This medication belongs to a family of medications known as biological response modifiers ("biologics") or TNF blockers. It is used alone or in combination with another medication, methotrexate, to treat moderately-to-severely active rheumatoid arthritis (RA). Certolizumab pegol is also used alone or in combination with methotrexate to treat moderately-to-severely active psoriatic arthritis (PsA) when other disease-modifying medications have not worked. For both conditions, it may be used alone if methotrexate is not tolerated. Certolizumab pegol may be used to treat ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA) that has not responded to other treatments. It may also be used to treat adults with plaque psoriasis (PsO) for whom systemic (internal) treatment is appropriate.

For people with the immune conditions, their bodies overproduce a protein called tumour necrosis factor (TNF), which causes pain, inflammation, and damage. Certolizumab pegol blocks the production of TNF and decreases the inflammation in the joints.

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.

Certolizumab pegol is given by subcutaneous (under the skin) injection usually in the front of the thigh or abdomen. The usual starting dose is 400 mg (2 injections of 200 mg, given at the same time in different areas of the body) at weeks 0, 2, and 4. After this, the usual dose is 200 mg every other week. Some people may eventually use 400 mg every 4 weeks except in the case of plaque psoriasis, where the usual maintenance dose is 200 mg every 2 weeks.

Certolizumab pegol is used with the guidance and supervision of a doctor. Your doctor or nurse will assist you in the preparation and injection of your first dose (or first few doses) and can teach you how to give yourself the injection at home. Do not attempt to inject this medication on your own until you completely understand how to inject a dose. If you are unsure of how to prepare or administer a dose, ask a health care professional to clarify for you. If you are having difficulty giving yourself injections, ask a family member or other caregiver for help if they are willing to become involved with your treatment and are willing to learn how to give you your injections.

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 prescribed by your doctor. If you miss a dose and your next dose is not for another 7 days (i.e., one week) or longer, take it as soon as possible and continue with your regular schedule. If the next dose is due within one week (i.e., less than 7 days), skip the missed dose and continue with your regular dosing schedule. Do not administer a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Before injecting the medication, check the solution to ensure that it is clear, colourless, and has no particles in it. If the solution is not clear and colourless, discard the syringe safely and use a new one.

Store this medication in the refrigerator, protect it from light, and keep it out of the reach of children. Do not freeze. If necessary, this medication may be stored at room temperature, protected from light, just one time, for up to 10 days.

Prefilled Syringe
Each mL of sterile, preservative-free, clear and colourless-to-pale-yellow solution contains 200 mg of certolizumab pegol. Nonmedicinal ingredients: 1.36 mg of sodium acetate, 7.31 mg of sodium chloride, and water for injection USP. The syringe components do not contain any latex or dry natural rubber, however the needle shield inside the removable cap contains a derivative of natural rubber latex.

Prefilled Autoinjector
Each mL of sterile, preservative-free, clear and colourless-to-pale-yellow solution contains 200 mg of certolizumab pegol. Nonmedicinal ingredients: 1.36 mg of sodium acetate, 7.31 mg of sodium chloride, and water for injection USP. The autoinjector components do not contain any latex or dry natural rubber, however the needle shield inside the removable cap contains a derivative of natural rubber latex.

Do not use certolizumab pegol if you:

• are allergic to certolizumab pegol or any ingredients of the medication
• have a serious infection such as sepsis (an infection in the bloodstream), active tuberculosis, an abscess, or an opportunistic infection (a type of infection that affects people with weakened immune systems)
• have moderate-to-severe heart failure

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.

• dizziness
• rash
• redness, pain, swelling, itching, warmth, and bruising at the injection site
• tiredness

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

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

• flu-like symptoms (sudden lack of energy, fever, cough, sore throat)
• itchy, reddish purple skin rash and/or threadlike white-grey lines on mucous membranes
• symptoms of heart failure (shortness of breath or swelling of the feet or legs)
• symptoms of lupus (rash on the cheeks or other body areas; sun sensitivity; joint or muscle pain; fatigue; chest pain; shortness of breath; or swelling of the feet, ankles, or legs)
• symptoms of nervous system problems (such as arm or leg weakness, vision changes, dizziness, or numbness or tingling in any part of the body)
• symptoms of shingles (herpes zoster infection; e.g., pain, burning, numbness, or tingling to areas of the skin on one side of the body; sensitivity to touch; red rash; itching; fluid-filled blisters)

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

• symptoms of a serious allergic reaction (e.g., hives, face swelling, difficulty breathing or swallowing)
• symptoms of a serious infection (e.g., fever, chills, headache, flu-like symptoms, feeling tired, cough, blood in sputum, shortness of breath, night sweats, weight loss, nausea or vomiting, diarrhea, joint swelling, cold sores, tooth pain, new or worsening pain in any part of the body)

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 taking 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 take this medication.

