Panitumumab (Intravenous)

Overview

Panitumumab belongs to a family of drugs called monoclonal antibodies. This medication is sometimes given by itself, but it is sometimes combined with other drugs that help prevent the cancer from spreading to other parts of the body.

This medication works by preventing the cancer cells from growing. Cancer cells have receptors on the surface of the cells called EGFRs, or epidermal growth factor receptors. When these receptors are triggered, they cause the cancer cells to grow. Panitumumab attaches to the EGFRs and blocks them. This limits the growth of the cancer cell. The more EGRFs there are on the surface of the cancer cell, the more effective panitumumab will be in reducing the growth of the cells.

However, panitumumab can also prevent the growth of normal, non-cancer cells. This can trigger a range of potential side effects, some of which are unpleasant but not harmful over the long-term, while others are more serious and will need medical attention.

Before being given this medication, you must receive a KRAS gene mutation test, which helps doctors determine whether this will be an effective treatment for you. The drug will only take effect on cancer cells which have a normal KRAS gene. If the cancer cells have the mutation in the KRAS gene, the medication will not be effective.

This medication will only be administered by a doctor, nurse, or other medical professional.

Conditions Treated

  • Colon cancer

Type Of Medicine

  • Monoclonal antibody

Side Effects

Panitumumab can cause undesired side effects in some people who take it. Potential side effects are listed below.

Skin problems

Some individuals experience skin problems, such as rashes, hives, redness, itching or lesions. These may lead to infections that can be serious and, in some cases, even life-threatening. See your doctor straight away if you notice any skin problems while you are taking panitumumab.

Breathing problems

See your doctor immediately if you experience any breathing problems, including shortness of breath, heaviness or tightness in the chest or wheezing.

Vision problems

If you notice any vision problems, including blurred vision, difficulty focusing, difficulty reading or any other changes in your vision, see your doctor straight away.

Electrolyte imbalance

Panitumumab can cause certain electrolytes to be excreted from your body at a higher than normal rate, including magnesium, potassium or calcium. Consult your doctor without delay if you notice any of the following symptoms:

  • Bloating or swelling, especially in the face, arms, hands, ankles or feet

Other common side effects

You may also experience some of the following side effects. If you do, consult the doctor or nurse:

  • Anxiety

This is not an exhaustive list and you may experience other side effects that are not listed here. Pay attention to how this medication is affecting your body, and inform your doctor if you notice any side effects.

Depending on the side effects that you experience, your doctor may wish to lower your dose of panitumumab or increase the time period between doses. Your doctor will make this assessment by balancing the beneficial effects that the medication gives you with the harmful effects that it may be causing.

Allergic reaction

Panitumumab can cause a type of allergic reaction called an infusion reaction. You may be given another medication at the same time as panitumumab to reduce the risk of this happening. This reaction can occur for up to an hour after the infusion of the drug has been completed. You will usually be told to remain in the clinic for at least an hour after your first treatment, so that your doctor can observe how your body has tolerated the medication.

When you are being given this medication and while you are still in the clinic after the infusion has finished, tell the doctor or nurse on-duty immediately if you notice any of the following:

  • Chills

Dosage

The dose you receive will depend upon the severity of your condition, as well as other factors, such as your bodyweight. However, the typical dose is as follows: 6 mg per kg of body weight, given gradually over the course of an hour.

For people who tolerate their first treatment without serious adverse reactions, the period of the infusion may be reduced to around 30 minutes. Some people will be given a larger than normal dose. If the total dose to be administered exceeds 1000 mg, the dose would be administered over 90 minutes.

This dose is typically repeated every 14 days. You will be given your dose of panitumumab in a hospital, cancer treatment clinic or other appropriate facility by trained medical professionals. The dose will be administered into the veins of one of your arms with a needle.

Panitumumab must be released into your body slowly, so you will remain with the needle in your arm for around an hour. As the drug enters your body, you may find that you feel some nausea. Your doctor may give you other medications to help reduce this effect.

