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Cidomycin Side Effects

Generic name: gentamicin

Medically reviewed by Last updated on Oct 24, 2022.

Note: This document contains side effect information about gentamicin. Some dosage forms listed on this page may not apply to the brand name Cidomycin.

Applies to gentamicin: injection solution.


Injection route (Solution)

Therapy has been associated with potential neurotoxicity, ototoxicity, and nephrotoxicity. Patients with impaired renal function, advanced age, dehydration, and those who receive high doses or prolonged therapy are at an increased risk of toxicity. Monitor renal and auditory function during therapy and discontinue therapy or adjust dose if there is evidence of ototoxicity or nephrotoxicity. Aminoglycoside-induced ototoxicity is usually irreversible. Serum concentrations of aminoglycosides should be monitored when feasible to assure adequate levels and to avoid potentially toxic levels. Concurrent use of other potentially neurotoxic or nephrotoxic agents, or potent diuretics should be avoided. Aminoglycosides can cause fetal harm when administered to a pregnant woman.

Serious side effects of Cidomycin

Along with its needed effects, gentamicin (the active ingredient contained in Cidomycin) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking gentamicin:

Incidence not known

  • Abdominal or stomach cramps or pain
  • agitation
  • back pain
  • black, tarry stools
  • blood in the urine
  • blurred or double vision
  • burning, numbness, tingling, or painful sensations
  • change in frequency of urination or amount of urine
  • chest pain
  • chills
  • coma
  • confusion
  • continuing ringing or buzzing or other unexplained noise in the ears
  • cough
  • difficult or troubled breathing
  • difficulty with swallowing
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • drowsiness
  • dry mouth
  • eye pain
  • fast heartbeat
  • fever with or without chills
  • hallucinations
  • headache
  • hearing loss
  • hives
  • hoarseness
  • increased thirst
  • irregular heartbeats
  • irregular, fast or slow, or shallow breathing
  • irritability
  • itching
  • joint pain
  • loss of appetite
  • mood or mental changes
  • muscle cramps in the hands, arms, feet, legs, or face
  • muscle pain or weakness
  • muscle spasms (tetany) or twitching
  • nausea or vomiting
  • nervousness
  • numbness and tingling around the mouth, fingertips, or feet
  • pale or blue lips, fingernails, or skin
  • pale skin
  • pinpoint red spots on the skin
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • right upper abdominal or stomach pain and fullness
  • seizures
  • sensation of spinning
  • skin rash
  • slow or fast heartbeat
  • slow or irregular breathing
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • stiff neck
  • sweating
  • swelling of the feet or lower legs
  • swollen glands
  • tightness in the chest
  • trembling
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • weight chest discomfort
  • weight loss
  • wheezing

Other side effects of Cidomycin

Some side effects of gentamicin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

  • Blurred or loss of vision
  • decreased appetite
  • depression
  • disturbed color perception
  • hair loss or thinning of the hair
  • halos around lights
  • hives or welts
  • increased salivation
  • night blindness
  • overbright appearance of lights
  • pain at the injection site
  • purple spots on the skin
  • redness of the skin
  • swelling or inflammation of the mouth
  • tunnel vision
  • unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness

For Healthcare Professionals

Applies to gentamicin: compounding powder, injectable solution, intravenous solution.


The most frequently reported adverse effects associated with treatment are ototoxicity and nephrotoxicity. These forms of toxicity occur more frequently in patients who experience prolonged exposure to serum trough concentrations of greater than 2 mcg/mL. Patients with renal insufficiency are at an increased risk of developing toxicity.[Ref]

Nervous system

Vestibular damage occurred more commonly when peak levels of 10 mcg/mL or trough levels of 2 mcg/mL were exceeded.[Ref]

Common (1% to 10%): Myasthenia gravis aggravated/unmasked, neuromuscular blockade

Very rare (less than 0.01%): Convulsion, encephalopathy, lethargy, peripheral paresthesia, polyneuropathy, vestibulocochlear nerve damage with potential involvement of the organ of balance/hearing

Frequency not reported: Central neurotoxicity, generalized burning, headache, lethargy, myasthenia gravis-like syndrome, numbness, peripheral neuropathy, pseudotumor cerebri, skin tingling, toxic neuropathy, vestibular damage[Ref]


Uncommon (0.1% to 1%): Nausea, stomatitis, vomiting

Rare (0.01% to 0.1%): Pseudomembranous colitis

Frequency not reported: Increased salivation[Ref]


Uncommon (0.1% to 1%): AST increased, ALT increased, blood bilirubin increased

Very rare (less than 0.01%): Alkaline phosphatase increased

Frequency not reported: Transient hepatomegaly[Ref]


Uncommon (0.1% to 1%): Blood dyscrasias

Very rare (less than 0.01%): Thrombocytopenia

Frequency not reported: Anemia, decreased reticulocyte counts, eosinophilia, granulocytopenia, increased reticulocyte counts, leukopenia, splenomegaly, transient agranulocytosis[Ref]


Rare (0.01% to 0.1%): Electrolyte disturbances, hypocalcemia, hypokalemia, hypomagnesemia

Frequency not reported: Decreased appetite, decreased serum calcium, decreased serum magnesium, decreased serum potassium, decreased serum sodium, hypovolemia, tetany, weight loss[Ref]


Very rare (less than 0.01%): Elevated serum creatinine, elevated serum urea, kidney damage, oliguria, reduction of glomerular filtration rate

Frequency not reported: Acute renal failure, blood urea nitrogen (BUN) increased, increased nonprotein nitrogen (NPN), nephrotoxicity[Ref]

Nephrotoxicity, demonstrated by the presence of casts, cells, protein in the urine, rising BUN, NPN, serum creatinine, and/or oliguria, was usually reversible with treatment withdrawal, and was more common in patients with preexisting renal dysfunction, those receiving concomitant treatment with other nephrotoxic agents, and trough serum concentrations above 2 mcg/mL.

Signs of kidney damage included cylindruria, hematuria, oliguria, proteinuria, and elevated serum creatinine and urea.[Ref]


Frequency not reported: Cells in urine, cylindruria, hematuria, proteinuria, urinary casts[Ref]


Very rare (less than 0.01%): Confusional state, depression/mental depression, hallucination

Frequency not reported: Acute organic brain syndrome, confusion[Ref]


Very rare (less than 0.01%): Ototoxicity, tinnitus

Frequency not reported: Diminishing high-tone acuity, extravasation, febrile response, fever, hearing loss, roaring in the ears[Ref]


Very rare (less than 0.01%): Pruritus, urticaria

Frequency not reported: Alopecia, itching, purpura, rash[Ref]


Very rare (less than 0.01%): Anaphylactic reaction

Frequency not reported: Anaphylactoid reaction, hypersensitivity[Ref]


Frequency not reported: Fat necrosis, injection site infection, injection site pain, local irritation, subcutaneous atrophy[Ref]


Frequency not reported: Hypertension, hypotension, phlebitis, venous thrombosis[Ref]


Frequency not reported: Laryngeal edema, postoperative respiratory distress, pulmonary fibrosis, respiratory depression[Ref]


Frequency not reported: Joint pain, muscle twitching, muscle weakness[Ref]


Frequency not reported: Visual disturbances[Ref]


Frequency not reported: Increased serum lactate dehydrogenase (LDH)[Ref]


1. "Product Information. Garamycin (gentamicin)." Schering-Plough Corporation (2007):

2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

3. Cerner Multum, Inc. "Australian Product Information." O 0

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.