Gentamicin Dosage

Usual Adult Dose for Bacteremia

1.5 to 2 mg/kg loading dose, followed by 1 to 1.7 mg/kg IV or IM every 8 hours or 5 to 7 mg/kg IV every 24 hours.
Duration: 14 days, depending on the site, nature and severity of the bacteremia. Limiting the duration of gentamicin therapy may help limit toxicity. Once the patient is stable for at least 48 hours, less toxic intravenous or oral antibiotic therapy may be considered according to microbiology sensitivity data.

Usual Adult Dose for Bacterial Endocarditis Prophylaxis

1.5 mg/kg (maximum 120 mg) IV or IM once within 30 minutes of starting the procedure. For high risk patients, in addition to gentamicin, ampicillin 2 g is given IV or IM 30 minutes prior to the procedure, followed by ampicillin 1 g IV/IM or amoxicillin 1 g orally 6 hours later. In penicillin-allergic patients, vancomycin 1 g is infused intravenously 1 to 2 hours prior to the procedure.

Usual Adult Dose for Bacterial Infection

1.5 to 2 mg/kg loading dose, followed by 1 to 1.7 mg/kg IV or IM every 8 hours, or 5 to 7 mg/kg IV every 24 hours.
Duration: 7 to 21 days, depending on the nature and severity of the infection. Limiting the duration of gentamicin therapy may help limit toxicity. Once the patient is stable for at least 48 hours, less toxic intravenous or oral antibiotic therapy may be considered according to microbiology sensitivity data.

Usual Adult Dose for Brucellosis

2 mg/kg loading dose, followed by 1.7 mg/kg IV or IM every 8 hours or 5 mg/kg IV every 24 hours.
Duration: Gentamicin should be continued for the first 2 to 3 weeks of antibiotic therapy. Oral doxycycline or sulfamethoxazole/trimethoprim should be continued for at least 6 weeks.

Usual Adult Dose for Burns - External

2 to 2.5 mg/kg loading dose, followed by 1.7 to 2 mg/kg IV every 8 hours
Duration: 10 to 14 days, depending on the nature and severity of the infection

Usual Adult Dose for Cystic Fibrosis

5 to 10 mg/kg/day in 2 to 4 divided doses
Duration: Parenteral therapy should be continued for about 14 to 21 days, depending on the nature and severity of the infection and improvement of pulmonary function.

Usual Adult Dose for Endocarditis

Native valve infections due to highly penicillin-susceptible viridans Group streptococci and S bovis (MIC <= 0.12 mcg/mL): 3 mg/kg IV or IM once every 24 hours in combination with aqueous penicillin G or ceftriaxone.
Duration: 2 weeks; continue other antibiotic for 4 weeks

Native valve infections due to relatively penicillin-resistant S viridans and S bovis (MIC > 0.12 mcg/mL and <+0.5 mcg/mL): 3 mg/kg IV or IM once every 24 hours in combination with aqueous penicillin G or ceftriaxone.
Duration: 2 weeks; continue other antibiotic for 4 weeks

Prosthetic valve infections due to S viridans and S bovis:
3 mg/kg IV or IM once every 24 hours in combination with aqueous penicillin G or ceftriaxone.
Duration: 2 weeks; continue other antibiotic for 6 weeks

Native valve infections due to staphylococci:
1.5 mg/kg IV or IM every 12 hours or 1 mg/kg every 8 hours, in combination with nafcillin, oxacillin, or cefazolin
Duration: 3 to 5 days; continue other antibiotic for 6 weeks

Prosthetic valve infections due to staphylococci:
1.5 mg/kg IV or IM every 12 hours or 1 mg/kg every 8 hours, in combination with nafcillin or oxacillin, plus rifampin, or vancomycin plus rifampin.
Duration: 2 weeks; continue other antibiotics for 6 weeks

Native valve or prosthetic valve infections due to susceptible enterococci:
1 mg/kg IV or IM every 8 hours, in combination with ampicillin, aqueous penicillin G, or vancomycin.
Duration: 4 to 6 weeks; continue other antibiotic for 6 weeks

Native valve or prosthetic valve infections due to penicillin-resistant enterococci:
1 mg/kg IV or IM every 8 hours, in combination with ampicillin-sulbactam or vancomycin.
Duration: 6 weeks

Refer to current published guidelines for detailed recommendations.

