Overview

Amikacin is a semi-synthetic aminoglycoside antibiotic that is derived from kanamycin. Amikacin is an antibiotic used for a number of bacterial infections. This includes joint infections, intra-abdominal infections, meningitis, pneumonia, sepsis, and urinary tract infections. It is also used for the treatment of multidrug-resistant tuberculosis. It is used either by injection into a vein or muscle.
Amikacin's unique property is that it exerts activity against more resistant gram-negative bacilli such as Acinetobacter baumanii and Pseudomonas aeruginosa. Amikacin also exerts excellent activity against most aerobic gram-negative bacilli from the Enterobacteriaceae family, including Nocardia and some Mycobacterium (M. avium-intracellulare, M. chelonae, and M. fortuitum). Several forms of amikacin are used currently, including an intravenous (IV) or intramuscular (IM) injection.6 In September 2018, a liposomal inhalation suspension of this drug was approved by the FDA for the treatment of lung disease caused by Mycobacterium avium complex (MAC) bacteria in a small population of patients with the disease who do not respond to traditional treatment.

Indications

The amikacin sulfate injection is indicated in the short-term treatment of serious bacterial infections ,effective in bacterial septicemia (including neonatal sepsis); in serious infections of the respiratory tract, bones and joints, central nervous system

Side Effects

persistent cough

fatigue, weight loss

night sweats

shortness of breath

the coughing up of blood

diarrhea

spinning sensation (vertigo)

numbness

dizziness

ringing or roaring in the ears

Contraindications

hypersensitivity to Amikacin is a contraindication for its use or serious toxic reactions to aminoglycosides may contraindicate the use of any other aminoglycoside

Pharmacology

Mechanism of action

The primary mechanism of action of amikacin is the same as that for all aminoglycosides. It binds to bacterial 30S ribosomal subunits and interferes with mRNA binding and tRNA acceptor sites, interfering with bacterial growth. This leads to disruption of normal protein synthesis and production of non-functional or toxic peptides. Other actions have been postulated for drugs of this class Amikacin, as well as the rest of the aminoglycosides, are generally bacteriocidal against gram-positive and gram-negative bacteria.

Pharmacodynamics

Amikacin is an aminoglycoside antibiotic. Aminoglycosides bind to the bacteria, causing misreading of t-RNA, leaving bacteria unable to synthesize proteins vital to their growth. Aminoglycosides are useful mainly in the treatment infections involving aerobic, Gram-negative bacteria, such as Pseudomonas, Acinetobacter, and Enterobacter. In addition, some mycobacteria, including the bacteria that cause tuberculosis, are susceptible to aminoglycosides. Infections caused by Gram-positive bacteria can also be treated with aminoglycosides, however, other antibiotics may be more potent and less toxic to humans.

Pharmacokinetics

Absorption: Rapidly absorbed after intramuscular administration. Rapid absorption occurs from the peritoneum and pleura. Poor oral and topical absorption. Poorly absorbed from bladder irrigations and intrathecal administration. The bioavailability of this drug is expected to vary primarily from individual differences in nebulizer efficiency and airway pathology.Following IM administration of a single dose of amikacin of 7.5 mg/kg in adults with normal renal function, peak plasma amikacin concentrations of 17-25 micrograms/mL are attained within 45 minutes to 2 hours. Following IV infusion of the same dose given over 1 hour peak plasma concentrations of the drug average 38 micrograms/mL immediately following the infusion, 5.5 micrograms/mL at 4 hours, and 1.3 micrograms/mL at 8 hours
Distribution: usual dosages of amikacin, amikacin has been found in bone, heart, gallbladder, and lung tissue. Amikacin is also distributed into bile, sputum, bronchial secretions, and interstitial, pleural, and synovial fluids
Metabolism: Amikacin's structure has been altered to reduce the possible route of enzymatic deactivation, thus reducing bacterial resistance. Many strains of Gram-negative organisms resistant to gentamicin and tobramycin have shown to be sensitive to amikacin in vitro
Elimination: This drug is eliminated by the kidneys. In adults with normal renal function, 94-98% of a single IM or IV dose of amikacin is excreted unchanged by glomerular filtration in the kidney within 24 hours. Amikacin can be completely recovered within approximately 10-20 days in patients with normal, healthy renal function.