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Does Cosentyx weaken the immune system?

Medically reviewed by Carmen Pope, BPharm. Last updated on Nov 3, 2023.

Official answer


The biologic drug Cosentyx (secukinumab) can weaken your immune system, increasing your risk of infection. Two of the most common adverse reactions to the drug were colds and upper respiratory tract infections in clinical trials, but this occurred in less than 1% of people.

Approved to treat psoriasis, psoriatic arthritis, hidradenitis suppurativa, and inflammatory forms of spinal arthritis, Cosentyx blocks Interleukin-17A, an immune system protein that fuels inflammation. Blocking this protein can lower your immune system’s ability to fight off infections.

In one study, 848 people with psoriasis who took secukinumab showed a slightly higher risk of respiratory and urinary tract infections than their counterparts who took another biologic drug to treat psoriasis.

Because Cosentyx and other biologic drugs increase your risk for infection, patients are tested for tuberculosis (TB) before initiating treatment. It is important to watch out for any signs and symptoms of this bacterial lung disease while taking Cosentyx. Some individuals are treated for TB before starting Cosentyx therapy if they are considered to be at high risk for this infection. Cosentyx should not be used if you have active TB.

Other contraindications to Cosentyx include:

  • Any active infection
  • An infection that doesn’t go away or that keeps returning
  • Close contact with someone with active TB

Any symptoms suggestive of infection must be taken seriously while on Cosentyx.

These can include:

  • Fever
  • Sweats
  • Chills
  • Muscle aches
  • Cough
  • Shortness of breath
  • Blood in phlegm
  • Unexplained weight loss
  • Warm, red or painful skin or sores
  • Diarrhea
  • Stomach pain
  • Burning during urination
  1. Novartis. Cosentyx Product Label. Updated 10/2023. Available at:
  2. Srinivas C, Odsbu I, Linder M. Risk of common infections among individuals with psoriasis in Sweden: A nationwide cohort study comparing secukinumab to ustekinumab. Pharmacoepidemiology and Drug Safety. 2020;29:1562-1569.

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