Like any other drug, the asthma medication benralizumab (Fasenra) can cause side effects in some people. Most of these problems are mild. Some side effects may go away once your body gets used to the drug. Others can be bothersome, or even serious.
When you know what to look out for, you can take steps to manage any side effects you may have. And you'll know when it's time to talk to your doctor.
How to Manage Common Side Effects of Benralizumab (Fasenra)
The most common side effects of benralizumab are headaches and a sore throat.
Headache. A review of several clinical studies on the safety and effectiveness of benralizumab found that just over 8% of people in the studies said they had a headache while they took the drug. By comparison, just over 5% of people who got a fake treatment, called a placebo, got a headache.
The headaches reported with benralizumab were usually mild and didn't need any treatment. If this happens to you, ask your doctor if you can take an over-the-counter pain reliever like aspirin, ibuprofen, or acetaminophen to make you more comfortable until the headache ends.
If your headache doesn’t go away, talk to your doctor. You might need prescription medicine or other treatments.
Sore throat. A small number of people in studies said they had a sore throat after they took benralizumab. To relieve this side effect:
- Drink warm liquids, like tea, to soothe your throat.
- Suck on a lozenge or hard candy.
- Gargle with a mixture of ½ teaspoon salt and 4-8 ounces of warm water.
- Use a humidifier or sit next to a hot running shower and breathe in the steam.
If your sore throat doesn't go away in a few days, ask your doctor for advice.
How to Manage Other Mild Side Effects of Benralizumab (Fasenra)
Benralizumab may cause some other mild side effects. They include:
Fever. In four studies, 4% of people who took benralizumab had a fever, compared to just under 2% of people who took a placebo. Tell your doctor if you have this side effect.
Your doctor might recommend that you take a fever-lowering medicine like aspirin, ibuprofen, or acetaminophen. Rest until you feel better. Drink plenty of fluids so you don't get dehydrated.
Injection site reactions. You take benralizumab as a shot just under your skin. About 2% of people in studies who took this medicine had a reaction where the shot went into their skin. Symptoms of injection site reactions include:
- Bumps on the skin
- Itching
- Pain
- Swelling
These side effects happen because your immune system reacts to the needle, the medicine, or both. The reaction might start right after the injection or hours later. Most of the time, it's not serious and will go away on its own.
If you inject yourself with benralizumab, carefully follow your doctor’s instructions. Before you give yourself the shot, let the medication sit at room temperature for 30 minutes to warm up. Never try to warm it in the sun or in a microwave. Before your shot, look at the liquid in the autoinjector. Don’t use it if it’s cloudy, you see particles floating in it, or if the injection pen is broken.
Keep track of where on your body you give yourself the shot each month, and alternate locations to prevent skin problems. Don’t inject benralizumab into any moles or scars, or areas of skin that are red, bruised, or sore. Never try to reuse an autoinjection pen.
An ice pack can relieve any pain and swelling. Ask your doctor if you need over-the-counter or prescription medicine to manage your symptoms. Get medical help right away if you have signs of a more severe reaction, such as a rash, hives (red bumps that are sometimes itchy), or trouble breathing.
What to Do if You Have Serious Side Effects With Benralizumab (Fasenra)
It's rare, but benralizumab could cause a serious or even life-threatening allergic reaction called anaphylaxis. Symptoms of anaphylaxis include:
- Confusion
- Dizziness or fainting
- Hives
- Nausea or vomiting
- Pounding or fast heartbeat
- Swelling of your lips, tongue, throat, or other areas of skin
- Trouble breathing or wheezing (a whistling sound when you breathe)
These symptoms usually start within a few hours after the injection, but they may not appear for days. If you have these symptoms, call your doctor right away or go to the emergency room. You’ll need to stop taking benralizumab if you’re allergic to it.