Make sure you attend all of the appointments you have been set to receive the medication. If you are unable to attend one of the appointments, inform your doctor immediately so that they can make alternative arrangements.

Interactions

Panitumumab can interact with some other medications in ways that produce adverse side effects. Before you are given this medication, you should discuss with your doctor any medications, vitamins or other supplements that you are taking. The drugs listed below are of particular concern:

  • Aspirin

Alcohol

Alcohol increases your risk of side effects. You should not consume alcohol while you are taking panitumumab.

Warnings

Avoid exposure to sunlight while you are taking this medication. Wear sunscreen while outdoors in direct sunlight, and wear protective clothing, such as long-sleeves and hats. Continue this for two months after you have finished your treatment with panitumumab.

This medication may cause drowsiness, affect your vision or affect your ability to concentrate. Do not drive or operate machinery until you have seen how the medication affects you and you are sure that it is safe to do so.

If you receive any other medical or dental treatment while you are taking this medication, let the doctors, dentists or nurses know that you are taking panitumumab.

Panitumumab is a potent medication that is known to produce side effects. For some people, it will not be safe to use at all. For others, they will be able to use it with caution, and greater care must be taken to minimize the risk of unwanted side effects. Your doctor may make the decision to not prescribe other medication at the same time, for example.

Other medical conditions

Panitumumab may make the symptoms of some other medical conditions worse. You should tell your doctor about any other medical conditions that you presently have, so that they can determine whether this medication is safe for you to use. The following conditions are of particular concern:

  • Dehydration

You should also let your doctor know if you have previously suffered from any of these conditions. If that is the case, you may still be able to take panitumumab, but your doctor may want to adjust the dose, or they might want you to come in for more frequent check-ups to make sure that no unwanted side effects are occurring.

Pregnancy

This medication should be avoided during pregnancy. As noted earlier, panitumumab functions by inhibiting receptors called EGFRs. These receptors are responsible for making some cancer cells grow, but they are also involved in the normal growth of the fetus during pregnancy. Panitumumab can also cause magnesium wasting (larger amounts of magnesium being excreted from the urine than normal), which can also be dangerous for the unborn baby.

You should ensure that you are using two effective forms of birth control while you are taking this medication. If you become pregnant during your course of treatment, consult your doctor as soon as possible.

Breastfeeding

There is a risk that panitumumab can enter the breast milk and, therefore, potentially be passed to the infant. You will likely be advised by your doctor to cease breastfeeding during the course of your treatment with this drug and for two months after you have finished your treatment. This will ensure that the drug has left your system and you will be safe to breastfeed again.

Children

The safety of this medication when given to children has not yet been established. Your doctor will give you more advice on whether panitumumab is suitable to be given to your children.

Older people

According to research conducted so far, older individuals are somewhat more likely to experience side effects, such as diarrhea, as a result of taking panitumumab.

Storage

Panitumumab will be given to you by a nurse or doctor in a hospital, cancer treatment clinic or other facility. You will not be given any of this medication to take home and use yourself.

Panitumumab should be stored in a refrigerator. It should be kept away from sources of heat, moisture and direct sunlight. Do not freeze this medication. Store panitumumab in its original packaging, which will protect it from light, and keep it out of the sight and reach of children.

If the medication has passed its expiry date, it should be disposed of safely. Do not dispose of the medication by flushing it down the toilet or throwing it into the trash.

Summary

Panitumumab is a drug given to patients with advanced cancer in the bowel or rectum. It works by interfering with the ability of the cancer cells to grow, and the cells are eventually destroyed by your body.

The medication also prevents some normal, non-cancerous cells from growing. Because of this, panitumumab can cause a range of side effects, ranging from minor complaints, such as skin rashes, to more serious side effects that may require urgent medical care.

Due to its potential to produce side effects, this medication will only be administered by a medical professional in an appropriate setting. You will not be given this medication to take home with you to administer yourself.