How does this medication work? What will it do for me?

Somatropin belongs to a class of medications known as growth stimulants. Somatropin is a synthetic version of growth hormone. Growth hormone is made naturally in our bodies by the pituitary gland and is necessary for the stimulation of growth in children.

This medication is used to treat:

  • growth hormone deficiency in children (to replace growth hormone that they are unable to produce enough naturally)
  • growth failure in children due to chronic kidney disease
  • growth failure in children born small for gestational age (SGA) who do not catch up in growth by 2 years or later
  • short stature in people with Turner's syndrome
  • adults who have growth hormone deficiency (this can result from pituitary disease, surgery, radiation therapy, diseases of the hypothalamus, or trauma)

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

Powder

3.33 mg
Each vial contains 3.33 mg somatropin. The diluent is 5 mL Bacteriostatic Sodium Chloride Injection. Non-medicinal ingredients: disodium phosphate dihydrate, mannitol, sodium chloride, and sodium dihydrogen phosphate monohydrate.

5 mg
Each vial contains 5 mg somatropin. The diluent is 10 mL Bacteriostatic Water for Injection. Nonmedicinal ingredients: phosphoric acid and sucrose.

8.8 mg
Each vial contains 8.8 mg somatropin. The diluent is 10 mL Bacteriostatic Water for Injection. Nonmedicinal ingredients: phosphoric acid, sodium hydroxide, and sucrose.

Liquid

6 mg
Each cartridge contains 6 mg somatropin (5.83 mg/mL). Nonmedicinal ingredients: sucrose, Poloxamer 188, phenol, and citric acid.

12 mg
Each cartridge contains 12 mg somatropin (8 mg/mL). Nonmedicinal ingredients: sucrose, Poloxamer 188, phenol, and citric acid.

20 mg
Each cartridge contains 20 mg somatropin (8 mg/mL). Nonmedicinal ingredients: sucrose, Poloxamer 188, phenol, and citric acid.

How should I use this medication?

The recommended dose depends on the circumstances and body weight of the person being treated. Your doctor will determine the appropriate dose of somatropin to be injected.

Somatropin is administered by injection only. It is usually injected subcutaneously (under the skin), although it can be given intramuscularly (into the muscle) if your doctor prefers. If it is injected under the skin, it is important to rotate the site of injection in order to minimize the risk of fat wasting at the site of injection.

If you are using this medication at home, your doctor will ensure that you understand exactly how to use it. Make sure you ask any and all questions necessary to ensure that you use it exactly as prescribed. Please refer to the appropriate package insert for details on how to mix the medicine and for proper injection procedures. It is important to visit your doctor regularly during therapy to ensure that the medication is working safely and effectively.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to use this medication exactly as prescribed by your doctor. If you miss a dose of the medicine, call your doctor for further instructions. Do not take a double dose to make up for a missed one.

Follow the package instructions for storing the medication. Do not use the solutions if they are discoloured or contain particles.

Keep this medication out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Somatropin injection should not be used by or given to anyone who:

  • is allergic to somatropin or any ingredients of the medication
  • is a child with closed epiphyses (growth plates)
  • has active cancer
  • has a brain tumour
  • has an acute illness due to complications of surgery, has respiratory (breathing) failure, or has just had a serious accident
  • has certain types of eye damage due to diabetes (proliferative or preproliferative diabetic retinopathy)
  • has Prader-Willi syndrome and is severely obese or has severe breathing problems

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • carpal tunnel syndrome
  • growth of birthmarks
  • joint pain
  • muscle pain
  • redness, pain, or swelling at site of injection
  • stiffness in the arms or legs
  • swelling of hands, feet, or lower legs
  • unusual tiredness or weakness

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

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

  • depression of skin at place of injection
  • ear infection or other ear problems (in Turner's syndrome)
  • headache
  • limp
  • nausea and vomiting
  • pain in hip or knee
  • skin rash or itching
  • severe abdominal pain, particulary in children
  • skin rash or itching
  • symptoms of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • severe or frequent headaches with nausea and vomiting or vision problems
  • signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should take this medication.

Cancer: There may be an increased risk of tumour growth, both cancerous and non-cancerous when growth hormone is used by survivors of childhood cancer. Discuss any concerns you may have with your doctor.

Diabetes: Somatropin may cause an increase in blood sugar levels and glucose tolerance may change. People with diabetes may find it necessary to monitor their blood sugar more frequently while using this medication.

If you have diabetes or are at risk for developing diabetes, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Hypothyroidism (low level of thyroid hormone): If you have uncontrolled hypothyroidism, treatment with somatropin may not work as well as it could. Discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Treatment with somatropin may trigger hypothyroidism. If you experience unexplained weight gain, muscle aches or stiffness, constipation, dry skin or fatigue, this may be a result of too little thyroid hormone and you should contact your doctor as soon as possible.

Scoliosis: People with scoliosis are at risk of a worsening of their condition while taking somatropin. If you have scoliosis, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if somatropin passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

What other drugs could interact with this medication?

There may be an interaction between somatropin and any of the following:

  • corticosteroids (e.g., cortisone, prednisone)
  • cyclosporine
  • diabetes medications (e.g., glimepiride, insulin, metformin)
  • estrogen

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.