Amikacin: Clinical Applications and Treatment Guidelines
Amikacin is primarily indicated for the treatment of serious infections caused by susceptible gram-negative bacteria, including treatment-refractory nontuberculous mycobacterial (NTM) pulmonary disease, particularly Mycobacterium avium complex (MAC). 1
Primary Indications
Amikacin is FDA-approved for:
- Treatment of serious infections due to susceptible gram-negative bacteria, including:
- Pseudomonas species
- Escherichia coli
- Proteus species (both indole-positive and indole-negative)
- Providencia species
- Klebsiella species
- Enterobacter species
- Serratia species
- Acinetobacter species 1
Specialized Applications
Nontuberculous Mycobacterial (NTM) Pulmonary Disease
Amikacin plays a critical role in treating specific cases of MAC pulmonary disease:
- For macrolide-resistant MAC pulmonary disease: Parenteral amikacin is recommended as part of intensified therapy 2
- For cavitary or advanced/severe bronchiectatic MAC disease: Parenteral amikacin improves microbiologic response when added to standard oral therapy 2
- For treatment-refractory MAC pulmonary disease: Amikacin liposomal inhaled suspension (ALIS) is strongly recommended after failure of at least six months of guideline-based therapy 2
Other Important Applications
- Treatment of gentamicin-resistant and tobramycin-resistant gram-negative infections 3
- Part of empiric antibiotic regimens for suspected sepsis in febrile, leukopenic immunocompromised hosts 3
- Combination therapy with beta-lactam antibiotics for serious infections 3
Dosing Guidelines
Standard Dosing
- Adults with normal renal function: 15 mg/kg/day IV or IM as a single daily dose (maximum 1.0 g/day) 4
- Adults over 59 years: Reduced dose of 10 mg/kg/day (maximum 750 mg) 4
- Children: 15-22.5 mg/kg/day IV 4
- Special conditions (cystic fibrosis, febrile neutropenia): Higher doses of 30 mg/kg/day divided every 8 hours may be used 4
Administration and Monitoring
Administration
- Can be given intramuscularly or intravenously (IV infused over 30 minutes) 4
- For patients on dialysis: Administer after dialysis 4
Monitoring Requirements
Baseline assessment:
- Audiogram and vestibular testing
- Romberg testing
- Serum creatinine measurement 4
During treatment:
Potential Toxicities and Precautions
Major Toxicities
- Ototoxicity: Can affect both auditory and vestibular function
- Nephrotoxicity: Risk similar to other aminoglycosides 5, 3
Risk Factors for Toxicity
- Prolonged treatment
- Higher total doses
- Concurrent use of diuretics
- Pre-existing renal impairment
- Advanced age
- Previous exposure to aminoglycosides 4, 6
Contraindications
- Pregnancy: Contraindicated due to risk of fetal nephrotoxicity and congenital hearing loss 4
Clinical Efficacy
- Effective in approximately 81% of cases across various infection types 6
- Particularly effective in:
- Genitourinary infections (90% efficacy)
- Septicemia (85% efficacy)
- Skin, soft tissue, or bone infections (70% efficacy)
- Lower respiratory tract infections (69% efficacy) 6
- Effective in 88% of infections due to gentamicin-resistant pathogens 6
Special Considerations for NTM Disease
- Initial MAC treatment: Inhaled amikacin is not recommended as part of initial treatment regimens 2
- Treatment-refractory MAC: Addition of amikacin liposomal inhaled suspension significantly improves culture conversion rates (29.0% vs 8.9% with standard therapy alone) 2
- Duration of parenteral therapy: At least 2-3 months of aminoglycoside therapy is considered the best balance between risks and benefits for MAC pulmonary disease 2
Important Clinical Pearls
- Amikacin must be paired with adequate companion medications (such as macrolide, ethambutol, and possibly rifampicin and clofazimine) when treating NTM to prevent emergence of resistance 2
- Amikacin has the advantage of being the aminoglycoside least inactivated by semisynthetic penicillins, making it valuable for combination therapy 3
- Regular monitoring is essential to minimize toxicity while ensuring therapeutic efficacy 4