Sisomicin

Chemical structure of Sisomicin

Sisomicin is an aminoglycoside antibiotic that is derived from the bacterium Micromonospora inyoensis. It is closely related to other aminoglycosides such as gentamicin and netilmicin. Sisomicin is primarily used in the treatment of serious bacterial infections caused by Gram-negative bacteria.

Mechanism of Action

Sisomicin, like other aminoglycosides, works by binding to the 30S ribosomal subunit of the bacterial ribosome. This binding interferes with the initiation complex of protein synthesis, leading to the misreading of mRNA and the production of nonfunctional or toxic peptides. The disruption of protein synthesis ultimately results in bacterial cell death, making sisomicin a bactericidal agent.

Clinical Uses

Sisomicin is used to treat a variety of infections, including:

• Urinary tract infections
• Respiratory tract infections
• Skin and soft tissue infections
• Intra-abdominal infections

It is particularly effective against Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae.

Administration and Dosage

Sisomicin is typically administered via intravenous or intramuscular injection. The dosage depends on the severity of the infection, the patient's renal function, and the susceptibility of the causative organism. It is important to monitor renal function and serum drug levels during treatment to avoid nephrotoxicity and ototoxicity, which are common side effects of aminoglycosides.

Side Effects

Common side effects of sisomicin include:

• Nephrotoxicity
• Ototoxicity
• Neuromuscular blockade

Patients receiving sisomicin should be monitored for signs of kidney damage and hearing loss. The risk of these side effects is increased in patients with pre-existing renal impairment or those receiving concurrent nephrotoxic drugs.

Resistance

Bacterial resistance to sisomicin can occur through several mechanisms, including:

• Enzymatic modification of the drug by aminoglycoside-modifying enzymes
• Alteration of the ribosomal binding site
• Reduced uptake of the drug into the bacterial cell

Resistance is a significant concern in the clinical use of aminoglycosides, and susceptibility testing is recommended before initiating therapy.

Related Pages

• Aminoglycoside
• Antibiotic resistance
• Gentamicin
• Netilmicin