Pegvisomant (Subcutaneous)

Pegvisomant is prescribed mainly for the patients whose conditions are not controlled by therapies like radiation or surgery, where using somatostatin analogs is unsuccessful or for patients for who cannot use any of those therapies.


Commonly referred to by its brand name Somavert, Pegvisomant is a synthetic protein that is akin to the human growth hormone (GH). The mode of action of pegvisomant is as a growth hormone receptor antagonist. This means it attaches itself to the same receptor in the body as growth hormone and obstructs the effects of the growth hormone. Structurally, Pegvisomant is a protein of recombinant DNA origin containing 191 amino acid deposits to which numerous polyethylene glycol (PEG) polymers are covalently bound.

The growth hormone (GH) is part of a group of hormones produced by a gland in the brain known as the Pituitary Gland. GH controls the growth and development of the body. When the pituitary produces an excessive amount of the growth hormone, the body reacts resulting in a condition called Acromegaly.

Acromegaly is a hormonal disorder characterized by excess growth in the organs, bones and soft tissues of the body. Individuals with acromegaly may have an exaggerated bone structure or even grow to abnormal heights. The condition mostly affects the face, arms, and legs. It is common among middle-aged adults.

The condition often goes unrecognized because it progresses slowly and the physical changes occur gradually, it may even take years to notice. You can have blood tests to determine whether you have too much GH, but these aren't always correct due to the fluctuation of the levels of the growth hormone during the day. As an alternative, your doctor may test for a protein known as insulin-like growth factor 1 (IGF-1). IGF_1 levels in your system can accurately indicate any sign of abnormal growth in the body. It is essential to get early diagnosis and treatment of the condition to prevent it from adversely affecting an individual. If left untreated, acromegaly could lead to severe complications and even death of the victim. Though the condition is not curable, it is possible to regulate it using the GH receptor antagonist, Pegvisomant. Pegvisomant medicine is in powder form and must be mixed with a liquid before using it and administration is by injection under the skin.

Conditions Treated

Type Of Medicine

  • Growth Hormone receptor antagonist

Side Effects

Though uncommon, some people may have awful and sometimes fatal side effects when using any medication. Some side effects occur in isolation, some simultaneously while some do not occur at all. Alongside its desired results, pegvisomant may cause some unwanted effects, some common and others rare. Get immediate medical assistance report to your doctor instantly if you experience one or a couple of the below common signs associated with severe side effects:

  • Itching, inflammation or infection at the injected spot
  • Inflammation; itching; rashes; red, swollen or blistered skin with or without the presence of a fever which are all symptoms of allergic reaction
  • Wheezing
  • Difficulty in breathing or talking
  • Unusual hoarseness
  • Swelling or bloating of the face, arms, feet, or mouth,
  • Lack of appetite, dark-coloured urine, tiredness, stomach pain or discomfort, throwing up or jaundice (yellowing of the eyes or skin) which could be indications of liver problems
  • Dizziness or light-headedness
  • Chest pain
  • Pounding headache
  • Any unexplained bruising or bleeding
  • Swollen arms or legs
  • Hardening or thickened skin
  • Blurred vision
  • Tingling of hands and feet
  • Unexplained weight gain or loss
  • Lower back and side pain

Some people will only experience minor side effects or none at all. Inform your doctor if any of these less common side effects persist.

  • Loose stools (diarrhea)
  • Back pain
  • Upset stomach
  • Signs of a flu
  • A runny nose
  • Stuffy nose
  • Symptoms of a common cold
  • Chills
  • Cough
  • Nervousness
  • Painful or difficult urination
  • Pounding in the ears
  • Abdominal pain or tenderness
  • Unusual tiredness or weakness
  • Nausea or vomiting
  • Joint pain
  • Shivering
  • Shortness of breath
  • Sweating
  • Trouble sleeping

However, above is not the comprehensive listing of all the side effects. Some of the side effects may not necessarily call for medical attention as they diminish and vanish as your body adjusts to the medication. In case you have any queries concerning side effects, do not hesitate to contact your doctor. Consult your medical provider for advice about the side effects. They may be able to enlighten you on how to avoid or ease some of these side effects. Check with your healthcare practitioner if any of the side effects persist. You may also report side effects to the FDA AT 1-800-FDA-1088.


