Description and Brand Names

Drug information provided by: Merative, Micromedex®

US Brand Name

  1. Thyrel TRH

Descriptions


Protirelin is used to test the response of the anterior pituitary gland in people who may have certain medical conditions involving the thyroid gland. Testing with this medicine may help to identify the problem or may ensure that the dose of medicine being used is correct.

Protirelin stimulates release of a hormone called thyroid-stimulating hormone or TSH from the anterior pituitary gland. TSH then stimulates the thyroid gland. By measuring the amount of TSH in the blood after protirelin is given, the doctor can determine how well the anterior pituitary is working.

How test is done: First, a sample of your blood is taken. Then protirelin is given by injection by your doctor. The dose of protirelin may be different for different patients. Adults are usually given 500 micrograms (mcg) injected into a vein. The dose for children is based on body weight and must be determined by your doctor. A little while after the dose is given, one or more blood samples are taken. Then the results of the test are studied. You will be asked to lie down before, during, and for 15 minutes after the test. This is to prevent dizziness and possible fainting.

Protirelin is to be used only under the supervision of a doctor.

Before Using

In deciding to use a diagnostic test, any risks of the test must be weighed against the good it will do. This is a decision you and your doctor will make. Also, other things may affect test results. For this test, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

This medicine has been tested in children and, in effective doses, has not been shown to cause different side effects or problems in children than it does in adults.

Geriatric

This medicine has been tested and has not been shown to cause different side effects or problems in older people than it does in younger adults.

Breastfeeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving this diagnostic test, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Receiving this diagnostic test with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Cyproheptadine
  • Thioridazine

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this diagnostic test. Make sure you tell your doctor if you have any other medical problems, especially:

  • Heart or blood vessel disease or
  • High blood pressure or
  • Stroke (history of)—Sudden changes in blood pressure caused by protirelin may put patients with these conditions at greater risk
  • Kidney disease—Test results may be affected if patient has kidney disease

Proper Use

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

Rare

  1. Fainting

For patients with pituitary tumors

  1. Loss of vision (temporary)

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  1. Flushing or redness of skin
  2. frequent urge to urinate
  3. headache (sometimes severe)
  4. lightheadedness
  5. nausea
  6. stomach pain
  7. unpleasant taste in mouth or dryness of mouth

Less common

  1. Anxiety
  2. drowsiness
  3. pressure in the chest or tightness in throat
  4. sweating
  5. tingling

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.