Study of Thyrotropin-Releasing Hormone in Normal Volunteers and in Patients With Thyroid or Pituitary Abnormalities
Healthy - Pituitary Disease - Thyroid Disease
Conditions: official terms
Pituitary Diseases - Thyroid Diseases
Conditions: Keywords
Hypothalamic Releasing Factor, Neuropeptide, Diagnostic Testing, Pituitary Tumors, Central Hypothyroidism, Pituitary Disorder, Thyroid Disorder, Healthy Volunteer, HV
Study Type
Study Phase
Phase 2
Study Design
Primary Purpose: Treatment
Name: TRH (Thyrotropin Releasing Hormone)
Type: Drug
Overall Status
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.
Detailed Description
Thyrotropin releasing hormone (TRH) is a neuropeptide used in the diagnostic evaluation of patients with dysfunction of the hypothalamic-pituitary-thyroid (HPT) axis. In healthy individuals, administration of TRH intravenously results in pituitary secretion of thyrotropin [thyroid-stimulating hormone (TSH)], which in turn stimulates the thyroid gland release of thyroid hormones; thyroxine (T4) and triiodothyronine (T3). TRH stimulates the secretion of other pituitary hormones under normal physiologic as well as pathologic conditions. The purpose of this study is to test the safety and activity of a new preparation of TRH produced by the Pharmaceutical Development Section of the Clinical Center Pharmacy at the NIH. This preparation is similar to a previously commercially available preparation. Normal, healthy adults will be recruited to undergo a standard TRH test using the new preparation. TSH, prolactin and thyroid hormones are measured after the administration of TRH. After the safety, activity and diagnostic comparability are established, the preparation will be used for routine diagnostic testing and research in adults and children.
Criteria for eligibility
Healthy Volunteers: No
Maximum Age: 65 Years
Minimum Age: 2 Years
Gender: Both

Diagnostic Study Protocol

All adults and children requiring dynamic testing of the hypothalamic-pituitary axis for the evaluation of pituitary reserve, inconsistent thyroid function test, inappropriate TSH secretion, or pre-and post-operative evaluation of pituitary adenomas (glycoprotein hormone secreting tumors, growth hormone secreting tumors and TSH secreting tumors).


- Uncontrolled hypertension;

- Uncontrolled seizure disorder;

- Unstable coronary disease;

- Known allergy to TRH.

Research protocols

TRH is available for use in other IRB approved research protocols either using the standard diagnostic testing protocol or the modified TRH test.


- Untreated hypertension;

- Coronary artery disease;

- History of asthma;

- History of seizures;

- Pregnancy;

- Known allergy to TRH.
National Institutes of Health Clinical Center, 9000 Rockville Pike
Bethesda, Maryland, United States
Status: Recruiting
Contact: For more information at the NIH Clinical Center contact Patient Recruitment and Public Liaison Office (PRPL) - 800-411-1222 -
Start Date
February 2003
Completion Date
January 2099
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
National Institutes of Health Clinical Center (CC)
Record processing date processed this data on July 28, 2015 page