Last reviewed 2026-04-20 · How we verify

Garamycin (GENTAMICIN)

At a glance

Approved indications

• Bacterial conjunctivitis
• Bacterial infection due to Klebsiella pneumoniae
• Bacterial infection due to Serratia
• Bacterial infection of skin
• Bacterial keratitis
• Bacterial meningitis
• Bacterial pneumonia
• Bacterial septicemia
• Blepharoconjunctivitis
• Burn Wound Infections
• Cholangitis
• Citrobacter Pneumonia
• Citrobacter Septicemia
• Complicated Bacterial Peritonitis
• Complicated UTI with Pseudomonas Aeruginosa
• Complicated Urinary Tract Infections
• Dacryocystitis
• Enterobacter Pneumonia
• Folliculitis
• Furunculosis

Boxed warnings

• BOXED WARNINGS Patients treated with aminoglycosides should be under close clinical observation because of the potential toxicity associated with their use. As with other aminoglycosides, gentamicin injection is potentially nephrotoxic. The risk of nephrotoxicity is greater in patients with impaired renal function and in those who receive high dosage of prolonged therapy. Neurotoxicity manifested by ototoxicity, both vestibular and auditory, can occur in patients treated with gentamicin, primarily in those with pre-existing renal damage and in patients with normal renal function treated with higher doses and/or for longer periods than recommended. Aminoglycoside-induced ototoxicity is usually irreversible. Other manifestations of neurotoxicity may include numbness, skin tingling, muscle twitching and convulsions. Renal and eighth cranial nerve function should be closely monitored, especially in patients with known or suspected reduced renal function at onset of therapy and also in those whose renal function is initially normal but who develop signs of renal dysfunction during therapy. Urine should be examined for decreased specific gravity, increased excretion of protein and the presence of cells or casts. Blood urea nitrogen (BUN), serum creatinine or creatinine clearance should be determined periodically. When feasible, it is recommended that serial audiograms be obtained in patients old enough to be tested, particularly high-risk patients. Evidence of ototoxicity (dizziness, vertigo, tinnitus, roaring in the ears or hearing loss) or nephrotoxicity requires dosage adjustment or discontinuance of the drug. As with the other aminoglycosides, on rare occasions changes in renal and eighth cranial nerve function may not become manifest until soon after completion of therapy. Serum concentrations of aminoglycosides should be monitored when feasible to assure adequate levels and to avoid potentially toxic levels. When monitoring gentamicin peak concentrations, dosage should be adjusted so that prolonged levels above 12 mcg/mL are avoided. When monitoring gentamicin trough concentrations, dosage should be adjusted so that levels above 2 mcg/mL are avoided. Excessive peak and/or trough serum concentrations of aminoglycosides may increase the risk of renal and eighth cranial nerve toxicity. In the event of overdosage or toxic reactions, hemodialysis may aid in the removal of gentamicin from the blood, especially if renal function is, or becomes, compromised. The rate of removal of gentamicin is considerably lower by peritoneal dialysis than it is by hemodialysis. In the newborn infant, exchange transfusions may also be considered. Concurrent and/or sequential systemic or topical use of other potentially neurotoxic and/or nephrotoxic drugs, such as cisplatin, cephaloridine, kanamycin, amikacin, neomycin, polymyxin B, colistin, paromomycin, streptomycin, tobramycin, vancomycin and viomycin, should be avoided. Other factors which may increase patient risk of toxicity are advanced age and dehydration. The concurrent use of gentamicin with potent diuretics, such as ethacrynic acid or furosemide, should be avoided, since certain diuretics by themselves may cause ototoxicity. In addition, when administered intravenously, diuretics may enhance aminoglycoside toxicity by altering the antibiotic concentration in serum and tissue. Aminoglycosides can cause fetal harm when administered to a pregnant woman (see WARNINGS section).

Common side effects

• ocular burning
• irritation upon drug instillation
• non-specific conjunctivitis
• conjunctival epithelial defects
• conjunctival hyperemia
• allergic reactions
• thrombocytopenic purpura
• hallucinations
• bacterial and fungal corneal ulcers

Drug interactions

• cisatracurium
• metocurine
• mezlocillin
• mivacurium
• pancuronium
• pentamidine
• pipecuronium
• piperacillin
• rocuronium
• suxamethonium
• ticarcillin
• torsemide

Key clinical trials

• Intra-nodal Injection of Gentamicin for the Treatment of Suppurated Cat Scratch Disease's Lymphadenitis (PHASE3)
• Prophylaxis Against Surgical Site Infections Using Local as Well as Systemic Antibiotic (NA)
• Prophylactic Antibiotic Coated Nail to Prevent Infection: A Clinical Trial (PHASE4)
• Aminoglycosides in Early Sepsis (PHASE4)
• Efficacy of Local Gentamicin Containing Collagen In Prevention of Post Stermotomy Infection In Cardiac Surgery (NA)
• Dual vs. Single-Antibiotic Impregnated Cement in Hemiarthroplasty for Femoral Neck Fracture (PHASE3)
• Extended Interval Dosing of Gentamicin in Neonates
• Multichannel Vestibular Implant Early Feasibility Study (NA)

Primary sources

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