Denosumab belongs to a family of medications known as monoclonal antibodies. Specifically, it inhibits a protein that your body uses to signal for removing old bone tissue. Denosumab works by reducing the amount of bone your body breaks down, making your bones less likely to break.

Denosumab is used to treat osteoporosis for postmenopausal people who have a high risk of fracture or who have not tolerated or responded to other osteoporosis medications. It is also used to increase bone mass in people who have osteoporosis and are at high risk of having a fracture, have a history of osteoporotic fracture, or have not tolerated or responded to other osteoporosis medications.

This medication is also used to increase bone mass for people who are being treated with an aromatase inhibitor for breast cancer that has not spread to other parts of the body. It is also used to increase bone mass and reduce fractures for people who have prostate cancer that has not spread to other parts of the body and who are receiving medication to reduce testosterone levels.

Denosumab may also be used to increase bone mass for people who are taking or have just started to take glucocorticoids (e.g., prednisone, dexamethasone) for a long period of time.

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 being given this medication, speak to your doctor. Do not stop using 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 use this medication if their doctor has not prescribed it.

The recommended dose of denosumab is 60 mg injected once every 6 months. It is injected subcutaneously (under the skin) of the upper arm, upper thigh, or abdomen. Your doctor may show you how to give yourself the injections, or a health care professional will inject the medication for you.

Many things can affect the dose of a 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 using the medication without consulting your doctor.

It is important that this medication be used exactly as recommended by your doctor. If you miss an appointment to receive denosumab, contact your doctor as soon as possible to reschedule your appointment. If you are injecting this medication yourself and miss a dose, use it as soon as you remember. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

This medication is stored in the refrigerator. Protect it from light and do not allow this medication to freeze. Keep it out of the reach of children. When removed from the refrigerator, it can also be stored at room temperature for 30 days. It should be allowed to reach room temperature before injecting.

Each 1 mL single-use prefilled syringe of sterile, preservative-free, clear, colourless-to-slightly-yellow solution contains 60 mg of denosumab. Nonmedicinal ingredients: sorbitol, acetate, polysorbate 20, water for injection (USP), and sodium hydroxide to adjust for pH.

Prefilled syringes do not contain natural rubber latex.

Do not use denosumab if you:

• are allergic to denosumab or any ingredients of the medication
• have low blood calcium levels
• are pregnant or trying to become pregnant

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.

• common cold (runny nose or sore throat)
• hair loss
• itchy, dry skin
• pain in muscles, arms, legs, or back
• skin rash
• pain, redness, or swelling at the site of the injection

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

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

• signs of pancreatitis (e.g., abdominal pain on the upper left side, back pain, nausea, fever, chills, rapid heartbeat, swollen abdomen)
• sores in the mouth or gums
• symptoms of an ear infection (e.g., ear pain, feeling of fullness in the ear, hearing loss, nasal congestion)
• symptoms of fracture in the long bone of the leg (e.g., new or unusual pain in the hip or thigh)
• symptoms of a skin infection (e.g., redness, swelling, warmth, tenderness)
• symptoms of low blood calcium levels (e.g., muscle spasms, twitches, or cramps; numbness or tingling in the fingers, toes, or around the mouth)
• symptoms of a urinary tract infection (e.g., pain when urinating, urinating more often than usual, low back or flank pain)
• unusual pain and swelling of the jaw

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

• chest pain
• fast or irregular heartbeat
• purple or brownish-red skin spots, or skin sores
• signs of a severe allergic reaction (such as difficulty breathing, hives, swelling of the face or throat)
• signs of hypersensitivity syndrome (e.g., fever or chills, flu-like symptoms [e.g., sore throat, cough, runny nose], swollen lymph nodes, yellowing of the eyes or skin)
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort
• symptoms of endocarditis (infection of the heart muscle; fever, chills, fatigue, night sweats, shortness of breath, tiny purple or red spots on the skin)

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.

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 use this medication.

Allergic reactions: In rare cases, a severe allergic reaction called Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS syndrome) may occur. This reaction may include fever, swollen glands, yellowing of the skin or eyes, flu-like symptoms with skin rash or blistering, or effects on other organs. These reactions are medical emergencies. Get immediate medical attention if you have symptoms of a severe allergic reaction.

Calcium and vitamin D: While using this medication, you need to receive enough calcium and vitamin D to maintain blood calcium levels. Your doctor will recommend a dose of calcium and vitamin D based on your needs. Contact your doctor immediately or get immediate medical attention if you develop symptoms of low blood calcium levels while using this medication (muscle spasms, twitches, or cramps; numbness or tingling in the fingers, toes, or around the mouth).

Fractures: As with other medications in this class, denosumab may contribute to a type of rare fracture of the long bone in the thigh (femur) without any form of trauma. If you experience new or unusual pain in the groin, hip, or thigh area, contact your doctor as soon as possible. Fractures of the bones in the spine (vertebra) have been reported after stopping this medication. Do not stop treatment with this medication without checking with your doctor first.  

Infections: This medication may cause infections that in some cases are serious and require hospitalization. Contact your doctor at once if you develop signs of an infection such as fever, abdominal pain, earache, painful urination, or blood in urine, or if you notice a red, swollen, or tender area on the skin. People who are taking medications that suppress the immune system (e.g., tacrolimus, prednisone, azathioprine, anticancer medications) or who have a suppressed immune system may be more at risk of developing infections.

Severe jawbone problems: Denosumab may cause problems with your upper and or lower jaw. You may be at a higher risk of these problems if you have cancer that has spread to the bones, are taking certain medications (e.g., prednisone, anticancer medications), are having radiation treatments, have poor oral hygiene, or are having a tooth extracted. Your doctor may recommend that you see a dentist before starting this medication. It is important to practice good oral hygiene while taking this medication.

Pregnancy: Denosumab is only recommended for postmenopausal people and has not been studied for use during pregnancy. Anyone who could become pregnant must use highly effective birth control measures while taking this medication and for at least 5 months after the last dose of denosumab, to avoid becoming pregnant while using this medication. If you become pregnant while using this medication, contact your doctor immediately.

Breast-feeding: Denosumab has not been studied for use by people who are breast-feeding. It is not known if denosumab passes into breast milk. If you are breast-feeding and are taking this medication, it may affect your baby. Denosumab is not recommended for use by people who are breast-feeding.

Children and adolescents: The safety and effectiveness of using this medication have not been established for children.

For a full list of interactions, use the Drug Interaction Checker available on the Drugs.com website.

If you are taking other 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.

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.