Serum dexamethasone levels after decadron phonophoresis.

OBJECTIVE

To determine serum levels of dexamethasone at several intervals after administration of Decadron (dexamethasone sodium phosphate) phonophoresis.

DESIGN AND SETTING

This study was designed as a 2-factor analysis of variance with repeated measures on 1 factor (blood draws). Independent variables were group (gel/sham, gel/ ultrasound, dexamethasone/sham, dexamethasone/ultrasound) and blood draws (pretreatment, posttreatment, 15 minutes, and 30 minutes). The dependent variable was the serum level of dexamethasone.

SUBJECTS

Forty healthy college students (21 males, 19 females; mean age = 22 +/- 1.3 years) with no known drug allergies or current medication use were randomly assigned to 1 of 4 treatment groups. The treatment site was the left forearm.

MEASUREMENTS

After the pretreatment blood draw, a 10- minute ultrasound treatment was administered, followed by a posttreatment blood draw. Two additional blood draws followed at 15-minute intervals. A total of 4 serum samples (5 cc each) from each subject were centrifuged, and the pipetted serum was frozen for later analysis by double antibody radioimmunoassay.

RESULTS

No significant amounts of serum dexamethasone were detected in 12 consecutive samples. Testing of additional samples was, therefore, discontinued.

CONCLUSIONS

Decadron phonophoresis as used in this experiment did not result in detectable serum levels of dexamethasone. More study is needed to validate the efficacy of Decadron phonophoresis on serum dexamethasone levels.