Tobramycin serum levels and tissue content in children
Related Experiment Videos
Insights
Tobramycin levels were measured in children after injection. Fat tissue showed higher tobramycin concentrations than muscle tissue, suggesting blood supply isn't the primary factor influencing drug distribution.
Area of Science:
- Pharmacology
- Pediatric Medicine
- Clinical Pharmacy
Background:
- Tobramycin is an aminoglycoside antibiotic used to treat bacterial infections.
- Understanding tobramycin distribution in pediatric tissues is crucial for optimizing dosage and efficacy.
- Previous studies have not fully elucidated tobramycin's tissue penetration in children.
Purpose of the Study:
- To determine tobramycin serum and tissue concentrations in children following intramuscular administration.
- To compare tobramycin levels in muscle, fat, spleen, and testis.
- To investigate factors influencing tobramycin tissue distribution.
Main Methods:
- A single intramuscular injection of tobramycin (2.5 mg/kg) was administered to 29 children.
- Serum, muscle, fat, spleen, and testis samples were collected hourly for 8 hours.
- Tobramycin concentrations were quantified using an agar diffusion method.
- Tissue fluid was obtained using a Colworth Stomacher.
Main Results:
- Peak serum tobramycin concentration (4.32 µg/ml) occurred at 1.5 hours, followed by a decline.
- Mean peak concentrations in muscle (0.93 µg/g) and fat (1.16 µg/g) were observed at 1.5 hours.
- Tobramycin levels in fat tissue were significantly higher (24% of serum) than in muscle tissue (17% of serum).
- Spleen and testis tobramycin content did not exceed levels found in muscle or fat.
- By 8 hours, tissue tobramycin levels fell below the limit of detection (0.01 µg/g).
Conclusions:
- Tobramycin distribution varies between tissues in children, with fat tissue accumulating higher concentrations than muscle.
- Tissue blood supply does not appear to be the primary determinant of tobramycin content in various tissues.
- These findings have implications for understanding tobramycin pharmacokinetics and guiding therapeutic strategies in pediatric populations.
Abstract:
Tobramycin serum levels as well as muscle and fat tissue content have been determined for 8 h in hourly intervals using an agar diffusion method following a single intramuscular injection of 2.5 mg/kg body weight to 29 children. In addition two specimens of spleen and one testis could be assayed for tobramycin content in these children. Tissue fluid was obtained by use of a Colworth Stomacher Nr.80. At 1 1/2 hours mean peak concentrations in serum were found to be 4.32 microgram/ml, in muscle 0.93 microgram/g and in fat 1.16 microgram/g, from thereon declining to lower values. At 8 h tissue content fell below the smallest detectable amount of 0.01 microgram/g tobramycin. At any time tobramycin content in fat (on average 24% of the corresponding serum level) was significantly higher than in muscle (17% of the serum level), whereas tobramycin content in spleen never exceeded that in muscle as well as in fat. Thus blood supply of the tissue does not seem to the main factor determining tobramycin content in various tissues.