What is the regimen for nebulized tobramycin (Tobramycin) inhalation solution?

From the Guidelines

The standard regimen for nebulized tobramycin in patients with cystic fibrosis or bronchiectasis is 300 mg administered twice daily (every 12 hours) in alternating cycles of 28 days on treatment followed by 28 days off treatment, as recommended by the most recent guidelines 1. This regimen is based on the evidence from the American Journal of Respiratory and Critical Care Medicine, which suggests that inhaled tobramycin is effective in improving lung function and quality of life, and reducing exacerbations in patients with moderate to severe lung disease and Pseudomonas aeruginosa infections 1. The solution should be administered using an appropriate nebulizer device, and patients should use bronchodilators if prescribed, and perform airway clearance techniques to optimize drug deposition. Common side effects include voice alteration, tinnitus, and bronchospasm, and monitoring should include baseline and periodic audiometry and renal function tests. Tobramycin works by binding to bacterial ribosomes, inhibiting protein synthesis and ultimately killing susceptible bacteria, particularly Pseudomonas aeruginosa, which is a common pathogen in these respiratory conditions. It's worth noting that the European Respiratory Journal also provides guidance on the use of nebulized tobramycin, suggesting that 300 mg twice daily on alternative months is safe over a two-year period, and that resistance to tobramycin may develop but does not seem to be clinically important 1. However, the most recent and highest quality study 1 provides the strongest evidence for the recommended regimen. Some key points to consider when administering nebulized tobramycin include:

• Using an appropriate nebulizer device
• Administering the solution in alternating cycles of 28 days on treatment followed by 28 days off treatment
• Monitoring for common side effects such as voice alteration, tinnitus, and bronchospasm
• Performing baseline and periodic audiometry and renal function tests
• Optimizing drug deposition through the use of bronchodilators and airway clearance techniques.

From the FDA Drug Label

Under standardized in vitro testing at a fixed flow rate of 60 L/min and volume of 2 L for 2 seconds, the Podhaler device has a target delivered dose of 102 mg of tobramycin from the mouthpiece (4 capsules per dose).

The regimen for nebulised tobramycin is 112 mg twice-daily, with each dose consisting of 4 capsules of 28 mg each, administered using the Podhaler device 2.

From the Research

Regimen for Nebulised Tobramycin

• The optimal therapeutic regimen and duration for early treatment of Pseudomonas aeruginosa infection in patients with cystic fibrosis remains unclear 3.
• A study found that treatment with tobramycin inhalation solution (TIS) for 28 days is an effective and well-tolerated therapy for early P aeruginosa infection in patients with cystic fibrosis 3.
• The study compared two regimens of TIS (28 and 56 days) and found that the median time to recurrence of P aeruginosa was similar between the two groups 3.
• Another study compared the efficacy of tobramycin inhalation powder (TIP) with nebulized TIS and found that TIP had non-inferior efficacy and was generally well-tolerated, with a similar safety profile to TIS, except for a higher incidence of cough 4.
• A review of tobramycin safety and efficacy found that both TIS and TIP treatment regimens have demonstrated positive clinical outcomes in efficacy and safety, including improvements in FEV1, decreased sputum P. aeruginosa density, and reduced rates of hospitalizations due to respiratory events 5.
• The review also noted that TIS may be suitable for younger patients or those with low FEV1, while TIP may be more suitable for patients with less time to commit to their self-care 5.
• An early study on the use of tobramycin in patients with cystic fibrosis found that intravenous tobramycin was effective in treating Pseudomonas aeruginosa infections, with clinical and radiological improvement noted in all patients 6.
• However, this study did not investigate the use of nebulised tobramycin, and its findings may not be directly applicable to the current question.
• Other studies have investigated the use of alternative treatments, such as colistimethate sodium dry powder for inhalation, which has been found to be non-inferior to nebulized tobramycin in treating chronic Pseudomonas aeruginosa infections in patients with cystic fibrosis 7.

Dosage and Administration

• The ELITE study used a dosage of 300 mg/5 ml of TIS, administered twice daily via a jet nebuliser 3.
• The study comparing TIP with nebulized TIS used a dosage of 112 mg of TIP, administered twice daily via a dry powder inhaler 4.
• The review of tobramycin safety and efficacy noted that the recommended dosage of TIS is 300 mg/5 ml, administered twice daily via a nebuliser 5.