• Before starting an injected biologic for axial spondyloarthritis (axSpA), you will undergo blood tests and be screened for infections.
• Biologics are taken either as an intravenous (IV) infusion in a clinic or a self-injection under the skin at home. Schedules for injections vary.
• It’s important to know how to recognize and manage potential side effects and when you might expect to notice improvement in your symptoms.

Axial spondyloarthritis is an umbrella term for several types of inflammatory arthritis — including ankylosing spondylitis and psoriatic arthritis — that affect the spine. Biologic drugs are injected medications that target the immune system proteins involved with inflammation in axSpA. Biologic therapy may be appropriate for people with spondylitis when treatment options such as nonsteroidal anti-inflammatory drugs (NSAIDs) or conventional disease-modifying antirheumatic drugs (DMARDs) like methotrexate or sulfasalazine (Azulfidine) have not provided adequate relief from symptoms.

Read more about conventional versus biologic DMARDs for spondylitis.

If you are considering starting an injected biologic to treat your spondylitis, you might be wondering what to expect in terms of screening, how biologics are injected, potential side effects, and when you might notice improvement. To help you get informed and prepared, here are answers to five common questions.

1. What Screening Tests Will You Need First?

Your doctor will order various tests before starting you on an injectable biologic drug. Biologic drugs suppress aspects of the immune system, which causes an increased risk of infection. For this reason you will need to be screened for any “silent” infections for which you might not have symptoms. If you have an existing infection, it will usually need to be treated before beginning biologic treatment.​

You will likely need blood tests to screen for:

• Tuberculosis (TB), possibly with a chest X-ray and skin test
• Hepatitis B and hepatitis C

Additional blood tests will establish baseline levels that will be monitored for abnormalities while you are taking a biologic. Baseline tests typically include:

• A liver enzyme test to measures liver function
• A complete blood count to measure red blood cells, white blood cells, hemoglobin, hematocrit, and platelets
• Levels of lipids, or blood fats such as cholesterol, due to the risk for heart disease

These screening tests help ensure your safety and health while taking the injected medication.

2. How Will Your Treatment Be Injected?

Several types of biologic drugs are used in the treatment of spondylitis. The method of administration, dosage, and scheduling can vary depending on the drug. Your rheumatologist and health care team will discuss the proper usage of any biologic drug recommended for you.

Biologic Drug Injections

Biologic drugs consist of complex proteins that cannot be effectively absorbed in the digestive system if taken orally. Currently, they must be taken by IV infusion or subcutaneous (under the skin) injection.

IV infusions are given in a clinical setting by health care providers through a needle inserted into a vein. Subcutaneous injections are self-administered at home using prefilled syringes and auto-injectors that release the drug under the skin. If you’re going to self-inject your biologic at home, make sure your doctor or nurse gives you training on how and where to inject. Ask as many questions as you need to. You should be able to do your first self-injection at the clinic, supervised by your health care provider.​

Read more about intravenous infusion versus subcutaneous self-injection.

Dosing of Biologic Drugs

Dosage for biologic drugs typically begins with more frequent loading doses and then tapers down. Loading doses and schedules can vary among medications.

3. How Often Will You Need Injections?

Biologic drugs are administered on a variety of schedules. In some cases, higher doses may be given less frequently by infusion, while self-injected drugs with lower doses might be taken more often.

Be sure to discuss scheduling in detail with your rheumatologist. It’s essential that you thoroughly understand your treatment plan and carefully adhere to the specific schedule to get the most benefit from the drug.

4. What Side Effects Could You Experience?

When taking a biologic drug, you have a higher risk of developing an infection. This is because biologic medication is designed to suppress specific aspects of the immune system that cause chronic inflammation in people with spondylitis.

Other common side effects for biologics include reactions at the injection site, headache, and nausea. Talk with your doctor to get medical advice on how to best manage common side effects.

Signs of serious infection should be reported to your rheumatologist and health care providers immediately. Tell your doctor if you experience any of the following symptoms:

• Fever or chills
• Shortness of breath
• Muscle pain or tingling
• Rash or painful sores
• Diarrhea or abdominal pain
• Abnormal urination

5. When Will It Start Working?

Injected biologic drugs may take time to start taking effect. Some people with spondylitis might feel better after their first treatment. But more often than not, biologic drugs can take several weeks or months to take effect. When taking biologic drugs, it’s important to maintain treatment and be patient as the medication starts to work. Talk with your doctor about when you might expect to notice improvement in back pain, joint pain, uveitis (eye inflammation), and other symptoms of spondylitis.

Talk With Others Who Understand

On MySpondylitisTeam, the social network for people with spondylitis and their loved ones, more than 87,000 members come together to ask questions, give advice, and share their stories with others who understand life with spondylitis.

Do you have other questions about injected biologic treatment? Share your experience in the comments below, or start a conversation by posting on your Activities page.