Anemia: Certolizumab pegol may cause low levels of red blood cells. If you experience symptoms of reduced red blood cell count (anemia) such as shortness of breath, feeling unusually tired, or pale skin, contact your doctor as soon as possible.

Your doctor will do blood tests regularly to monitor the number of specific types of blood cells, including red blood cells, in your blood.

Bleeding: This medication may affect your body's ability to produce enough of certain types of blood cells, including the ones that help you stop bleeding. If your experience unusual bruising or bleeding, increased nosebleeds, bleeding gums, or you notice blood in your urine, contact your doctor as soon as possible. If you notice signs of bleeding in the stomach such as bloody, black, or tarry stools, or vomiting blood or material that looks like coffee grounds, get medical attention immediately.

If you have an increased risk of bleeding, your doctor should closely monitor your blood counts while you are using this medication.

Cancer: Rarely, cases of cancer (including skin cancer, leukemia [blood cancer], and lymphoma) have been reported among people taking this medication. Talk to your doctor about cancer screening and your risk of cancer, and see your doctor if you have a bump or sore that does not heal.

Congestive heart failure (CHF): People taking medications in the same family as certolizumab pegol may develop CHF or find that their CHF gets worse. If you have a history of CHF or are at risk of developing CHF, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Tell your doctor if you have CHF. If you develop shortness of breath or swelling of the legs or feet (symptoms of CHF), contact your doctor right away.

Dizziness: Certolizumab pegol may affect the mental or physical abilities needed to drive or operate machinery. Avoid driving, operating machinery, or performing other potentially hazardous tasks until you have determined how you are affected by this medication.

Hepatitis B: Certolizumab pegol, like other tumour necrosis factor blockers, has been associated with reactivation of hepatitis B infections, which can be fatal. If you have a history of hepatitis B infections, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Immune system problems: Rarely, people taking medications in the same family as certolizumab pegol may develop symptoms similar to the symptoms of lupus (rash on the cheeks or other body areas; sun sensitivity; joint or muscle pain; fatigue; chest pain; shortness of breath; or swelling of the feet, ankles, or legs). Contact your doctor if you develop these symptoms.

Laboratory tests: This medication may interfere with certain laboratory tests. If you are scheduled for lab tests, let your doctor know that you are using certolizumab pegol.

Liver function: People taking certolizumab pegol may have changes in liver function that produce abnormal liver test results. Your doctor will recommend regular liver tests while you are taking this medication.

Neurological effects: Rarely, people taking medications in the same family as certolizumab pegol may develop nervous system diseases such as multiple sclerosis (MS). Contact your doctor right away if you notice vision changes, dizziness, arm or leg weakness, and numbness or tingling in any part of your body.

Serious infections: Certolizumab pegol can affect the way your body's natural defences work to fight infection. This makes the body more likely to develop infections due to bacteria, viruses, and fungi. This effect is increased if you are taking certolizumab with other medications that reduce the body's ability to fight infection. For some people, these infections have been fatal.

If you have a history of chronic or frequent infections, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Stop taking the medication and tell your doctor right away if you notice symptoms of a serious infection, such as fever, chills, headache, flu-like symptoms, feeling tired, cough, blood in the sputum, shortness of breath, night sweats, weight loss, nausea, vomiting, diarrhea, frequency or burning while passing urine, redness or swelling of skin or joint, cold sores, tooth pain, and new or worsening pain in any part of the body.

Severe allergy: Certolizumab pegol is known to cause severe allergic reactions. Contact your doctor immediately if you experience signs of an allergic reaction, such as skin rash, itching, difficulty breathing, or swelling of the face and throat.

Surgery: If you have surgery planned, let your surgeon and other health care professionals know that you are taking certolizumab pegol.

Tuberculosis: Some people who have had tuberculosis (a lung infection) in the past have had this infection return when they are using certolizumab pegol. If you have a history of tuberculosis, or have come into recent contact with someone who has tuberculosis, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Vaccinations: People taking this medication should not receive certain vaccines. Talk to your doctor about whether any vaccines you are scheduled to take may be used with this medication.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. Women who may become pregnant while using this medication should use effective birth control while using certolizumab pegol and for 5 months after the last dose. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if certolizumab pegol passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

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

There may be an interaction between certolizumab pegol and any of the following:

• BCG
• denosumab
• echinacea
• fingolimod
• immunosuppressants (e.g., cyclosporine, mycophenolate, pimecrolimus, tacrolimus)
• leflunomide
• lenalidomide
• medications that weaken the immune system (e.g., medications for cancer or organ transplants)
• other biologics (e.g., abatacept, adalimumab, etanercept, golimumab, infliximab, anakinra, rituximab, sarilumab, tocilizumab, tofacitinib)
• roflumilast
• siponimod
• vaccines

If you are taking any of these 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.

Medications other than those listed above may interact with this medication. 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.