[Side-effects of the clonidine test in 20 children with short stature].

A single oral dose of 0.15 mg/m2 of clonidine was given to twenty children and adolescents (range 1.6 to 17.4 years) with short stature (height standard deviation score -3.3 +/- 1.1). In 18 (90%) tests the plasma growth hormone response was positive (13.5 +/- 7 ng/ml) without false-negatives. 16 (80%) were drowsy, lasting for 3-4 hours. The systolic blood pressure decreased from 99.6 +/- 13 mmHg (basal) to 81 +/- 13.9 and 85.8 +/- 11.8 (p less than 0.05), after 180 and 240 minutes of clonidine administration. The cardiac frequency decreased from 92 +/- 18 to 74 +/- 14 beat/minute (p less than 0.05). A positive linear correlation (p less than 0.05) was found between peak serum growth hormone concentration and peak systolic hypotension (r = 0.707). The great sensitivity of the clonidine test is confirmed. The side-effects observed suggest that it is necessary to control blood pressure during the 5 hours following the oral administration of clonidine.