Usual Adult Dose for Endometritis

2 mg/kg loading dose, followed by 1.5 mg/kg IV or IM every 8 hours.
Duration: Parenteral therapy should be continued for at least 24 hours after the patient has remained afebrile, pain free, and the leukocyte count has normalized.

Usual Adult Dose for Febrile Neutropenia

2 mg/kg loading dose, followed by 1.7 mg/kg IV every 8 hours.
Duration: Once the patient is stable, afebrile for 24 hours, and the absolute neutrophil count is greater than 500/mm3, oral antibiotics may be substituted if antibiotic therapy is to be continued.

Usual Adult Dose for Intraabdominal Infection

2 mg/kg loading dose, followed by 1.7 mg/kg IV every 8 hours or 5 mg/kg IV every 24 hours
Duration: 14 days, depending on the nature and severity of the infection. Less toxic antibiotics may be substituted once the patient is stable for at least 48 hours.

Usual Adult Dose for Meningitis

Intravenous/Intramuscular: 2 mg/kg loading dose, followed by 1.7 mg/kg every 8 hours. Duration: Parenteral therapy should be continued for at least one week after the patient becomes afebrile and cerebrospinal fluid normalizes.

Usual Adult Dose for Osteomyelitis

1.5 to 2 mg/kg loading dose, followed by 1 to 1.7 mg/kg IV or IM every 8 hours or 5 to 7 mg/kg IV every 24 hours.
Duration: 4 to 6 weeks, depending on the nature and severity of the infection. Chronic osteomyelitis may require an additional 1 to 2 months of oral antibiotics. Limiting the duration of gentamicin therapy may help limit toxicity. Once the patient is stable for at least 48 hours, less toxic intravenous or oral antibiotic therapy may be considered according to microbiology sensitivity data.

Usual Adult Dose for Pelvic Inflammatory Disease

2 mg/kg loading dose, followed by 1.5 mg/kg IV or IM every 8 hours or 5 mg/kg IV every 24 hours.
Duration: Parenteral therapy should be continued for at least 24 hours after clinical improvement and should followed by oral doxycycline or clindamycin for a total 14 day course.

Usual Adult Dose for Peritonitis

IV: 2 mg/kg loading dose, followed by 1.7 mg/kg IV every 8 hours or 5 mg/kg IV every 24 hours.
Duration: Therapy should be continued for about 14 days, depending on the nature and severity of the infection. Limiting the duration of gentamicin therapy may help limit toxicity. Once the patient is stable for at least 48 hours, less toxic intravenous or oral antibiotic therapy may be considered according to microbiology sensitivity data.

Intraperitoneally in CAPD patients: 0.6 to 0.75 mg/kg intraperitoneally once daily or 16 to 20 mg per every 2 L dialysate.

Usual Adult Dose for Plague

2 mg/kg loading dose, followed by 1.7 mg/kg IV or IM every 8 hours or 5 mg/kg IV every 24 hours.
Duration: Therapy should be continued for about 10 to 14 days, depending on the nature and severity of the infection. Limiting the duration of gentamicin therapy may help limit toxicity. Once the patient's condition improves, less toxic intravenous or oral antibiotic therapy may be considered according to microbiology sensitivity data.

Usual Adult Dose for Pneumonia

2 mg/kg loading dose, followed by 1.7 mg/kg IV or IM every 8 hours or 5 mg/kg IV every 24 hours.
Duration: Therapy should be continued for 14 to 21 days, depending on the nature and severity of the infection. Limiting the duration of gentamicin therapy may help limit toxicity. Once the patient is stable for at least 48 hours, less toxic intravenous or oral antibiotic therapy may be considered according to microbiology sensitivity data.

Usual Adult Dose for Pyelonephritis

2 mg/kg loading dose, followed by 1.7 mg/kg IV every 8 hours or 5 mg/kg IV every 24 hours.
Duration: Therapy should be continued for about 7 to 14 days, depending on the nature and severity of the infection. Limiting the duration of gentamicin therapy may help limit toxicity. Once the patient is stable for at least 48 hours, less toxic intravenous or oral antibiotic therapy may be considered according to microbiology sensitivity data.

