An aminoglycoside antibiotic given IV or IM for serious infections, especially from gram-negative bacteria such as Pseudomonas and E. coli. It can damage the kidneys and the inner ear, sometimes permanently, so peak and trough blood levels, kidney function, and hearing are monitored.
Gentamicin kills bacteria by disrupting the way they make proteins. It acts on a wide range of bacteria, including staph strains that resist penicillin and methicillin. Most strep bacteria and germs that grow without oxygen resist it. Paired with penicillin, though, it kills certain strep bacteria far better than either drug does alone.
Given into a muscle, it reaches its highest blood level within 30 to 60 minutes and can still be measured in the blood for six to eight hours. The kidneys clear almost all of it unchanged, and a small amount lingers in kidney tissue. If the kidneys are weak, or with high doses or long courses, it builds up and can damage the kidneys and the inner ear, causing dizziness, ringing, or hearing loss that is usually permanent. Using it with other drugs that harm the kidneys or ears, including strong water pills such as furosemide, raises this risk.
Gentamicin is an injected antibiotic for serious infections caused by certain bacteria, including Pseudomonas, E. coli, Klebsiella, and staph. It treats infections of the blood, urinary tract, lungs, gut and abdomen, skin, bones, and burns, as well as meningitis, a serious infection of the brain and spinal cord. It is also used for bacterial blood infections in newborns. It works by killing bacteria, so it does not help colds, flu, or other viral infections.
It is given into a vein or a muscle in the hospital or, for some people, at home. In serious infections, it is often started along with a penicillin-type or cephalosporin antibiotic before lab tests identify the germ, and it is paired with a penicillin for some heart valve infections. For staph infections it is not a first choice and is used when penicillins or other less toxic drugs cannot be. It is not used for a simple first urinary infection unless other, safer antibiotics will not work.
The label's boxed warning treats kidney damage and damage to hearing and balance as the main dangers. Ear damage can show up as dizziness, spinning, ringing or roaring in the ears, or hearing loss, and it is usually permanent. It also warns about numbness, tingling, muscle twitching, seizures, and dangerous muscle weakness with anesthesia or muscle relaxants. Low magnesium, calcium, and potassium, rash, nausea, and harm to an unborn baby's hearing are also possible.
This is the boxed warning, the warning the FDA label prints first.
Nephrotoxicity and neurotoxicity. Gentamicin can damage the kidneys and both the hearing and balance branches of the eighth cranial nerve; ear damage is usually irreversible. Risk rises with renal impairment, high doses, prolonged therapy, older age, dehydration, and other nephrotoxic or ototoxic drugs. Monitor renal function and eighth nerve function, and serum levels when feasible: avoid prolonged peaks above 12 mcg/mL and troughs above 2 mcg/mL. Avoid potent diuretics such as furosemide. Aminoglycosides can harm the fetus.
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