Pharmacokinetics of oral terguride in patients with a prolactinoma.

The pharmacokinetics of oral terguride 1 mg was evaluated in a single-dose study in 8 patients with a prolactinoma and one with acromegaly. A radioreceptor assay was used to measure the plasma levels of terguride. The peak plasma concentration (2.3 +/- 0.7 ng/ml, mean +/- SEM) was attained within 1 h of drug administration. Moment analysis gave a mean residence time of 4.3 +/- 0.6 h. Plasma prolactin was also determined by radioimmunoassay. The plasma prolactin was reduced to 30 +/- 3% of its pretreatment value after 4 h.