Pegvisomant comes as a powdered drug mixed with diluents (liquid) prior to its usage. The first step in administering this medicine is preparation either by your doctor or yourself. You should know how to mix this medication correctly. Reconstitute the powder with 1ml of supplied diluent that is sterile water for injection. You should only prepare the dose if you're set to administer an injection and use it within 6 hours of reconstitution. The next step is injecting the medicine under your skin. However, you shouldn't do it at home if you are not entirely familiar with how to give the shot or dispose of needles and syringes. Your healthcare provider will guide you on the best body part to administer the pegvisomant shot, either in the thigh, upper arm, buttocks or tummy area. Ensure you rotate injection spots every time you administer an injection.

The medicine is packaged in a single-use bottle to be used only once. Avoid shaking the medication bottle.
The initial dose for Acromegaly in adults is 40 milligrams (mg) which is injected under your skin by your doctor. Then you will administer the maintenance dose of 10 to 30 mg as determined by your doctor, by subcutaneous injection daily. The dose of children under the age of 18 must be established by your doctor. Use pegvisomant regularly and as instructed by your doctor to get the ultimate benefit. Fill up on the prescription before it fully runs out.

If by any chance you skip a dose, take the moment it comes to your recollection. If not, just forget the missed dose and continue with your regular schedule. Avoid taking any additional medication to compensate for a skipped dose.

In the case of an overdose, get in touch with your doctor or Poison help to seek instant medical attention. One sign of an overdose could be fatigue or feeling unusually tired.

Drug interactions

Some medicines should not be used at the same time with others at all. In a situation where different medicines are used simultaneously, an interaction may occur. These interactions may cause changes in the effect of the drug or lead to the development of new adverse effects for that reason one should be cautious when using different drugs concurrently.

Pegvisomant has an extensive listing of other drugs that may influence its action. When you are taking this medicine, it is essential that you notify your healthcare provider if you are using any of the medicines indicated in the list below:

  • Acetaminophen
  • Acetohexamide
  • Actos
  • Adlyxin
  • Admelog
  • Afrezza
  • Airacof
  • Albiglutide
  • Alfentanil
  • Alogliptin
  • Alphen Expectorant
  • Amaryl (glimepiride)
  • Ambenyl
  • Ambifed CD
  • Anexia
  • Anaplex HD
  • Ammonium chloride/codeine
  • Anhydrous calcium iodide
  • Apidra
  • Asprin
  • Astramorph PF (morphine)
  • Balacet
  • Basaglar
  • Belbuca
  • Belladonna/ opium
  • Biotussin DAC
  • Bitex liquid
  • Buprenorphine
  • Buprenorphine buccal
  • Butorphanol
  • Codeine
  • Dextromoramide
  • Diamorphine
  • Difenoxin HCL
  • Diphenoxylate HCl
  • Dipipanone


  • Hydromorphone
  • Levorphanol
  • Liraglutide
  • Meperidine
  • Methadone
  • Morphine
  • Nalbuphine
  • Oxycodone
  • Oxymorphone
  • Pentazocine
  • Sufentanil
  • Tramadol
  • Tapentadol
  • Tridal
  • Troglitazone
  • Tussend
  • Tussinate
  • Tylenol with codeine
  • Ultiva
  • Ultracet
  • Iltram
  • Vanacet
  • Vanacon
  • Verdrocet
  • Vantrela ER
  • Vicodin
  • Vicoprofen
  • Vicotuss
  • Victoza
  • Wygesic
  • Xolox
  • Xodol
  • Zamicet
  • Zerlor
  • Zamadol
  • Zolvit
  • Zydol
  • Zyfrel
  • Zydone
  • Saxagliptin
  • Saxenda
  • Sitagliptin
  • Stadol
  • Roxicodone
  • Roxanol
  • Roxilox
  • Roxiprin
  • Repaglinide rezulin
  • Remifentanil


