In the U.S.—

In Canada—

• Diagnostic aid, hypothalamic-pituitary-thyroid axis function

Protirelin (proe-TYE-re-lin ) 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. It is available in the following dosage form:

Parenteral
• Injection (U.S. and Canada)

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, test results may be affected by other things. For protirelin, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to protirelin. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Studies have not been done in humans. However, studies in rabbits have shown that protirelin increases the chance of death of the fetus when given in doses 1½ and 6 times the human dose.

Breast-feeding—Protirelin has not been reported to cause problems in nursing babies. However, it may cause extra swelling of the breasts and leaking of milk for up to 2 or 3 days after it is given.

Children—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.

Older adults—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.

Other medicines—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. Tell your health care professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

• 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

Your doctor may ask you not to eat for several hours before the test or to eat a low-fat meal before the test. This will not be necessary for all patients. If it is necessary for you, follow your doctor's instructions carefully . Otherwise, this test may not work and may have to be done again.

Along with its needed effects, a medicine may cause some unwanted effects. Check with your health care professional as soon as possible if either of the following side effects occurs:

• Rare
  • Fainting 
  
  

• For patients with pituitary tumors--Rare
  • Loss of vision (temporary) 
  
  

Protirelin commonly causes some side effects just after it is given. Usually they last for only a few minutes. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Flushing or redness of skin;  frequent urge to urinate;  headache (sometimes severe);  lightheadedness;  nausea;  stomach pain;  unpleasant taste in mouth or dryness of mouth 
  
  

• Less common
  • Anxiety;  drowsiness;  pressure in the chest or tightness in throat;  sweating ;  tingling 
  
  

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