Denosumab is a type of medicine called a human monoclonal antibody. This is used for the breakdown of the bone. Denosumab is prescribed for the treatment of osteoporosis in women who have passed menopause and prostate cancer in men at high risk of breaking a bone. 

Osteoporosis is a condition that affects men and women of all races. This can cause bones to become weak and brittle. Osteoporosis-related fractures most commonly occur in the wrist, spine, or hip. Bone is living tissue that is constantly being broken down and replaced. Osteoporosis happens when the creation of new bone doesn’t keep up with the loss of old bone. There typically are no symptoms in the early stages of bone loss. But once your bones have been weakened by osteoporosis, you might have signs and symptoms that include:

  • A stooped posture
  • Loss of height over time
  • A bone that breaks much more easily than expected
  • Back pain caused by a fractured or collapsed vertebra

Your bones are in a constant state of renewal. The new bone is made and old bone is broken down. When you’re young, your body makes new bone faster than it breaks down old bone, and your bone mass increases. After the early 20s, this process slows and most people reach their peak bone mass by age 30. As people age, bone mass is lost faster than it’s created.

Prostate cancer happens in the prostate which is a small walnut-shaped gland in men that creates the seminal fluid. Prostate cancer is one of the most common types of cancer in men. Usually, prostate cancer grows slowly and is initially confined to the prostate gland, where it may not cause serious harm. However, while some types of prostate cancer grow slowly and may need minimal or even no treatment, other types are aggressive and can spread quickly. More advanced prostate cancer may cause signs and symptoms such as:

  • Trouble urinating
  • Blood in semen
  • Decreased force in the stream of urine
  • Discomfort in the pelvic area
  • Erectile dysfunction
  • Bone pain

How does Denosumab work?

The bone is not a static structure. It is continually reformed and rebuilt by cells called osteoclasts and osteoblasts. These cells continuously deposit and remove calcium and phosphorous. It is stored in a protein network that makes up the structure of the bone. Old bone is broken down by the osteoclasts and new bone is formed by the osteoblasts.

In menopausal women, blood levels of the female hormone estrogen start to decrease. This results in an increase in the breakdown of bone by the osteoclasts, which can lead to a loss of bone density. Bone loss is particularly rapid for the first ten years after menopause and it may lead to the development of osteoporosis. Osteoporosis can also occur in men, particularly in men having treatment for prostate cancer. The treatments work by reducing the amount of testosterone in the blood, which has a similar effect on bone in men to reduced estrogen levels in women.

Denosumab works by recognizing and binding to a specific protein that normally activates the osteoclasts. By binding to this protein, Denosumab stops it from activating the osteoclasts. This prevents the development, activity, and survival of the osteoclasts and so stops them from breaking down bone. This helps to keep the bones strong and less likely to break. In postmenopausal women, this medicine has been shown to reduce the risk of spinal, non-spinal, and hip fractures. In men, this medicine has been shown to reduce the risk of spinal fractures.

How to use it?

Your doctor will inject this medicine under your skin in the upper thigh, upper arm, or abdomen as directed. Usually, it is given every 6 months. This medication is used regularly for its better benefit. It is important to keep receiving this medicine even if you feel well. Most people with osteoporosis do not have symptoms. Remember to take this every 6 months. Continue to take other medications for your condition as directed by your doctor. 

The dosage is based on your medical condition, age, and response to the treatment. If you missed a dose, contact your doctor right away for instructions. Inform your doctor at once if your condition does not improve or if it gets worse. 

What are the side effects?

Common side effects:

  • Weakness
  • Tiredness
  • Back pain
  • Headache
  • Diarrhea
  • Joint pain
  • Nausea

Call your doctor right away if you have the following side effects:

  • Shortness of breath
  • New or unusual hip, thigh, or groin pain
  • Jaw pain
  • Joint, bone, or muscle pain

Let your doctor know at once and call for medical help if you have signs of an allergic reaction:

  • Difficulty breathing
  • Hives or itching
  • Swelling of your mouth, tongue, face, or throat

Warnings and Precautions

  • This medicine may cause serious infections of the abdomen, skin, bladder, or ear. Tell your doctor instantly if you experience any of the following symptoms (chills, redness or swelling of the skin, fever, severe abdominal pain or pain passing urine)
  • As this medicine slows bone breakdown, it prevents calcium from being reabsorbed from the bones into the blood. This can cause the amount of calcium in your blood to fall to a low level. Your doctor will usually ask you to take calcium and vitamin D to prevent this. Your doctor may also want you to have regular blood tests to monitor the level of calcium in your blood. 
  • This should be used with caution in smokers, people with poor oral hygiene, or any current or recent problems with their mouth or teeth, with cancer, or with anemia or blood clotting problems.
  • People with infections and with severely decreased kidney function, this medicine should also be used with caution. 
  • This should not be used in people with a low level of calcium in their blood or with rare hereditary problems of fructose intolerance. 
  • This medicine is not recommended for children and adolescents under 18 years of age.
  • Inform your doctor if you ever had an allergic reaction to this drug or if you have any allergies.