Effect of clonidine on plasma cortisol concentrations

Area of Science:

• Pediatric Endocrinology
• Pharmacology
• Endocrinology

Background:

• The effect of clonidine on plasma cortisol levels in children is debated.
• It is unclear if observed cortisol drops are due to clonidine or natural diurnal variation.

Purpose of the Study:

• To compare plasma cortisol patterns in children following clonidine administration with normal diurnal cortisol variation.
• To determine if clonidine causes a significant decrease in cortisol levels beyond normal diurnal changes.

Main Methods:

• Children received an early morning oral dose of clonidine (0.075 or 0.150 mg/m2).
• Plasma cortisol concentrations were measured and compared to cortisol levels during normal diurnal variation.
• A crossover design was used where some subjects had the diurnal study first, followed by the clonidine study, and vice versa.

Main Results:

• Clonidine, at both tested doses (0.075 and 0.150 mg/m2), did not induce a fall in plasma cortisol concentrations.
• The observed changes in cortisol levels after clonidine administration were not greater than those seen with normal diurnal variation.

Conclusions:

• Early morning oral clonidine administration does not significantly suppress plasma cortisol levels in children.
• The study concludes that clonidine's effect on cortisol is not distinct from normal diurnal cortisol fluctuations.