Amikacin

C. diff Risk

Low

Oral Bioavailability

NA

Approximate Cost

Spectrum Of Activity

Dosing

No adjustment required

Once Daily (OD)/Extended interval dosing Amikacin
15 mg/kg dosing body weight (DBW) IV q24h

Multiple Daily Dose (MDD) Amikacin
7.5 mg/kg dosing body weight (DBW) IV q12h

Cystic Fibrosis (modified extended interval dosing)
15-30 mg/kg dosing body weight (DBW) IV q24h
Consult pharmacy for ALL dosing

Mycobacteria
Specialized dosing - contact Pharmacy and Infectious Diseases

Dosing body weight - see Additional information

General Information

Common Usage

Amikacin is used to treat Gram negative bacilli, including Pseudomonas aeruginosa and used in combination with other antimicrobials for the treatment of some Mycobacteria spp.

All aminoglycosides carry potential for tubular necrosis and renal failure, deafness due to cochlear toxicity, vertigo due to damage to vestibular organs, and rarely, neuromuscular blockade. If considering using amikacin, strongly consider ID consultation and contact Pharmacy to assist with appropriate dosing.

Drug Monitoring

Monitor serum creatinine and urea 2-3 times/week. Discontinue if any signs of vestibulotoxicity or ototoxicity.

All aminoglycosides carry potential for cochlear, renal and vestibulotoxicity. If considering using amikacin, strongly consider ID consultation.

For once daily/extended interval dosing dosing:

  • Peak levels are not recommended

  • NO level is required in patients with normal renal function and therapy anticipated to be less than 8 days

  • Patient populations to consider a serum concentration independent of duration of therapy:

    • critically ill patients
    • rapidly changing renal status
    • increased or rapidly changing Vd (e.g. ascities, burn)
    • serum creatinine is an unreliable indicator of renal function
    • concurrent nephrotoxic therapy (Amphotericin B, vancomycin, chemotherapy, furosemide, cyclosporine or tacrolimus etc.)

A single serum concentration can be drawn between 6 to 14 hours after the start of the aminoglycoside infusion (typically an 8-10 hour post concentration is drawn.)
This concentration is then divided by 2 and then plotted on the Hartford dosing nomogram.

  • Contact Pharmacy to assist in arranging monitoring, level interpretation and dose individualization.

For conventional multiple times per day dosing:

  • Target Peak 20-30 mg/L, Trough <4 mg/L. Peak levels usually not required but if drawn, record time of dose and time of level draw as accurately as possible.

  • Contact pharmacy for monitoring set up, level interpretation and dose individualization
    NB: Trough level is 30-60min BEFORE next dose dose, and peak is 30-60min AFTER dose infused.

For Cystic Fibrosis modified extended interval dosing:

  • Contact pharmacy for monitoring set up, level interpretation and dose individualization

For Intermittent OR Continuous dialysis:

  • Contact pharmacy for monitoring set up, level interpretation and dose individualization

Adverse Effects

Nephrotoxicity (non-oliguric)

  •  Less common with once daily dosing.

  •  Avoid concomitant nephrotoxins.

  •  Greater toxicity with longer duration and supratherapeutic trough levels.

Vestibulocochlear toxicity

  •  Irreversible

  •  Audiology testing required for prolonged use

Other

  •  Can exacerbate neuromuscular blockade (e.g. contraindicated in patients with myasthenia gravis)

Major Interactions

Increased risk of nephrotoxicity with concomitant use of:

  •  Amphotericin B

  •  Cyclosporine

  •  Cisplatin

  •  NSAIDs

  •  Contrast dye

  •  Vancomycin

Increased ototoxicity with:

  •  Furosemide

Respiratory paralysis with:

  •  Neuromuscular blockade agents

Additional Information

All aminoglycosides carry potential for tubular necrosis and renal failure, deafness due to cochlear toxicity, vertigo due to damage to vestibular organs, and rarely, neuromuscular blockade. If considering using amikacin, strongly consider ID consultation and contact Pharmacy to assist with appropriate dosing.

Perform baseline and ongoing weekly otovestibular toxicity assessment. Formal audiology assessment required if symptoms develop.

Inform patient of risk of ototoxicity and to report any symptoms.

Calculation of Dosing Body Weight (DBW)
DBW = IBW + [(ABW - IBW) x 0.4]

where:
IBW male = 50kg + 0.906kg [Height (cm) - 152.4cm]
IBW female = 45kg + 0.906kg [Height (cm) - 152.4cm]

Dosing Body Weight = DBW
Ideal Body Weight = IBW
Actual Body Weight = ABW

Pharmacology

Antimicrobial class: Aminoglycoside

Pregnancy category: D

Average serum half life: 2.5 hours

Biliary penetration: Moderate

CSF penetration: Poor

Lung penetration: Therapeutic

Urine penetration: Therapeutic