Thyrel TRH (Intravenous)

Protirelin is used to check how well the anterior pituitary gland is working in people who may have certain thyroid conditions. This test can help find the problem or confirm if the medicine dose being used is correct.

Protirelin triggers the release of a hormone called thyroid-stimulating hormone (TSH) from the anterior pituitary gland. TSH then prompts the thyroid gland to work. By measuring the amount of TSH in the blood after giving protirelin, the doctor can assess how well the anterior pituitary is functioning.

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

Protirelin should only be used under a doctor’s supervision.

In deciding to use a diagnostic test, you and your doctor must consider the risks of the test against the benefits it could provide. Additionally, other factors may influence the results of the test. For this test, consider the following:

Allergies

Inform your doctor if you have ever had any unusual or allergic reactions to this medicine or any other medicines. Also, let your healthcare professional know if you have any other 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, 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 adults compared to younger adults.

Breast Feeding

There are no adequate studies in women to determine the risk to infants when using this medication during breastfeeding. Consider the potential benefits and risks before taking this medication while breastfeeding.

Interactions with Medicines

Some medicines should never be used together, while others can be used together even if an interaction might occur. In these situations, your doctor may adjust the dose or take other precautions. When you are receiving this diagnostic test, it's especially important for your healthcare professional to know if you are taking any of the medicines listed below. The following interactions have been highlighted due to their potential significance and are not necessarily all-inclusive.

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

• Cyproheptadine
• Thioridazine

Interactions with Food/Tobacco/Alcohol

Some medicines should not be taken around the time of eating food or specific types of food due to possible interactions. Using alcohol or tobacco with certain medicines may also lead to interactions. Discuss with your healthcare professional about using your medicine with food, alcohol, or tobacco.

Other Medical Problems

Other medical conditions may impact 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 or
• High blood pressure or
• Stroke (history of)—Sudden changes in blood pressure caused by protirelin may increase risk for patients with these conditions

• Kidney disease—Test results may be affected if the patient has 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.