or other antibiotics. |