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The Testing Process

The Procedures to Expect. The IGF-1 Screening to Ask For.

If your pediatrician or family doctor finds that your child has significant short stature, he or she will refer you to a Pediatric Endocrinologist. Because diagnosing short stature can be a complex process, it may take several trips to the Pediatric Endocrinologist before a specific short stature disorder is diagnosed.

To reach a diagnosis, your child's doctor is likely going to do the following things:

  • Measure your child
  • Ask questions about family history
  • Rule out the prospect of other diseases and conditions that can affect height
  • Having done the above, your doctor may then conduct several blood tests to determine levels of growth hormone and IGF-1 in your child's body

IMPORTANT: Your doctor should be testing your child for both growth hormone and IGF-1 in order to reach an informed diagnosis. IGF-1 screening measures blood levels of IGF-1, which is an important hormone for growth. Don't be afraid to ask your child's doctor about IGF-1 screening during the diagnostic workup.

The GH Stimulation Test

Based on the result of your child's IGF-1 screening, your child may then be given a growth hormone stimulation test. The two results together will provide their physician with a more complete picture from which to make an accurate diagnosis.

During a GH stimulation test:

  • A sample of blood is drawn after your child has fasted for 10-12 hours.
  • Then, under close medical supervision, your child is given an intravenous solution (L-dopa or arginine), which stimulates the pituitary gland to produce growth hormone, and have been known to make children feel sleepy or nauseous. You can help calm your child by assuring her that these are perfectly normal reactions and that they will not last long.
  • Next, blood samples are drawn at timed intervals and GH levels are tested. The entire process may take several hours. It's a good idea to prepare your child for a lengthy office visit and bring along reading material to make the time pass more quickly.
  • Responses to GH testing vary and interpreting results can be complex; thus, GH testing is not consistently reliable in determining if patients need GH therapy.18,21

If IGF-1 Is Exceptionally Low but GH Is Normal

If your child's growth hormone levels turn out to be normal or high but his IGF-1 levels are exceptionally low, your doctor may diagnose your child as having severe Primary IGFD. If your doctor already has performed a GH stimulation test on your child, talk to your doctor about IGF-1 screening.

If a GH Stimulation Test Has Been Conducted but IGF-1 Levels Have Not Been Checked

Your child's growth hormone levels tell only part of his or her growth story. Your child's IGF-1 levels should also be checked. IGF-1 levels are checked with a simple blood test. Be sure to talk to your child's doctor about obtaining an IGF-1 screening.

A Checklist for Parents—What You Can Do to Help

  • Assure your child. To a child, having blood drawn can be scary. Remember to assure your child that the testing process doesn't last long and more importantly, that it's necessary so that your child's doctors can figure out why he or she isn't growing properly.
  • Insist on IGF-1 screening. Talk to your child's doctor about screening for IGF-1 deficiency. This is important for any child being tested and is especially important for those who have been taking growth hormone therapy and have not responded during 6 to 12 months of treatment. Remember: don't be afraid to talk to your child's doctor about IGF-1 screening. You both want what's best for your child and what's best begins with an accurate diagnosis.
  • Know that testing is not a perfect science. Some tests may be inaccurate or the results may be unclear, and may not permit your child's doctor to make a precise diagnosis. Your child may need to be retested. Your child's doctor also may not yet fully understand the role of IGF-1 deficiency in contributing to growth disorders. It is important to be patient and persistent.
  • Be an advocate for your child. Talk to your doctor about having your child screened for severe Primary IGFD.

Indication and Important Safety Information

Who is Increlex® for?
INCRELEX is used to treat children who are very short for their age because their bodies do not make enough IGF-1. This condition is called severe primary IGF-1 deficiency. INCRELEX should not be used instead of growth hormone.

Who should not use Increlex?
Your child should not take INCRELEX if your child: has finished growing (the growth plates at the end of the bones are closed); has cancer; has other causes of growth failure; OR is allergic to mecasermin or any of the inactive ingredients in INCRELEX. INCRELEX has not been studied in children under 2 years of age and should never be used in newborns. Your child should never receive INCRELEX through a vein.

Before your child takes Increlex, you should tell your child's doctor about:
All of your child's health conditions, including: diabetes, kidney problems, liver problems, allergies, scoliosis (curved spine), pregnancy, or breast-feeding.

All the medicines (prescription and nonprescription), vitamins, and herbal supplements your child takes, especially insulin or other anti-diabetes medicines, which may require dose adjustment of these medicines.

What are possible side effects of increlex (some of which can be serious)?
Low blood sugar (hypoglycemia). Only give your child INCRELEX right before or right after (20 minutes on either side of) a snack or meal to reduce the chances of hypoglycemia. Signs include dizziness, tiredness, restlessness, hunger, irritability, trouble concentrating, sweating, nausea, and fast or irregular heartbeat. Do not give your child INCRELEX if your child is sick or cannot eat.

Severe hypoglycemia may cause unconsciousness, seizures, or death. People taking INCRELEX should avoid participating in high risk activities (such as driving) within 2 to 3 hours after an INCRELEX injection.

Increased pressure in the brain (intracranial hypertension). INCRELEX, like growth hormone, can sometimes cause a temporary increase in pressure within the brain. Symptoms include persistent headache, blurred vision, and nausea with vomiting.

Allergic reactions. Your child may have a mild or serious allergic reaction with Increlex. Call your child's doctor right away if your child gets a rash or hives. Hives, also known as urticaria, appear as a raised, itchy skin reaction. Hives appear pale in the middle with a red rim around them. Hives generally appear minutes to hours after the injection and may sometimes occur at numerous places on the skin. Get medical help immediately if your child has trouble breathing or goes into shock, with symptoms like dizziness, pale, clammy skin, and/or passing out.

Enlarged tonsils. Signs include: snoring, difficulty breathing or swallowing, sleep apnea (a condition where breathing stops briefly during sleep), or fluid in the middle ear.

A bone problem called slipped capital femoral epiphysis. This happens when the top of the upper leg (femur) slips apart from the rest of the bone. Seek immediate medical attention if your child develops a limp or has hip or knee pain.

Worsened scoliosis (caused by rapid growth).

Injection site reactions including: swelling, loss of fat, increase of fat, pain, redness, or bruising. This can be avoided by changing/rotating the injection site at each injection.

Your child's doctor is your primary source of information about treatment. For more information, please talk to your doctor and download and review the full Patient Prescribing Information.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit, or call 1-800-FDA-1088.

For Patient Product Information, click here.