Cosentyx (secukinumab) can cause side effects that change over time. Some are more likely to show up soon after starting treatment, while others may appear later or persist. Here’s a practical overview:
- Early (weeks to a few months)
- Injection-site reactions: redness, swelling, itching, or pain where you inject.
- Mild infections: upper respiratory infections, sore throat, runny nose, headaches.
- Overall feeling of fatigue or malaise can occur as your body adjusts.
- Ongoing or later (months and beyond)
- Infections: the risk of infections can persist while you’re on therapy. You’ll want to watch for signs of infection (fever, persistent cough, shortness of breath, urinary symptoms) and contact your doctor if they occur.
- Fungal infections: mucocutaneous candidiasis (thrush) can occur with IL-17A inhibitors and may appear after longer exposure.
- Gastrointestinal changes: there have been reports of new or worsened inflammatory bowel disease (Crohn’s disease or ulcerative colitis) in some people on IL-17 inhibitors. If you develop persistent diarrhea, stomach pain, or blood in stool, tell your doctor.
- Rare allergic or hypersensitivity reactions: can occur at any time, though they’re uncommon.
- Other rare events: as with many biologics, very rare risks (including effects on blood tests, cardiovascular events, or other infections) have been reported in some patients over long-term use.
- What may help with timing and management
- Before starting: your clinician usually screens for infections (like TB) and reviews your medical history to minimize long-term risks.
- Monitoring: regular follow-up, infection vigilance, and any new GI symptoms should be discussed with your doctor. Blood tests or other tests may be done as part of monitoring in some patients.
- When to contact a clinician urgently: if you develop signs of a serious infection (fever, chills, flu-like symptoms, shortness of breath), signs of severe allergic reaction (hives, swelling of face/lips/tongue, trouble breathing), new or worsening severe abdominal pain with diarrhea, or any unusual or persistent symptoms.
Note: This is general information. Individual side effects and their timing can vary. If you’re taking Cosentyx or plan to start it, discuss your medical history and any concerns with your prescriber, and report any new or worsening symptoms promptly.