What is the recommended dosing for intravenous (IV) gentamicin for adults with pneumonia?

From the Guidelines

For adults with pneumonia, the recommended dosing for intravenous (IV) gentamicin is typically 5-7 mg/kg once daily for patients with normal renal function, as stated in the 2016 clinical practice guidelines by the Infectious Diseases Society of America and the American Thoracic Society 1. This once-daily dosing regimen is preferred over traditional multiple daily dosing due to improved efficacy and potentially reduced toxicity. The exact dose should be calculated based on the patient's ideal body weight or adjusted body weight for obese patients. Therapeutic drug monitoring is essential when using gentamicin, with peak levels drawn 30 minutes after infusion completion and trough levels obtained just before the next dose. Target peak concentrations should be 15-20 mcg/mL, while trough levels should be less than 1 mcg/mL for once-daily dosing, as supported by the Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016 1. Dose adjustments are necessary for patients with renal impairment, with either reduced doses or extended intervals. Gentamicin is typically used in combination with other antibiotics for pneumonia treatment, as it provides coverage against gram-negative organisms including Pseudomonas aeruginosa. Some key points to consider when dosing gentamicin include:

• Using a full, high end-loading dose of each agent used, as stated in the Surviving Sepsis Campaign guidelines 1
• Optimizing peak drug plasma concentrations for aminoglycosides and fluoroquinolones
• Ensuring that trough concentrations are sufficiently low to minimize the potential for renal toxicity
• Adjusting doses based on renal function and therapeutic drug monitoring results. The duration of therapy depends on clinical response but is generally limited to 5-7 days when possible to minimize nephrotoxicity and ototoxicity risks.

From the FDA Drug Label

This dosage should be reduced to 3 mg/kg/day as soon as clinically indicated TABLE 3 DOSAGE SCHEDULE GUIDE FOR ADULTS WITH NORMAL RENAL FUNCTION (Dosage at Eight-Hour Intervals) 1 mg/kg q8h (3 mg/kg/day) Dose for Serious Infections 1.7 mg/kg q8h** (5 mg/kg/day) Dose for Life-Threatening Infections (Reduce As Soon As Clinically Indicated)

The recommended dosing for intravenous (IV) gentamicin for adults with pneumonia is:

• Serious infections: 1 mg/kg every 8 hours (3 mg/kg/day)
• Life-threatening infections: 1.7 mg/kg every 8 hours (5 mg/kg/day), reduce to 3 mg/kg/day as soon as clinically indicated 2 Key points to consider:
• Dosage adjustment: may be necessary based on serum concentrations, renal function, and patient's response to treatment
• Monitoring: peak and trough serum concentrations should be measured periodically during therapy to assure adequate but not excessive drug levels 2

From the Research

Recommended Dosing for IV Gentamicin in Adults with Pneumonia

The recommended dosing for intravenous (IV) gentamicin in adults with pneumonia can vary depending on several factors, including the severity of the infection, renal function, and the presence of other underlying medical conditions.

• The initial dose of gentamicin in critically ill hyperdynamic septic patients should be 7 mg/kg, as recommended by a study published in 2001 3.
• A once-daily dosage regimen of gentamicin is considered feasible in critically ill patients, with a trend towards using higher loading doses (5-7 mg/kg) observed in the USA 3.
• The treatment period with gentamicin should be short (3-5 days), taking into account the pharmacological properties of aminoglycosides, such as small volume of distribution and poor tissue penetration 3.
• In patients with reduced renal function, the initial dose of gentamicin should also be increased, and the maintenance dose reduced preferentially by prolonging the dosing intervals 3.

Comparison of Once-Daily and Thrice-Daily Dosing Regimens

A study published in 1995 compared the efficacy and safety of IV gentamicin administered once daily versus thrice daily in adults 4.

• The results showed that the once-daily dosing regimen was more effective and less ototoxic than the thrice-daily regimen.
• The mean peak level of gentamicin in the once-daily group was significantly higher than that in the thrice-daily group, while the trough level was lower.

Safety and Efficacy of Gentamicin in Severe Community-Acquired Pneumonia

A retrospective cohort study published in 2018 assessed the safety and efficacy of gentamicin for empirical Gram-negative coverage of severe community-acquired pneumonia (CAP) in patients admitted to the ICU 5.

• The results showed that gentamicin was safe and had similar outcomes to alternative Gram-negative antimicrobial regimens for empirical coverage in severe CAP patients.
• There were no significant differences between the gentamicin and no-gentamicin groups in terms of incidence of acute kidney injury, hospital mortality, and secondary outcomes, including relapse and length of hospital stay.