Basal and post-ACTH cortisol levels in preterm infants following treatment with dexamethasone.
Dexamethasone (DEX) has been shown to decrease ventilator dependence in bronchopulmonary dysplasia (bronchopulmonary dysplasia). Abnormal metapyrone tests have been reported in 50% of infants who were weaned from a 45-day course of dexamethasone. We postulated that such infants would have adrenal suppression and would not respond to Cosyntropin (ACTH). We examined morning cortisol levels in 14 premature infants who had been treated with dexamethasone for 36 +/- 4 (mean +/- SEM) days, starting at 38 +/- 6 days of life, and performed ACTH stimulation tests in 12 of them. Morning cortisol levels were 87 +/- 36 nmol/L (range undetectable: 543; n = 14). Random basal cortisol levels were 109 +/- 42 nmol/L (range 34-540; n = 12). The mean cortisol level was 568 +/- 63 nmol/L (range 117-934) 60 min after adrenocorticotrophic hormone. In all cases, cortisol level increased three-fold after adrenocorticotrophic hormone. Low cortisol levels are almost universal in infants after treatment with dexamethasone, but the adrenal gland remains responsive to adrenocorticotrophic hormone stimulation. We speculate that dexamethasone causes secondary adrenal suppression at the hypothalamic-pituitary level. Normal adrenal function in the preterm infant needs to be defined.
Section of Neonatology, St. Boniface General Hospital, Winnipeg, Manitoba.
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Cronin
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Dean
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MacDonald
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Seshia
D000311:Adrenal Glands / Q000187:drug effects / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000378:metabolism / Q000494:pharmacology*; D001724:Birth Weight; D001997:Bronchopulmonary Dysplasia / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology; D002940:Circadian Rhythm / Q000502:physiology; D003907:Dexamethasone / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood*; D008297:Male; D013268:Stimulation, Chemical
D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone