Dr. Ahmed According to the FDA prescribing information, weight gain is not a side effect of Fasenra. Because people using it may have noticed some change in their body weight, they are usually concerned about putting on weight.
Here, I post a patient’s concerns and his doctor’s discussion when he was prescribed Fasenra (Benralizumab).
| Patient: “I wanted to share a bit about my experience with asthma over the past couple of years. I’ve been using the inhaler Seretide and the tablet Singulair to manage my symptoms, but despite that, I’ve been experiencing frequent asthma exacerbations. My doctor has prescribed an oral course of prednisolone for me a few times, but it’s not a long-term solution, and I’ve been looking for something that can help me manage my asthma more effectively in the long run. That’s why my doctor recently prescribed an injection of Fasenra for me, starting with 30 mg every month for three doses and then every two months. While I’m hopeful that Fasenra will help me manage my asthma more effectively, I am a bit worried about potential side effects, particularly weight gain. Over the past couple of years, I have already gained some weight, and I’m concerned that Fasenra could make that even worse. However, I’m trying to stay positive and focus on the potential benefits of the medication. I hope it will help me get off the corticosteroids. Of course, I’ll be working closely with my doctor to monitor any side effects that I experience and manage them as effectively as possible. I just wanted to share a bit about my journey with asthma and my hopes for the future. Thanks for listening.” |
| Doctor: “I’m sorry to hear that you have been struggling with frequent asthma exacerbations despite using inhalers and tablets for the past two years. It must have been frustrating to have to rely on oral courses of prednisolone to manage your symptoms. And now, with the prescription of Fasenra, you are worried about gaining even more weight. It’s understandable to feel anxious about the potential for weight gain with Fasenra. After all, weight gain can be a difficult side effect to manage and can add to the challenges of living with asthma. You may be concerned about your appearance, your health, and the impact that the weight gain could have on your ability to manage your asthma in the long term. It’s important to remember, however, that Fasenra is a powerful medication that can help to reduce the frequency and severity of asthma exacerbations in people with severe eosinophilic asthma. While weight gain can be a potential side effect of Fasenra, it’s not a guaranteed outcome. Your doctor will monitor your progress closely and work with you to manage any side effects that you experience, including weight gain. It’s also worth noting that weight gain is not always a negative outcome. In some cases, weight gain may be a sign that your body is responding positively to the treatment and that your asthma is becoming better controlled. Ultimately, the most important thing is to work closely with your doctor and follow your treatment plan as closely as possible to manage your asthma and improve your quality of life.” |
One important point I noticed here is that weight gain can also be an indicator of good health. When your symptoms get better, you start eating, your quality of life improves, and you gain weight.
Asthma Medications and weight gain:
Most asthma medicines, especially those used as inhaler devices do not cause weight gain. Oral corticosteroids are notorious for causing significant weight gain.
In addition, shortness of breath may limit a person’s mobility resulting in weight gain.
Here is a table of some asthma medications that may cause weight gain:
Medication | Mechanism of action | Weight gain |
| Prednisone | Systemic corticosteroid | Common side effect |
| Fluticasone/Salmeterol (Advair) | Inhaled corticosteroid and long-acting beta-agonist | Less common side effect |
| Budesonide/Formoterol (Symbicort) | Inhaled corticosteroid and long-acting beta-agonist | Less common side effect |
| Mometasone/Formoterol (Dulera) | Inhaled corticosteroid and long-acting beta-agonist | Less common side effect |
It’s worth noting that weight gain is not a guaranteed side effect of these medications, and individual experiences may vary.
Corticosteroids are well known for their weight-gaining properties. What about Biologicals?
Here’s a table of biological medicines used to treat asthma and their potential for causing weight gain:
| Biological medicine | Mechanism of action | Potential for weight gain |
| Omalizumab (Xolair) | Binds to IgE to reduce allergic response | Less common side effect |
| Mepolizumab (Nucala) | Targets IL-5 to reduce eosinophil activity | Not a common side effect |
| Reslizumab (Cinqair) | Targets IL-5 to reduce eosinophil activity | Not a common side effect |
| Benralizumab (Fasenra) | Targets IL-5 receptor to reduce eosinophil activity | Not a common side effect |
| Dupilumab (Dupixent) | Targets IL-4 and IL-13 to reduce allergic response | Less common side effect |
Xolair and Dupixent have been reported to be associated with some weight gain, the rest of the novel biologicals are not associated with weight gain.
What is Fasenra [Ref]?
Fasenra is the brand name of Benralizumab, a prescription drug used to treat severe eosinophilic asthma in adults and children ages 12 years and older. It reduces eosinophilic activity by inhibiting the IL-5-dependent pathway.
Fasenra is administered as a subcutaneous injection once every four weeks for the first three doses, and then once every eight weeks thereafter.
It is helpful in patients with severe eosinophilic asthma by reducing exacerbations and improving lung function.
Fasenra reduces the rate of asthma exacerbations by 51% compared to placebo in patients with blood eosinophil counts of 300 cells/μL or higher [Ref].
In addition, Fasenra has been shown to improve asthma control and quality of life in patients with severe eosinophilic asthma.
What are the side effects of Fasenra?
Some of the common and uncommon side effects of Fasenra are tabulated below:
System | Common side effects | Less common side effects |
| Skin | Injection site reactions (such as pain, redness, swelling, or itching) | Hypersensitivity reactions (such as anaphylaxis, hives, or swelling of the face, lips, tongue, or throat) |
| Nervous system | Headache, fatigue | – |
| Respiratory system | Sore throat, runny or stuffy nose | – |
| Musculoskeletal system | Back pain, muscle pain | – |
| Immune system | – | Parasitic infections (such as roundworm or tapeworm infections) |
| Viral infections | Influenza | Herpes virus infections (such as cold sores or genital herpes) |
Some of the side effects mentioned in the FDA-prescribing information are mentioned above. Weight gain as a side effect of Fasenra has not been mentioned anywhere in the FDA labeling.
Because some side effects are noted once the drug is on the market and people start using it, weight gain may be one of the side effects.
To see how many people have noticed weight gain using Fasenra, here is a POLL comprising 8 questions. It takes 8 to 10 seconds to answer these questions.
Kindly answer the questions to know better if Fasenra is associated with weight gain or not.
- Question of
Have you been using Fasenra to treat your severe eosinophilic asthma?
- Yes
- No
- Question of
Have you experienced any changes in weight since starting Fasenra?
- Yes
- No
- Question of
If you have experienced a change in weight, has it been a gain or loss?
- Gained
- Lost
- No effect
- Question of
How much weight change have you noticed using Fasenra?
- Less than 5 lbs
- More than 5 lbs
- Question of
If you have experienced a change in weight, do you feel that it is related to the use of Fasenra?
- Yes
- No
- Question of
How would you rate your overall satisfaction with the use of Fasenra to treat your asthma?
- 😍😍
- 🙂🙂
- 😥😥
- Question of
Would you recommend Fasenra to others with severe eosinophilic asthma?
- Yes
- No
- Question of
Do you feel that Fasenra has effectively improved your asthma symptoms?
- Yes
- No
