Gentamicin (Systemic)

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

• If your symptoms or health problems do not get better or if they become worse, call your doctor.
• Do not share your drugs with others and do not take anyone else's drugs.
• Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
• Talk with the doctor before starting any new drug, including prescription or OTC, natural products, or vitamins.
• Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about gentamicin, please talk with your doctor, nurse, pharmacist, or other health care provider.
• If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about gentamicin (systemic). It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using gentamicin.

Review Date: October 4, 2017

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• Antibiotic, Aminoglycoside

Hypersensitivity to gentamicin, other aminoglycosides, or any component of the formulation

Note: Dosage should be based on an estimate of ideal body weight. In morbidly obese children and adolescents, dosage requirement may best be estimated using a dosing weight of IBW + 0.4 (TBW - IBW). Dosage should be individualized based upon serum concentration monitoring. Initial and periodic plasma drug concentrations (eg, peak and trough with conventional dosing, post dose level at a prespecified time with extended-interval dosing) should be determined, particularly in critically ill patients with serious infections or in disease states known to significantly alter aminoglycoside pharmacokinetics (eg, cystic fibrosis, burns, or major surgery). Some dosing based on gentamicin studies:

General dosing, susceptible infection:

Conventional dosing:

Manufacturer's labeling:

Infants: IM, IV: 2.5 mg/kg/dose every 8 hours

Children and Adolescents: IM, IV: 2 to 2.5 mg/kg/dose every 8 hours

Alternate dosing: Infants, Children, and Adolescents: IM, IV: 2 to 2.5 mg/kg/dose every 8 hours; some pediatric patients may require larger doses (ie, patients undergoing continuous hemofiltration, patients with major burns, febrile granulocytopenic patients); modify dose based on individual patient requirements as determined by renal function, serum drug concentrations, and patient-specific clinical parameters (Red Book [AAP 2015])

Extended-interval dosing: Limited data available:

Weight-directed: Infants, Children, and Adolescents: IV: 4.5 to 7.5 mg/kg/dose every 24 hours in patients with normal renal function (Contopoulos-Ioannidis 2004; Red Book (AAP 2015])

Age-directed: Based on data from 114 patients, the following has been suggested (McDade 2010):

Infants and Children ≥3 months to <2 years: IV: 9.5 mg/kg/dose every 24 hours

Children 2 to <8 years: IV: 8.5 mg/kg/dose every 24 hours

Children ≥8 years and Adolescents: IV: 7 mg/kg/dose every 24 hours

Surgical (preoperative) prophylaxis (off-label use): Infants, Children, and Adolescents: IV: 2 to 2.5 mg/kg as a single dose; in children and adolescents, a dose of 2.5 mg/kg is typically suggested; administer within 60 minutes prior to surgical incision with or without other antibiotics (procedure dependent) (Bratzler 2013; Red Book [AAP 2015]).

There are no dosage adjustments provided in the manufacturer’s labeling; however dosage adjustment is not likely to be necessary (does not undergo hepatic metabolism).

IM: Administer by deep IM route if possible.

IV: Infuse over 30 to 120 minutes.

Some penicillins (eg, carbenicillin, ticarcillin, and piperacillin) have been shown to inactivate aminoglycosides in vitro. This has been observed to a greater extent with tobramycin and gentamicin, while amikacin has shown greater stability against inactivation. Concurrent use of these agents may pose a risk of reduced antibacterial efficacy in vivo, particularly in the setting of profound renal impairment. However, definitive clinical evidence is lacking. If combination penicillin/aminoglycoside therapy is desired in a patient with renal dysfunction, separation of doses (if feasible), and routine monitoring of aminoglycoside levels, CBC, and clinical response should be considered.

Urinalysis, urine output, BUN, serum creatinine, plasma gentamicin levels (as appropriate to dosing method). Levels are typically obtained before and after the third dose in conventional dosing. Hearing should be tested before, during, and after treatment; particularly in those at risk for ototoxicity or who will be receiving prolonged therapy (>2 weeks)

Some penicillin derivatives may accelerate the degradation of aminoglycosides in vitro. This may be clinically-significant for certain penicillin (ticarcillin, piperacillin, carbenicillin) and aminoglycoside (gentamicin, tobramycin) combination therapy in patients with significant renal impairment. Close monitoring of aminoglycoside levels is warranted.