Enter drug's generic or brand name below. Results will appear here. Note: all drug related information obtained on this page is provided by RX List.
Using the RX LIST database:
(1) Enter the drug name in the search box below and hit ENTER
(2) The rx list web site will open here with the drug search completed. Next, scroll down the page to locate the link to the drug you are searching for and then click on the link.
THYREL® TRH
(protirelin)
Injection
FOR INTRAVENOUS ADMINISTRATION
Chemically, Thyrel® TRH (protirelin) is identified as 5-oxo-L-prolyl-L-histidyl-L-proline amide. It is a synthetic tripeptide that is believed to be structurally identical to the naturally-occurring thyrotropin-releasing hormone produced by the hypothalamus. The CAS Registry Number is 24305-27-9. The structual formula is:
Thyrel TRH (protirelin) is supplied as 1 mL ampuls. Each ampul contains 500 µg protirelin in a sterile nonpyrogenic isotonic saline solution having a pH of approximately 6.5. In addition, each ampul contains sodium chloride 9.0 mg, Water for Injection, hydrochloric acid and sodium hydroxide as needed to adjust pH. Thyrel TRH (protirelin) is intended for intravenous administration.
Thyrel TRH (protirelin) is indicated as an adjunctive agent in the diagnostic assessment of thyroid function. As an adjunct to other diagnostic procedures, testing with Thyrel® TRH (protirelin) may yield useful information in patients with pituitary or hypothalamic dysfunction.
Thyrel TRH (protirelin) is indicated as an adjunct to evaluate the effectiveness of thyrotropin suppression with a particular dose of T4 in patients with nodular or diffuse goiter. A normal TSH baseline value and a minimal difference between the 30 minute and baseline response to Thyrel TRH (protirelin) injection would indicate adequate suppression of the pituitary secretion of TSH.
Thyrel TRH (protirelin) may be used, adjunctively, for adjustment of thyroid hormone dosage given to patients with primary hypothyroidism. A normal or slightly blunted TSH response, thirty minutes following Thyrel TRH (protirelin) injection, would indicate adequate replacement therapy.
Thyrel TRH (protirelin) is intended for intravenous administration with the patient in the supine position. The drug is administered as a bolus over a period of 15 to 30 seconds, with the patient remaining supine until all scheduled postinjection blood samples have been taken. Blood pressure should be measured before Thyrel TRH (protirelin) is administered and at frequent intervals during the first 15 minutes thereafter (see WARNINGS). Have the patient urinate before injecting Thyrel TRH (protirelin) .
Adults: 500 µg. Doses between 200 and 500 µg have been used. 500 µg is considered the optimum dose to give the maximum response in the greatest number of patients. Doses greater than 500 µg are unlikely to elicit a greater TSH response.
Children age 6 to 16 years; 7 µg/kg body weight up to dose of 500 µg.
Infants and children up to 6 years: Experience is limited in this age group; doses of 7 µg/kg have been administered.
One blood sample for TSH assay should be drawn immediately prior to the injection of Thyrel® TRH, and a second sample should be obtained 30 minutes after injection.
The TSH response to Thyrel TRH (protirelin) is reduced by repetitive administration of the drug. Accordingly, if the Thyrel TRH (protirelin) test is repeated, an interval of seven days before testing is recommended.
Elevated serum lipids may interfere with the TSH assay. Thus, fasting (except in patients with hypopituitarism) or a low-fat meal is recommended prior to the test.
Interpretation of the TSH response to Thyrel TRH (protirelin) requires an understanding of thyroid-pituitary-hypothalamic physiology and knowledge of the clinical status of the individual patient.
Because the TSH test results may vary with the laboratory, the physician should be familiar with the TSH assay method used and the normal range for the laboratory performing the assay. TSH response 30 minutes after Thyrel TRH (protirelin) administration in normal subjects and in patients with hyperthyroidism and hypothyroidism are presented in Figure 1. The diagnoses were established prior to the administration of Thyrel TRH (protirelin) on the basis of the clinical history, physical examination, and the results of other thyroid and/or pituitary function tests.
Among the normal euthyroid subjects, women and children were found to have higher levels of TSH at 30 minutes than men.
Among the patients with hyperthyroidism or primary (thyroidal), secondary pituitary), or tertiary (hypothalamic) hypothyroidism, no significant differences in TSH levels by age or sex were found.
Normal: Baseline TSH levels of less than 10 microunits/mL (µU/mL) were observed in 97% of euthyroid normal subjects tested. Thirty minutes after Thyrel TRH (protirelin) , the serum TSH increased by 2.0 mµ/mL or more in 95% of euthyroid subjects.
Hyperthyroidism: All hyperthyroid patients tested had baseline TSH levels of less than 10 µU/mL and a rise of less than 2 µU/mL 30 minutes after Thyrel® TRH.
Primary (thyroidal) hypothyroidism: The diagnosis of primary hypothyroidism is frequently supported by finding clearly elevated baseline TSH levels; 93% of patients tested had levels above 10 µU/mL, Thyrel TRH (protirelin) administration to these patients generally would not be expected to yield additional useful information. Ninety-four percent of patients with primary hypothyroidism given Thyrel® TRH in clinical trials responded with a rise in TSH of 2.0 µU/mL or greater. Since this response is also found in normal subjects, Thyrel TRH (protirelin) testing does not differentiate primary hypothyroidism from normal.
| Baseline Serum TSH (µU/mL) | Change of Serum TSH (µU/mL) at 30 minutes | |
| Euthyroidism (normal thyroid function) | 10 or less (usually 6 or less; 20% have Is It Normal to Have a Curved Penis?
Health Solutions From Our Sponsors
|
