Panitumumab is used to treat colorectal cancer. This is a type of medicine called humanised monoclonal antibody that binds to a certain protein (epidermal growth factor receptor-EGFR). Panitumumab helps stops or slows the growth of cancer cells.

Colorectal cancer starts in the colon or the rectum. Cancer starts when cells in the body start to grow out of control. Cells in nearly any part of the body can become cancer and can spread to other areas of the body. Most colorectal cancers start as a growth on the inner lining of the colon or rectum. These growths are called polyps. Some types of polyps can change into cancer over time, but not all polyps become cancer. The chance of a polyp changing into cancer depends on the type of polyp it is. If cancer forms in a polyp, it can grow into the wall of the colon or rectum over time. The wall of the colon and rectum is made up of many layers. Colorectal cancer starts in the innermost layer and can grow outward through some or all of the other layers.
When cancer cells are in the wall, they can then grow into blood vessels or lymph vessels. From there, they can travel to nearby lymph nodes or to distant parts of the body.
Signs and symptoms of colon cancer include:

• Rectal bleeding or blood in your stool
• A persistent change in your bowel habits, including diarrhea or constipation or a change in the consistency of your stool
• A feeling that your bowel doesn’t empty completely
• Persistent abdominal discomfort, such as cramps, gas or pain
• Unexplained weight loss
• Weakness or fatigue
  Many people with colon cancer experience no symptoms in the early stages of the disease.
  In general, colon cancer begins when healthy cells in the colon develop changes in their DNA. A cell’s DNA contains a set of instructions that tell a cell what to do. Healthy cells grow and divide in an orderly way to keep your body functioning normally. But when a cell’s DNA is damaged and becomes cancerous, cells continue to divide — even when new cells aren’t needed. As the cells accumulate, they form a tumor. With time, the cancer cells can grow to invade and destroy normal tissue nearby. And cancerous cells can travel to other parts of the body to form deposits there.
  Factors that may increase your risk of colon cancer include:
  Older age – Colon cancer can be diagnosed at any age, but a majority of people with colon cancer are older than 50. The rates of colon cancer in people younger than 50 have been increasing, but doctors aren’t sure why.
  Diabetes – People with diabetes or insulin resistance have an increased risk of colon cancer.
  Obesity – People who are obese have an increased risk of colon cancer and an increased risk of dying of colon cancer when compared with people considered normal weight.
  Smoking – People who smoke may have an increased risk of colon cancer.
  Alcohol – Heavy use of alcohol increases your risk of colon cancer.
  Radiation therapy for cancer. Radiation therapy directed at the abdomen to treat previous cancers increases the risk of colon cancer.

How does the medicine work?
Many cancer cells have structures called epidermal growth factor receptors (EGFRs) on their surfaces. These receptors allow a protein called epidermal growth factor (EGF) to attach to the cells. When the epidermal growth factor attaches to the receptor, this stimulates the growth and multiplication of the cancer cells.

Panitumumab works by specifically recognizing, binding to, and blocking the EGFRs on cancer cells. This stops the cancer cells receiving the messages they need to grow, multiply and spread, and causes the cancer cells to die.

How to use this medicine?
Panitumumab is given as a drip into a vein or also called intravenous infusion once every two weeks. It is not used in combination with other chemotherapy treatments. The recommended infusion time is about 60 minutes, but this may be increased to 90 minutes. It is if higher amounts of Panitumumab are administered.

Take this prescription exactly as given by your doctor. Do not suddenly stop this unless you a consent from your doctor. Stopping the medication suddenly might cause the condition to get worse or might develop other conditions.

What are the side effects of the medicine?
Common side effects:

• Vomiting
• Diarrhea
• Nausea
• Constipation
• Tiredness
• Growth of eyelashes
• Stomach or abdominal pain
• Skin reactions (acne, redness, itching, or rash)
  Call your doctor at once if you have:
• Severe or ongoing diarrhea
• Sudden chest pain or discomfort
• Wheezing
• Dry cough or hack
• Feeling short of breath
• Redness , swelling, or irritation of your eyes or eyelids
• Vision changes
• Swelling in your face
• Dehydration symptoms (feeling very thirsty or hot, heavy sweating, being unable to urinate, or hot and dry skin)
• Signs of a kidney problem (little or no urinating, painful or difficult urination, or swelling in your feet or ankles)
• Skin problems (severe or worsening acne, dryness, skin itching, redness, cracking, peeling, or oozing

Warnings and Precautions

• This medicine may affect the ability of a woman to get pregnant. You should discuss fertility with your doctor before treatment with this medicine is started.
• You will need to have a blood test to monitor the level of magnesium and calcium in your blood every two weeks during treatment with this medicine. If this level is too low, magnesium or calcium supplements may be required. The level of magnesium and calcium in your blood will also need to be checked eight weeks after treatment is stopped.
• Use this with caution in people on a low salt diet.
• This is not recommended for use in people with thickening and stiffening of the lungs, with inflammation of the lungs, and in children and adolescents less than 18 years of age.
• This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
• Let your doctor know if you are pregnant, breastfeeding, or planning to become pregnant before taking this medicine.