Study of Thyrotropin-Releasing Hormone in Normal Volunteers and in Patients With Thyroid or Pituitary Abnormalities
Status:
Completed
Trial end date:
2014-09-26
Target enrollment:
Participant gender:
Summary
This study will determine the safety and activity of a new formulation of
thyrotropin-releasing hormone (TRH), a drug used for diagnosing and evaluating patients with
certain thyroid gland abnormalities. Normal thyroid gland function depends on proper chemical
signaling between the thyroid gland, the hypothalamus (the part of the brain where TRH is
made), and the pituitary (another part of the brain). The TRH test helps assess this
interaction. Production of the only FDA-approved preparation of TRH was stopped in July 2002.
As a result, to have a continuous source of TRH available for NIH clinical and research
purposes, the NIH Clinical Center (CC) Pharmacy Department produced a pharmaceutical grade
formulation of TRH for patient use. This study will test the CC formulation in healthy
volunteers to show that its activity and side effects are similar to those of the previously
available commercial test preparation. It will then be studied in CC patients for whom the
diagnostic test is recommended.
Healthy volunteers between 18 and 65 years of age and all patients requiring TRH evaluation
of hypothalamic-pituitary-thyroid gland interaction may be eligible for this study. Patients
include those with pituitary reserve, inconsistent thyroid function test, inappropriate TSH
secretion, or pre- and post-operative evaluation of pituitary tumors. Normal volunteers will
be screened with a medical history, physical examination, and blood tests. Women of
child-bearing potential will be given a pregnancy test; pregnant and breast-feeding women may
not participate.
The TRH test procedure will be the same for healthy volunteers and patients. All participants
fast from midnight before the morning of the test. In the morning, a catheter (flexible
plastic tube) is inserted into an arm vein for easy injection of the TRH and collection of
blood samples. Blood pressure is monitored before and during the test. A blood sample is
drawn, and then TRH is given through the catheter over a 1-minute period. Another nine blood
samples are collected over a 3-hour period from the time of the TRH injection for measuring
levels of various hormones. A total of less than 4 tablespoons of blood is taken for the
test.
Phase:
Phase 2
Details
Lead Sponsor:
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)