Amikacin

Oral Antibiotics

Drug class: Aminoglycoside Antibiotics

Amikacin (AMIKIN)（中文：阿米卡星）

Common Strengths

• Injection: 250 mg/2 mL
• Injection: 500 mg/2 mL

Drug Trade Names

Amikin

Drug Usage

Amikacin is used for treating:

• Serious bacterial infections, particularly those resistant to other antibiotics.
• Infections caused by multidrug-resistant strains of bacteria, including Pseudomonas aeruginosa and Acinetobacter species.
• It may also be used for non-tubercular mycobacterial infections when first-line treatment fail.

Mechanism of Action

Amikacin binds to the 30S ribosomal subunit of bacteria, inhibiting protein synthesis. This interference leads to the productions of non-functional proteins, ultimately killing the bacteria.

Route of Administration

The aminoglycosides are not absorbed from the gut and must therefore be given by injection for systemic infections. Amikacin is administered via:

• Intravenous (IV)
• Intramuscular (IM)
• Inhalation (in specific formulations)

Dosages

General dosing for adults with normal renal function is:

• 15 mg/kg/day, divided into doses every 8 to 12 hours.

Side Effects

Frequency	Adverse reactions
Common Side Effect	Nausea
	Vomiting
	Injection site pain
	Loss of appetite
Serious Side Effect	Nephrotoxicity (kidney damage)
	Ototoxicity (hearing loss)
	Neuromuscular blockade
	Allergic reactions such as anaphylaxis

Pharmacokinetics

Absorption:

• Amikacin is poorly absorbed when taken orally; thus, it must be administered parenterally (intravenously or intramuscularly).
• After intramuscular administration, peak serum concentrations are typically reached within 0.5 to 2 hours. For intravenous administration, peak levels can occur immediately after infusion.

Metabolism:

• Amikacin is not metabolized significantly in the body;
• About 98-99% of the administered dose is excreted unchanged in the urine.
• Only a small fraction (1-2%) is excreted via bile.

Elimination:

• The elimination half-life of amikacin ranges from 2 to 3 hours in individuals with normal renal function. However, this can increase significantly in patients with renal impairment.
• The drug is primarily cleared by the kidneys through glomerular filtration. In patients with reduced kidney function, dosing intervals must be adjusted to prevent accumulation and potential toxicity.

Drug Precautions

Pregnancy

Amikacin is generally not recommended during pregnancy due to potential risks of congenital deafness in infants.

Breastfeeding

Amikacin can pass into breast milk; consult a healthcare provider before breastfeeding.

Children and Elderly

Use with caution in children and elderly patients due to increased sensitivity to side effects.

Drug Monitoring Items

Regular monitoring of kidney function, hearing test, and serum drug levels is recommended during treatment.

Drug Interactions

Amikacin may interact with:

• Furosemide: This diuretic can enhance the nephrotoxic effects of amikacin, increasing the risk of kidney damage.
• Vancomycin: Concurrent use can lead to increased nephrotoxicity.
• Cisplatin and Amphotericin B: Both are nephrotoxic and should be avoided alongside amikacin.
• Neuromuscular blockers (e.g. succinylcholine): Amikacin can exacerbate neuromuscular blockade, leading to respiratory paralysis in susceptible individuals.