Usual Adult Dose for Skin or Soft Tissue Infection

1.5 to 2 mg/kg loading dose, followed by 1 to 1.7 mg/kg IV or IM every 8 hours or 5 to 7 mg/kg IV every 24 hours.
Duration: Therapy should be continued for at least 10 to 14 days, or until 3 days post acute inflammation, depending on the nature and severity of the infection. For severe infections, such as diabetic soft tissue infections, 14 to 21 days of therapy may be required. Limiting the duration of gentamicin therapy may help limit toxicity. Once the patient is stable for at least 48 hours, less toxic intravenous or oral antibiotic therapy may be considered according to microbiology sensitivity data.

Usual Adult Dose for Surgical Prophylaxis

1.5 to 2 mg/kg (maximum 120 mg) IV or IM once at induction of anesthesia

Usual Adult Dose for Tularemia

1.5 to 2 mg/kg loading dose, followed by 1 to 1.7 mg/kg IV or IM every 8 hours or 5 to 7 mg/kg IV every 24 hours.
Duration: Therapy should be continued for about 10 to 14 days, depending on the nature and severity of the infection. Once the patient's condition improves, less toxic intravenous or oral antibiotic therapy may be considered according to microbiology sensitivity data.

Usual Pediatric Dose for Bacterial Infection

0 to 4 weeks, birthweight <1200 g: 2.5 mg/kg IV or IM every 18 to 24 hours

0 to 1 week, birthweight >=1200 g: 2.5 mg/kg IV or IM every 12 hours

1 to 4 weeks, birthweight 1200 to 2000 g: 2.5 mg/kg IV or IM every 8 to 12 hours

1 to 4 weeks, birthweight >=2000 g: 2.5 mg/kg IV or IM every 8 hours

>1 month: 1 to 2.5 mg/kg IV or IM every 8 hours

Usual Pediatric Dose for Bacterial Endocarditis Prophylaxis

1.5 mg/kg IV or IM once within 30 minutes of starting the procedure. For high risk patients, in addition to gentamicin, ampicillin 50 mg/kg (maximum 2 G) is given IV or IM 30 minutes prior to the procedure, followed by ampicillin 25 mg/kg IV/IM or amoxicillin 25 mg/kg orally 6 hours later. In penicillin-allergic patients, vancomycin 20 mg/kg IV is infused over 1 to 2 hours instead of ampicillin/amoxicillin.

Usual Pediatric Dose for Endocarditis

Native valve infections due to highly penicillin-susceptible viridans Group streptococci and S bovis (MIC <= 0.12 mcg/mL): 3 mg/kg IV or IM once every 24 hours or 1 mg/kg every 8 hours in combination with aqueous penicillin G or ceftriaxone.
Duration: 2 weeks; continue other antibiotic for 4 weeks

Native valve infections due to relatively penicillin-resistant S viridans and S bovis (MIC > 0.12 mcg/mL and <+0.5 mcg/mL): 3 mg/kg IV or IM once every 24 hours or 1 mg/kg every 8 hours in combination with aqueous penicillin G or ceftriaxone.
Duration: 2 weeks; continue other antibiotic for 4 weeks

Prosthetic valve infections due to S viridans and S bovis:
3 mg/kg IV or IM once every 24 hours or 1 mg/kg every 8 hours in combination with aqueous penicillin G or ceftriaxone.
Duration: 2 weeks; continue other antibiotic for 6 weeks

Native valve infections due to staphylococci:
1 mg/kg every 8 hours, in combination with nafcillin, oxacillin, or cefazolin
Duration: 3 to 5 days; continue other antibiotic for 6 weeks

Prosthetic valve infections due to staphylococci:
1 mg/kg every 8 hours, in combination with nafcillin or oxacillin, plus rifampin, or vancomycin plus rifampin.
Duration: 2 weeks; continue other antibiotics for 6 weeks

Native valve or prosthetic valve infections due to susceptible enterococci:
1 mg/kg IV or IM every 8 hours, in combination with ampicillin, aqueous penicillin G, or vancomycin.
Duration: 4 to 6 weeks; continue other antibiotic for 6 weeks

Native valve or prosthetic valve infections due to penicillin-resistant enterococci:
1 mg/kg IV or IM every 8 hours, in combination with ampicillin-sulbactam or vancomycin.
Duration: 6 weeks

Refer to current published guidelines for detailed recommendations.

