Actemra Side Effects: What to Expect and When to Call Your Doctor

Actemra (tocilizumab) is a powerful biologic medication that suppresses an overactive immune system. That mechanism is what makes it effective against rheumatoid arthritis, giant cell arteritis, and other inflammatory diseases — but it also means your immune system has less capacity to fight infections and other threats. Understanding Actemra's side effects helps you know what's normal, what needs monitoring, and what requires an immediate call to your doctor.

Boxed Warning: Serious Infections

Actemra carries a FDA Boxed Warning — the most serious warning the FDA issues — about the risk of serious infections that may lead to hospitalization or death. Actemra suppresses the immune response, which can allow bacteria, viruses, and fungi that your body would normally keep in check to cause serious illness.

Infections of concern include:

• Active tuberculosis (TB) — which may present as pulmonary or extrapulmonary disease. All patients must be tested for latent TB before starting Actemra and treated if positive.
• Invasive fungal infections (candidiasis, aspergillosis, pneumocystis)
• Bacterial infections, including severe pneumonia and sepsis

Call your doctor immediately if you develop: fever, chills, cough, shortness of breath, burning with urination, or any new wound that is red, warm, or draining.

Common Side Effects

These side effects are reported frequently in clinical trials and are typically manageable:

• Upper respiratory tract infections: Cold symptoms, sinus infections, and sore throat are the most commonly reported side effects
• Nasopharyngitis: Runny nose, congestion, and mild sore throat
• Headache: Reported in some patients, especially early in treatment
• Hypertension (high blood pressure): Monitor blood pressure regularly during treatment
• Elevated liver enzymes (ALT/AST): Routine liver function tests are required; dose adjustments may be needed if levels rise significantly
• Neutropenia (low white blood cell count): Reduced ability to fight bacteria; CBC monitoring is required
• Injection site reactions (SC only): Redness, pain, or swelling at the injection site; more common with SC than IV

Serious Side Effects to Know About

These are less common but require immediate medical attention:

• GI perforation (bowel perforation): A rare but serious complication. Most common in patients who also take NSAIDs, corticosteroids, or methotrexate, and in those with a history of diverticulitis. Report new or worsening stomach pain, bloody stool, or significant changes in bowel habits immediately.
• Serious hepatotoxicity (liver damage): Rare cases of serious liver problems, including need for transplant, have been reported. Routine LFT monitoring is critical.
• Elevated cholesterol: Actemra can increase LDL and total cholesterol. Lipid panels should be checked 4–8 weeks after starting, then per standard care guidelines.
• Severe hypersensitivity or anaphylaxis: Rare allergic reactions to IV infusions can occur. Symptoms include hives, difficulty breathing, and low blood pressure.

Monitoring Schedule: What Labs Are Required?

Your doctor will monitor you regularly while you take Actemra. A typical monitoring schedule includes:

• CBC (complete blood count) — before each IV infusion; regularly for SC users
• Liver function tests (ALT/AST) — at baseline, then regularly per your provider's protocol
• Lipid panel — at 4–8 weeks after starting, then annually or as needed
• TB screening — before starting Actemra and periodically during therapy if at risk

For information on how Actemra interacts with other medications, see our guide to Actemra drug interactions. If you're having trouble finding Actemra at a pharmacy, medfinder can help.