Amikacin injection for serious bacterial infections

Amikacin sulfate injection is a sterile antibiotic solution administered by intramuscular or intravenous routes. It is used to treat serious infections caused by specific strains of Gram-negative bacteria and certain staphylococcal infections. Amikacin belongs to the aminoglycoside class of antibiotics and works by inhibiting bacterial protein synthesis.

Amikacin sulfate injection is indicated for short-term treatment of serious infections caused by susceptible Gram-negative bacteria including Pseudomonas, Escherichia coli, Proteus, Providencia, Klebsiella-Enterobacter-Serratia, and Acinetobacter species.

It is effective in bacterial septicemia (including neonatal sepsis), serious respiratory tract infections, bone and joint infections, central nervous system infections including meningitis, skin and soft tissue infections, intra-abdominal infections such as peritonitis, burns, and post-operative infections including post-vascular surgery infections.

Amikacin is also used for complicated and recurrent urinary tract infections caused by susceptible bacteria but is not indicated for uncomplicated initial urinary tract infections unless organisms are resistant to less toxic antibiotics.

It may be used initially before susceptibility test results are available and is effective against certain gentamicin or tobramycin-resistant strains. Amikacin can also treat staphylococcal infections under specific conditions such as allergies to other antibiotics or mixed infections.

Amikacin sulfate

Amikacin is an aminoglycoside antibiotic that binds to bacterial ribosomes, inhibiting protein synthesis and leading to bacterial cell death. It is bactericidal against susceptible Gram-negative and some Gram-positive bacteria. Amikacin resists enzymatic degradation by certain aminoglycoside-inactivating enzymes affecting other drugs in its class, providing activity against resistant bacteria. When combined with beta-lactam antibiotics, it can have a synergistic effect against some Gram-negative organisms.

The dosage and route (intramuscular or intravenous) depend on the severity of infection, renal function, and patient-specific factors. Typical adult doses include 7.5 mg/kg repeated every 12 hours administered either intramuscularly or as a 30-minute intravenous infusion.

Serum levels should be monitored to maintain therapeutic concentrations and avoid toxic levels, with peak serum concentrations not exceeding 35 mcg/mL. Renal function must be assessed before and during therapy to guide dose adjustments.

Treatment duration is usually short term and safety is not established beyond 14 days. In neonates and pediatric patients, dosing requires special consideration due to renal immaturity and altered drug elimination.

Amikacin is contraindicated in patients with a history of hypersensitivity to amikacin or other aminoglycosides due to known cross-sensitivities.

Ototoxicity and nephrotoxicity: Amikacin can cause irreversible hearing loss and kidney damage, particularly in patients with preexisting renal impairment or those receiving high doses or prolonged therapy. Hearing loss often starts with high-frequency deafness detectable only by audiometric tests and may progress to permanent bilateral deafness. Vestibular toxicity may cause vertigo. Renal function must be monitored closely during treatment.

Neuromuscular blockade and respiratory paralysis: These rare but serious reactions can occur, especially in patients receiving neuromuscular blocking agents, anesthetics, or massive transfusions with citrate. Calcium salts may reverse neuromuscular blockade but respiratory support may be required.

Use with caution: Avoid concurrent use with other nephrotoxic or ototoxic drugs such as certain diuretics (ethacrynic acid, furosemide), vancomycin, amphotericin B, and other aminoglycosides. Elderly and dehydrated patients are at higher risk of toxicity.

Pregnancy: Aminoglycosides cross the placenta and can cause fetal harm, including irreversible congenital deafness. Use only if the benefits outweigh risks.

Sulfite sensitivity: Amikacin contains sodium metabisulfite, which can cause allergic reactions including life-threatening asthma attacks in susceptible patients.

Clostridium difficile-associated diarrhea: Amikacin, like other antibiotics, may cause severe diarrhea ranging to fatal colitis. Patients should be monitored for diarrhea during and after therapy.

Mitochondrial DNA variants: Patients with certain mitochondrial gene variants are at increased risk of ototoxicity even at recommended drug levels. Alternative treatments should be considered in such cases.

Common adverse reactions: Nephrotoxicity (kidney damage), ototoxicity (hearing loss, tinnitus, vertigo), neurotoxicity (numbness, skin tingling, muscle twitching, convulsions), and allergic reactions to sulfites.

Serious reactions: Irreversible bilateral deafness, respiratory paralysis, neuromuscular blockade, and severe hypersensitivity reactions such as anaphylaxis.

• Concurrent use with potent diuretics (e.g., ethacrynic acid, furosemide) increases risk of ototoxicity and may alter amikacin serum levels.
• Use with other nephrotoxic or ototoxic agents (bacitracin, cisplatin, amphotericin B, vancomycin, other aminoglycosides) should be avoided to reduce additive toxicity.
• Combination with beta-lactam antibiotics can cause mutual inactivation if administered together by the same route; careful timing and handling of samples for drug levels is required.
• Cephalosporins may spuriously elevate creatinine measurements during concurrent use.
• Aminoglycosides should be used cautiously with neuromuscular blockers or anesthetics due to possible potentiation of neuromuscular blockade.

Pregnancy: Amikacin crosses the placenta and may cause fetal harm including irreversible bilateral deafness. Use only if clearly needed and potential benefits outweigh risks.

Lactation: It is unknown whether amikacin is excreted in human milk. Due to potential serious adverse effects in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug, considering the importance to the mother.

Overdose symptoms can include worsening nephrotoxicity, ototoxicity, and neuromuscular blockade potentially leading to respiratory paralysis. Management requires supportive care and monitoring.

Store the amikacin injection according to the manufacturer's instructions. Specific storage conditions are not detailed in the provided evidence.