EFFECT OF PHONOPHORESIS WITH DEXAMETHASONE ON ADRENAL-FUNCTION

One of the side effects of corticosteroid ingestion and inhalants is s uppression of the adrenal glands. Phonophoresis of topically applied c orticosteroids is commonly used to treat musculoskeletal inflammatory conditions. The purpose of this study was to determine whether phonoph oresis with dexamethasone sodium phosphate affected adrenal function. The subjects included 28 male volunteers (($) over bar X = 25.3 years, SD = 6.4) who received phonophoresis to the left shoulder every other day for 2 weeks. Subjects were randomly assigned to one of four group s, including a control group (N = 8), an ultrasound group (N = 8), a . 33% dexamethasone group (N = 7), and a ultrasound with .33% dexamethas one group (N = 5). Adrenal function was assessed by 24-hour urinary-fr ee cortisol (mu g Cortisol/g creatinine) collected two days prior to a nd following the phonophoresis treatments. A nonparametric analysis of variance using a split plot factorial design was calculated for ranke d urinary-free cortisol scores and found no significant (p > 0.05) dif ferences in urinary-free cortisol levels between the four groups and b etween the four collection days, and there were no significant (P > 0. 05) interactions exhibited between group and collection day. This stud y suggests that phonophoresis with dexamethasone sodium phosphate, usi ng common clinical parameters, does not cause dexamethasone sodium pho sphate to become systemic in large enough quantities to impair adrenal function.