General Information

Cayston contains the active ingredient aztreonam, a monobactam antibacterial. Aztreonam exhibits activity in vitro against Gram-negative aerobic pathogens including P. aeruginosa. Aztreonam binds to penicillin binding proteins of susceptible bacteria, which leads to inhibition of bacterial cell wall synthesis and death of the cell.

Cayston is specifically indicated to improve respiratory symptoms in cystic fibrosis patients with Pseudomonas aeruginosa.

Cayston is supplied as a single-use vial of sterile, lyophilized aztreonam to be reconstituted with a 1 mL ampule of sterile diluent designed for administration via inhalation using an Altera Nebulizer System.. The recommended dose of Cayston for both adults and pediatrics 7 years of age and older is one single-use vial (75 mg of aztreonam) reconstituted with 1 mL of sterile diluent administered 3 times a day for a 28-day course (followed by 28 days off Cayston therapy). Dosage is not based on weight or adjusted for age. Doses should be taken at least 4 hours apart.

Mechanism of Action

Cayston contains the active ingredient aztreonam, a monobactam antibacterial. Aztreonam exhibits activity in vitro against Gram-negative aerobic pathogens including P. aeruginosa. Aztreonam binds to penicillin binding proteins of susceptible bacteria, which leads to inhibition of bacterial cell wall synthesis and death of the cell.

Side Effects

Adverse events associated with the use of Cayston may include, but are not limited to, the following:

• Cough
• Nasal congestion
• Wheezing
• Pharyngolaryngeal pain
• Chest discomfort
• Pyrexia
• Abdominal Pain
• Vomiting

Clinical Trial Results

The FDA approval of Cayston was based on a randomized, double-blind, placebo-controlled, multicenter trial in 164 subjects. The subjects received either Cayston (75 mg) or volume-matched placebo administered by inhalation 3 times a day for 28 days. Patients were required to have been off antibiotics for at least 28 days before treatment with study drug. The primary efficacy endpoint was improvement in respiratory symptoms on the last day of treatment with Cayston or placebo. Statistically significant improvements were seen in both adult and pediatric patients, but were substantially smaller in adult patients. The treatment difference at Day 28 between Cayston-treated and placebo-treated patients for percent change in FEV1 (L) was statistically significant at 10%. Improvements in FEV1 were comparable between adult and pediatric patients. Two weeks after completion of drug treatment, the difference in FEV1 between Cayston and placebo groups had decreased to 6%.