Garamycin Injection: An Effective Antibiotic for Bacterial Infections

Bacterial infections are a common health concern that can cause serious complications if left untreated. Garamycin* Injection is a brand of gentamicin sulfate, an aminoglycoside antibiotic that is used for intramuscular and intravenous administration. It is an aqueous solution containing gentamicin sulfate equivalent to 40 mg gentamicin base per ml. Garamycin Injection is known for its broad-spectrum activity against a wide range of Gram-negative and Gram-positive bacteria, making it an effective treatment option for various types of infections.

Actions and Microbiological Activity

  • Bactericidal Effect: Garamycin Injection acts as a bactericidal antibiotic, meaning it kills susceptible microorganisms. It inhibits protein synthesis in bacteria, leading to their destruction. Studies have shown its effectiveness against a variety of pathogenic bacteria, including Escherichia coli, Proteus sp., Pseudomonas aeruginosa, Klebsiella-Enterobacter-Serratia group, Staphylococcus sp., and Neisseria gonorrhoeae.
  • Synergistic Effect: Garamycin Injection has been found to have a synergistic bactericidal effect when combined with certain other antibiotics. For example, the combination of gentamicin and penicillin G shows enhanced killing effects against Streptococcus faecalis and its varieties. Synergism has also been observed with combinations of gentamicin and cephalosporins or carbapenems against certain Gram-negative organisms.
  • Activity Against Resistant Bacteria: Garamycin Injection may still be effective against bacterial strains that are resistant to other aminoglycosides. It is important to note that bacteria resistant to one aminoglycoside may also show resistance to others.

Indications and Usage

Garamycin Injection is indicated for the treatment of infections caused by susceptible strains of the following microorganisms:

  • Pseudomonas aeruginosa
  • Proteus sp. (indole-positive and indole-negative)
  • Escherichia coli
  • Klebsiella-Enterobacter-Serratia Sp.
  • Providencia sp.
  • Staphylococcus sp. (coagulase-positive and coagulase-negative, including penicillin and methicillin-resistant strains)
  • Neisseria gonorrhoeae

Clinical studies have shown the effectiveness of Garamycin Injection in various conditions, including:

  • Sepsis and bacteremia (including neonatal sepsis)
  • Central nervous system infections (including meningitis)
  • Kidney and genitourinary tract infections
  • Respiratory tract infections
  • Gastrointestinal tract infections
  • Skin, bone, or soft tissue infections (including burns and wounds)
  • Intra-abdominal infections (including peritonitis)
  • Ocular infections

Garamycin Injection can be considered as initial therapy for suspected or confirmed Gram-negative infections. The decision to continue therapy should be based on susceptibility test results, the patient’s clinical response, and tolerance to the drug. In serious infections with unknown causative microorganisms, Garamycin Injection may be administered as initial therapy in combination with a penicillin or cephalosporin-type drug before obtaining susceptibility test results.

Dosage and Administration

The recommended dosage for Garamycin Injection depends on the route of administration and the patient’s renal function. Here are the guidelines:

Intramuscular Administration:

  • Adults with normal renal function: The recommended dosage for serious infections is 3 mg/kg/day, divided into three equal doses every eight hours or two equal doses every 12 hours. Dosage adjustment is necessary for patients with renal impairment.
  • Pediatric patients: The dosage varies based on age and weight. Premature or full-term neonates up to one week of age may receive 5-6 mg/kg/day, while neonates over one week and infants can receive 7.5 mg/kg/day. Children can be given 2-7.5 mg/kg/day.

Intravenous Administration:

  • Garamycin Injection can be diluted in sterile normal saline or a solution of dextrose 5% in water. The infusion may be given over a period of one-half to two hours, depending on the patient’s condition.

Dosage adjustment is necessary for patients with impaired renal function. Monitoring of renal function and gentamicin serum levels is important to ensure adequate but not excessive drug levels.

Adverse Reactions and Precautions

Garamycin Injection, like other aminoglycosides, may cause adverse reactions. Some of the common side effects include nephrotoxicity (kidney damage) and neurotoxicity (affecting the vestibular and auditory nerves). Other possible adverse reactions include respiratory depression, skin reactions, visual disturbances, and gastrointestinal symptoms. Precautions should be taken in patients with renal impairment, neuromuscular disorders, or a history of allergic reactions to gentamicin or other aminoglycosides.

It is important to note that Garamycin Injection contains sodium bisulfite, which can cause allergic reactions in susceptible individuals.

Contraindications and Pregnancy

Garamycin Injection is contraindicated

in individuals with a known hypersensitivity or serious toxic reactions to gentamicin or other aminoglycosides. Pregnant women should use caution when using Garamycin Injection, as aminoglycosides can potentially cause harm to the fetus. The decision to use the drug should be made after considering the potential benefits and risks.


Garamycin Injection, containing gentamicin sulfate, is a potent antibiotic with a broad spectrum of activity against both Gram-negative and Gram-positive bacteria. It is an effective treatment option for various bacterial infections, including septicemia, respiratory tract infections, urinary tract infections, and skin and soft tissue infections. The dosage and administration of Garamycin Injection should be carefully adjusted based on the patient’s renal function to ensure optimal efficacy and minimize the risk of adverse effects. Patients should be monitored for potential side effects, particularly nephrotoxicity and neurotoxicity.

As with any medication, it is crucial to follow the guidance and prescriptions provided by healthcare professionals. Garamycin Injection plays a vital role in combating bacterial infections and promoting patient recovery.