Protirelin (Intravenous)

Protirelin is used to test how well the anterior pituitary gland responds in people who may have certain thyroid gland conditions. This test can help identify the issue or confirm the correct dose of medication being used.

Protirelin causes the release of a hormone called thyroid-stimulating hormone (TSH) from the anterior pituitary gland. TSH then stimulates the thyroid gland. By measuring the level of TSH in the blood after receiving protirelin, the doctor can assess how well the anterior pituitary is functioning.

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

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

In deciding to use a diagnostic test, you and your doctor need to think about any risks of the test compared to the benefits it may provide. Other factors can also influence test results. For this test, consider the following:

Allergies

Inform your doctor if you have ever had any unusual reactions or allergies to this medicine or any other medicines. Also, let your healthcare professional know about any other allergies you may have, such as to foods, dyes, preservatives, or animals. For non-prescription products, carefully read the label or package ingredients.

Pediatric

This medicine has been tested in children and, at effective doses, has not shown different side effects or problems in children compared to adults.

Geriatric

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

Breast Feeding

There are not enough studies in women to determine the risk to infants when using this medication while breastfeeding. Consider the potential benefits against the potential risks before taking this medication during breastfeeding.

Interactions with Medicines

Some medicines should not be used together at all, while in other cases, two different medicines may be used together even if an interaction might occur. In these situations, your doctor may adjust the dose, or other precautions may be necessary. It is especially important for your healthcare professional to know if you are taking any of the medicines listed below while receiving this diagnostic test. The following interactions have been chosen based on their potential significance and may not include all possible interactions.

Receiving this diagnostic test with any of the following medicines may increase the risk of certain side effects, but using both drugs may be the best option for you. If both medicines are prescribed together, your doctor may adjust the dose or frequency of one or both medicines.

• Cyproheptadine
• Thioridazine

Interactions with Food/Tobacco/Alcohol

Some medicines should not be taken at or around mealtime or with certain types of food due to possible interactions. The use of alcohol or tobacco with certain medicines can also lead to interactions. Discuss with your healthcare professional how your medicine interacts with food, alcohol, or tobacco.

Other Medical Problems

Other medical issues may affect the use of this diagnostic test. Be sure to inform your doctor if you have any other medical problems, especially:

• Heart or blood vessel disease
• High blood pressure
• Stroke (history of)—Sudden changes in blood pressure caused by protirelin may put patients with these conditions at higher risk

• Kidney disease—Test results may be affected if you have kidney disease.

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

• Fainting

For patients with pituitary tumors

Rare

• 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

• 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 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.

In the U.S.

• Thyrel TRH

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.