  • Pramlintide
  • Probuphine
  • Procof
  • Percocet
  • Pentazocine
  • Pegloticase
  • Panacet
  • Paregoric
  • Oxymorphone
  • Nesina
  • Notuss
  • Nalex
  • Miglitol
  • Methadose
  • Methadone
  • Micronase
  • Mintex
  • Mintuss
  • Medcodin
  • Meperidine
  • Meperitab
  • Meprizone
  • Metaglip
  • Metformin
  • Maxifed
  • Maxidone
  • Lorcet
  • Lortab
  • Lixisenatide
  • Liquicet
  • Lantus
  • Lazanda
  • Levorphanol
  • Krystexxa
  • Jardiance
  • Janumet
  • Januvia
  • Glucophage
  • Glucotrol
  • Glyburide
  • Glycron
  • Glyset
  • Glipizide
  • Fiasp
  • Fentora
  • Flowtuss
  • Exubera
  • Exenatide
  • Excof
  • Endodan
  • Embeda
  • Dymelor
  • Dolagesic
  • Doloral
  • Dolacet
  • Dihistine
  • DiaBeta

Take note that this is not an all-inclusive list of the drugs that interact with pegvisomant. Your doctor will give you all the information you need on all major and minor drug interactions before prescribing pegvisomant.

Warnings And Precautions

Certain precautions need to be taken to ensure that it is safe for you to use Pegvisomant drug. It is essential that your doctor monitor your progress at regular checkups to make sure that the drug is effective. First of all, you should stay off pegvisomant in case you're allergic to the drug or any part of it.

Inform your doctor know about all the drugs you are taking be it over the counter (OTC) or prescription, vitamins, and supplements as this medicines may interact with Pegvisomant leading to undesirable effects. Also, in case you have high blood sugar (diabetes), inform your doctor because Pegvisomant is known to lower blood sugar. This medication could also trigger high blood pressure; consequently, have your blood pressure checked with the instruction of your doctor.

Take note that the cover of the pegvisomant medicine bottles contains latex which may cause allergic reactions in individuals who are affected by latex. Inform your doctor if you have an allergy to latex before commencing using the medicine. You might also need regular blood tests to monitor your liver function. This drug is not likely to cause harm to an unborn child but notify your physician of any plans to get pregnant or are already pregnant during medication. Little is known of whether pegvisomant is harmful to a baby under lactation or pass into breast milk. A breastfeeding mother should take precautions.

Do not self-inject this medicine if you are not conversant with the process of injection or if you have no idea how to dispose of the used syringes and needles appropriately.


Manufacturers recommend that you store unopened vials of the powder medicine in the refrigerator at 2 to 8 degrees Celsius but do not freeze. Once the medicine that has been opened and reconstituted, store at room temperature (15 to 30 degrees Celsius) and use it strictly within 6 hours. Do not freeze the solution.
Keep the drug container out of reach of children or pets.

Do not keep mixed medicine that has exceeded its timeline or medicine no longer in use. Ask your healthcare professional on how you should dispose of any medicine you do not use. Ensure you throw away used needles in a tightly closed container which cannot be pricked by the needles.


Healthy growth and development in the body is triggered by the growth hormone produced by the pituitary gland in the brain. However, there are some instances whereby the growth hormone is produced in excess in the body resulting in a hormonal disorder called Acromegaly. Too much growth hormone (GH) accelerates organ enlargement and growth of bones.

Pegvisomant is a powder drug for solution used in the treatment of acromegaly. It is usually recommended where other therapies, surgery or radiation, have been tried but are unsuccessful or designated for patients whom these options are not appropriate. It has a structure that acts as a GH receptor antagonist. Treatment using Pegvisomant aims at having a normal IGF-1 level in the blood. The medicine is administered via injection under the skin. Administration of the drug is preferably by a qualified doctor or a well-trained individual. It does present some side effects which can be dealt with by your health provider. You should observe proper usage, dosage, and storage of the medication while taking the necessary precautionary measures to reap maximum benefits from this medicine.