Changes in plasma prolactin and catecholamine metabolite levels following acute needle stick in children.

Changes in plasma levels of prolactin (PRL), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) following insertion of an indwelling catheter into a forearm vein were assessed in 11 boys with attention-deficit hyperactivity disorder. Results indicated decreases in plasma PRL and HVA, but not MHPG, from the time of needle stick until 105 min post-insertion. These data indicate a significant increase in plasma PRL and HVA in children following needle stick which gradually decreases over a 1.5-2-h period. These stress-induced changes indicate that values obtained immediately after needle insertion cannot be assumed to accurately reflect baseline levels.