Gentamicin injection is indicated for the following conditions,
when caused by susceptible organisms;
1. Urinary tract infections; (Not indicated for the treatment of
uncomplicated urinary tract infections).
2. Systemic infections, e.g. Septicaemia, peritonitis;
3. Bone and soft-tissue infections, e.g. osteomyelitis, wound and
4. Infected burns;
5. Infections of the respiratory tract e.g. Pneumonia.
Hypersensitivity to gentamicin is a contraindication to its use. A
history of hypersensitivity or serious toxic reactions to other
aminoglycosides may contraindicate use of gentamicin because of the
known cross-sensitivity of patients to drugs in this class.
It can produce irreversible, cumulative ototoxicity affecting both
the cochlea (manifest as hearing loss of higher tones) and more
common, the vestibular system (manifest as dizziness and vertigo).
Concurrent use of an anti-emetic eg. dimenhydrinate may mask the
early symptoms of vestibular ototoxicity.
Reversible nephrotoxicity may occur and acute renal failure has
been reported, often in association with the concurrent
administration of other nephrotoxic agents eg. other aminoglosides,
vancomycin, some cephalosporins, or potentially ototoxic agents
such as ethacrynic acid and furosemide.
Renal impairment is usually mild, although acute tubular necrosis
and interstitial nephritis have occurred. Decreased glomerular
filtration rate is usually seen only after several days, and may
even occur after therapy has been discontinued.
Aminoglycosides possess a neuromuscular blocking action and
respiratory depression and muscular paralysis have been reported
and care is required when another neuromuscular blocking agent is
given concomitantly. Neurotoxicity has occurred, both peripheral
neuropathies and central symptoms including encephalopathy,
confusion, lethargy, hallucinations, convulsions and central
Cross-sensitivity may occur between aminoglycosides.
Hypersensitivity reactions, anaphylactic reactions and endotoxic
shock has been reported. Infrequent effects reported include blood
dyscrasias, purpura, nausea and vomiting, stomatitis, and signs of
liver dysfunction eg. increased serum aminotransferase values and
increased serum - bilirubin concentrations. Great care is required
in patients with myasthenia gravis, parkinsonism and other
conditions characterised by muscle weakness. It is desirable to
determine dosage requirements by individual monitoring. Dosage
should be adjusted to avoid peak plasma concentrations above 10 to
20 µg/mL, or trough concentrations exceeding 2 µg/ml. Monitoring is
important in patients receiving high doses or prolonged courses, in
infants and the elderly and in patients with renal failure.
Use of aminoglycosides during pregnancy may damage the 8th cranial
nerve of the foetus.
Some affected drugs include: amikacin, tobramycin, amphotericin B,
cidofovir, cisplatin, polymyxin B, cephalosporins such as
cephaloridine, nonsteroidal anti-inflammatory drugs (NSAIDs) such
as ibuprofen, "water pills"/diuretics such as furosemide, among
others. Although most antibiotics probably do not affect hormonal
birth control such as pills, patch, or ring, some antibiotics may
decrease their effectiveness.
Precautions & Warning:
Due to the risk of ototoxicity and neurotoxicity with prolonged use
of aminoglycosides, gentamicin must be restricted to the therapy of
life-threatening infections in which a less toxic antimicrobial
agent is not suitable. Serum peak levels of 10 µg/mL must be
avoided as this could be toxic. Serum trough levels of more than 2
µg/mL may be the best indication of accumulation of gentamicin
which may be associated with toxicity.
To ensure safe and effective therapy, dosages should be monitored
with serum peak and trough levels. Where practical, regular
determination of plasma creatinine levels is advised.
Toxic levels may be reached when gentamicin is administered in
normal doses to patients with impaired renal function.
Use in Pregnancy and Nursing Mothers:
Gentamicin injection is not recommended during pregnancy except in
life-threatening situations, even though studies in expectant
animals have not revealed teratogenic effects. Aminoglycoside
antibiotics cross the placenta, and there have been several reports
of total irreversible bilateral congenital deafness in children
whose mothers received streptomycin during pregnancy. Serious side
effects to mother, fetus, or newborn have not been reported in the
treatment of pregnant women with other aminoglycosides.
Treatment/antidote in The Event of Overdose:
In the event of overdose 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
Store below 25℃. Protect from moisture. Keep out of reach of