This site is intended for US healthcare professionals only.
Home/Clinical Benefits/Pharmacokinetics
BETHKIS® (Tobramycin Inhalation Solution)
Concentrated in airways
Adapted from data on file.
- 30 minutes after inhalation, in patients treated with BETHKIS, high variability of tobramycin concentration in sputum was observed (maximum geometric mean Cmax concentration of 814 µg/g, ranging from 23 to 2843 µg/g)2,3
- Following inhalation of BETHKIS, 89% of patients demonstrated peak concentrations of tobramycin in sputum >25 times the parenteral tobramycin breakpoint of 16 µg/mL3,4
- Aminoglycosides may aggravate muscle weakness because of a potential curare-like effect on neuromuscular function
- Pharmacokinetic data do not directly relate to clinical efficacy
Limited systemic exposure
Adapted from Poli et al. Pediatr Drugs. 2007:9(suppl 1):3-9.
The graph above demonstrates results from a study to compare in vitro characteristics and pharmacokinetics of Bramitob® (marketed as BETHKIS 300 mg/4 mL in the United States) and Tobi® in patients with cystic fibrosis (CF) and P aeruginosa infection. In the randomized, double-blind, two-way crossover pharmacokinetic study, 9 patients with CF received a single nebulized dose (300 mg) of Bramitob or Tobi separated by a 7-day washout period. Plasma and sputum concentrations were measured immediately before and over 24 hours after administration.2
- The elimination half-life of BETHKIS is approximately 4.4 hours3
Important Safety Information
BETHKIS® (Tobramycin Inhalation Solution) is contraindicated in patients with a known hypersensitivity to any aminoglycoside.
Bronchospasm can occur with inhalation of BETHKIS. Bronchospasm and wheezing should be treated as medically appropriate.
Caution should be exercised when prescribing BETHKIS to patients with known or suspected auditory, vestibular, renal, or neuromuscular dysfunction. Audiograms, serum concentration, and renal function should be monitored as appropriate.
Avoid concurrent and/or sequential use of BETHKIS with other drugs with neurotoxic or ototoxic potential.
BETHKIS should not be administered concurrently with ethacrynic acid, furosemide, urea, or mannitol.
Aminoglycosides may aggravate muscle weakness because of a potential curare-like effect on neuromuscular function.
Fetal harm can occur when aminoglycosides are administered to a pregnant woman. Apprise women of the potential hazard to the fetus.
Common adverse reactions (more than 5%) occurring more frequently in BETHKIS patients are forced expiratory volume decreased, rales, red blood cell sedimentation rate increased, and dysphonia.
Indication
BETHKIS is indicated for the management of cystic fibrosis patients with Pseudomonas aeruginosa. Safety and efficacy have not been demonstrated in patients under the age of six years, patients with FEV1 less than 40% or greater than 80% predicted, or patients colonized with Burkholderia cepacia.
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.
This website is intended for United States residents only.
References: 1. Data on file. Chiesi, Inc. 2. Poli G, Acerbi D, Pennini R, et al. Clinical pharmacology study of Bramitob®, a tobramycin solution for nebulization, in comparison with Tobi®. Pediatr Drugs. 2007;9(suppl 1):3-9. 3. BETHKIS [package insert]. Cary, NC: Chiesi, Inc.; 2017. 4. LiPuma JJ. Microbiological and immunologic considerations with aerosolized drug delivery. Chest. 2001;120(3 suppl):1185-1235.