Usual Pediatric Dose for Surgical Prophylaxis

2 mg/kg IV once at induction of anesthesia

Renal Dose Adjustments

Parenteral:
Dosage should be adjusted in renal insufficiency. Various nomograms and methods have been proposed for determining the dosage in renally impaired adult patients - reduced doses at fixed intervals or normal doses at prolonged intervals. Regimens are ideally based on individualized pharmacokinetic dosing.

Adults:
The following adjustments to the maintenance dose have been suggested (modified from Sarubbi and Hull, 1978):
CrCl 70 to 80 mL/min: 76% to 91% of the loading dose every 8 to 12 hours
CrCl 60 to 70 mL/min: 71% to 88% of the loading dose every 8 to 12 hours
CrCl 50 to 60 mL/min: 65% to 84% of the loading dose every 8 to 12 hours
CrCl 40 to 50 mL/min: 72% to 92% of the loading dose every 12 to 24 hours
CrCl 30 to 40 mL/min: 63% to 92% of the loading dose every 12 to 24 hours
CrCl 20 to 30 mL/min: 50% to 81% of the loading dose every 12 to 24 hours
CrCl 10 to 20 mL/min: 34% to 75% of the loading dose every 12 to 24 hours
CrCl<10 mL/min: 21% to 47% of the loading dose every 24 hours or a onetime loading dose with subsequent doses based on serum concentrations, estimated clearance and the patient's condition.

Adults, extended-interval dosing (dose and interval adjustment):
CrCl >80 mL/min: 5 to 7 mg/kg every 24 hours
CrCl 60 to 70 mL/min: 4 to 5.5 mg/kg every 24 hours
CrCl 50 mL/min: 3.5 to 5 mg/kg every 24 hours
CrCl 30 to 40 mL/min: 2.5 to 3.5 mg/kg every 24 hours
CrCl 20 mL/min: 4 to 5 mg/kg every 48 hours
CrCl 10 mL/min: 3 to 4 mg/kg every 48 hours

Adults, extended-interval dosing (constant dose with interval adjustment):
CrCl > 60 mL/min: 7 mg/kg every 24 hours
CrCl 40 to 60 mL/min: 7 mg/kg every 36 hours
CrCl 20 to 40 mL/min: 7 mg/kg every 48 hours; monitor serum levels
CrCl <20 mL/min: 7 mg/kg once; repeat when trough level < 1 mcg/mL


Inhalation:
If nephrotoxicity is suspected, therapy should be discontinued until gentamicin serum concentrations fall below 2 mcg/mL.

Liver Dose Adjustments

No adjustment recommended

Dose Adjustments

In obese patients, the appropriate parenteral dose may be calculated by using the estimated lean body weight plus 40% of the excess as the basic weight on which to figure mg/kg.

Precautions

It is desirable to limit the duration of treatment with aminoglycosides to short term. To prevent increased toxicity due to excessive blood levels, dosage should not exceed 5 mg/kg/day unless serum levels are monitored. With treatment >10 days, monitoring of renal, auditory, and vestibular functions is recommended.

In patients with extensive burns, altered pharmacokinetics may result in reduced serum levels of aminoglycosides. In such patients treated with gentamicin, measurement of serum levels is recommended as a basis for dosage adjustment.

Dialysis

Gentamicin is 30% removed during hemodialysis. The dose should be administered following dialysis.

Hemodialysis and peritoneal dialysis: Onetime loading dose, with subsequent doses based on serum concentrations, estimated clearance and the patient's condition.

or 2 to 4 mg/kg every 48 hours

Other Comments

It is desirable to measure periodically both peak and trough serum levels of gentamicin when feasible during therapy to assure adequate but not excessive drug levels. When monitoring peak levels after IM or IV administration, dosage should be adjusted so that prolonged levels >12 mcg/mL are avoided. When monitoring trough levels (just prior to the next dose), dosage should be adjusted so that levels >2 mcg/mL are avoided. The usual duration of treatment for all patients is 7 to 10 days. In difficult and complicated infections, a longer course of therapy may be necessary.

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