Kesimpta is a medication used primarily to treat relapsing forms of multiple sclerosis (MS). It works by targeting specific immune cells to reduce inflammation and slow disease progression. Like many medications, Kesimpta can cause side effects, which range from mild to potentially serious. Understanding these side effects can help patients and caregivers manage them effectively and know when to seek medical attention.
The most common side effects of Kesimpta are related to the injection process itself since it is administered as a subcutaneous injection (under the skin). Many people experience **injection site reactions**, which can include redness, swelling, pain, itching, or a small lump at the spot where the injection was given. These reactions are usually mild and tend to improve with continued use as the body adjusts.
Beyond injection site issues, some people report **upper respiratory infections**, such as the common cold, which may manifest as a sore throat, runny nose, or cough. These infections are generally mild but can be more frequent in people taking Kesimpta because the medication affects the immune system.
Other common side effects include **headache** and **muscle pain or weakness**. These symptoms can vary in intensity but often improve over time or with supportive care such as rest and hydration.
Because Kesimpta modifies the immune system, it can increase the risk of infections. Patients should be alert for signs of infection such as fever, chills, persistent cough, or unusual tiredness. If these symptoms occur, it is important to contact a healthcare provider promptly.
Less commonly, Kesimpta may cause **allergic reactions**. These can range from mild skin rashes or itching to more severe reactions like swelling of the face, lips, tongue, or throat, which can cause difficulty breathing or swallowing. Severe allergic reactions require immediate medical attention.
Some patients might experience **neurological symptoms** such as dizziness, unsteadiness, or unusual sensations like numbness or tingling. While these can sometimes be related to MS itself, if they worsen or are new, they should be evaluated by a doctor.
There is also a potential for **eye problems**, including pain, redness, or vision changes, which should be reported to a healthcare professional as soon as possible.
Fatigue or a general feeling of weakness is another side effect that some people experience. This can be part of the disease process or a reaction to the medication.
Rare but serious side effects may include liver problems, which might present as yellowing of the skin or eyes (jaundice), dark urine, or persistent stomach pain. Blood tests can monitor liver function during treatment.
Because Kesimpta affects immune cells, it can also impact blood cell counts, potentially leading to anemia (low red blood cells), leukopenia (low white blood cells), or thrombocytopenia (low platelets). Symptoms of these conditions might include unusual bruising or bleeding, persistent infections, or extreme fatigue.
Patients are advised to have regular follow-ups with their healthcare providers to monitor for these side effects and to have blood tests as recommended.
In summary, the side effects of Kesimpta primarily involve injection site reactions, increased risk of infections, flu-like symptoms such as headache and muscle pain, and potential allergic reactions. More serious but less common effects include liver issues, blood cell abnormalities, and neurological or eye problems. Awareness and prompt communication with healthcare providers can help manage these side effects effectively.
