Reslizumab (Injection)

Reslizumab is an injection type medication that is used alongside other drugs in the maintenance treatment of patients who have severe asthma. This medicine is used for patients with an eosinophilic phenotype.


Reslizumab is an interleukin inhibitor in injection form. The main use of this medication is as a maintenance treatment for patients who experience severe asthma. It is most commonly used with patients who have an eosinophilic phenotype.

This medication can reduce the number of blood eosinophils in the patient's body. Eosinophils are a type of white blood cell within the body.

This medicine is only given in a controlled, medical environment as part of maintenance treatment, and must be supplied and authorized by a medical professional for treatment to begin.

Conditions Treated

  • Maintenance treatment for severe asthma where patients have an eosinophilic phenotype

Type of Medicine

  • Solution
  • Interleukin inhibitor

Side Effects

As well as the expected and needed conditions that Reslizumab produces, due to the nature of this medication there may be other unwanted or unexpected effects of this treatment method. Not all these results are likely to occur, but should any of the listed become present during treatment with Reslizumab, it's essential to get in contact with your doctor as soon as possible to ensure your health and safety.

If any of the below occur, check with your doctor or a qualified medical professional as soon as possible after they become prevalent:

  • Unusual feelings of tiredness or weakness
  • Tightness in the chest
  • Swelling of the eyelids or around the face, including the eyes and mouth
  • Redness of the skin
  • Puffiness on the face
  • Lightheadedness
  • Hives, itching, or uncomfortable skin rash
  • Fast heartbeat
  • Faintness
  • Dizziness
  • Difficulty with swallowing
  • Cough

Other side effects experienced while taking Reslizumab may not require any medical support or attention and can be expected in many cases of treatment with this medication. The effects of these conditions as a result of taking Reslizumab may reduce or disappear during treatment or if not, should stop soon after stopping this medication.

If you find any of the following side effects worrisome or uncomfortable, you can discuss coping techniques and potential preventative methods with your doctor. Your doctor may be able to support you in deciding on the continuation or alteration of your medication if your side effects continue to affect you negatively, depending on the risks and benefits of Reslizumab.

Inform your doctor if some or any of the below listed continue after concluding treatment, are bothersome, or if you have any queries regarding symptoms you are experiencing:

  • Warmth at the injection site
  • Ulceration
  • Tingling
  • Throat pain
  • Tenderness
  • Swelling
  • Stinging
  • Soreness
  • Scarring
  • Redness
  • Rash
  • Pain
  • Numbness
  • Lumps
  • Itching
  • Inflammation
  • Infection
  • Hives
  • Feeling of pressure
  • Discoloration of the skin
  • Coldness
  • Burning
  • Blistering
  • Bleeding

In addition to the symptoms and side effects listed, other effects may occur in patients that have not been included. Should any other unusual effects or feelings occur, it's important to confirm with your doctor your side effects as soon as possible, especially if they are causing harm or are worrying you.

If you are worried about any side effects you're experiencing, call your doctor for support and advice about side effects. You can report side effects directly to the FDA at 1-800-FDA-1088.


The typical adult dose of Reslizumab for the treatment of severe asthma is a 3 mg/kg IV over 20 to 50 minutes that is repeated every four weeks, to continue to provide maintenance over the condition.

However, this is only the average dose provided, and your doctor may prescribe and decide upon a dosage more suitable to you and your medical needs. This may differ depending on the weight of the patient, as well as age and other factors.

Reslizumab is given every four weeks, and the medication is injected into a vein through an IV. Reslizumab must be administered slowly. Each IV infusion can take up to 50 minutes to complete.

Due to Reslizumab being administered via IV, it is only available to be administered by a trained medical professional, in a clean and suitable environment that helps to prevent infection and other ill effects. Because of this, this medication is strictly controlled by the medical support team involved in the treatment of the patient.


There are no known registered interactions between Reslizumab and any other medications. Also, no specific interactions with food, alcohol or tobacco have been discovered. Despite this, it is vital that your doctor is aware of every medication you are currently taking, or medicines you've recently taken, to ensure that they have access to your full medical history. This list should include all over the counter medications in addition to prescribed drugs, as well as herbal treatments and vitamins.

To make sure that this medicine is safe for you to use, it's critical to inform your doctor if you have recently, or have previously, experienced any of the following conditions:

  • History of parasite infection (e.g. as roundworms or tapeworms)
  • Regular usage of steroid asthma medication

Though Reslizumab does not have any specific issues with interaction, is has been known to cause a serious/life-threatening allergic reaction, including anaphylaxis. Anaphylaxis in particular can be extremely dangerous and needs immediate medical attention.

Tell your doctor as soon as you can if you have any of the following symptoms of an allergic reaction:

  • Dizziness
  • Fainting
  • Itching
  • Lightheadedness
  • Rash
  • Swelling of your hands, face, or mouth
  • Trouble breathing
  • Trouble swallowing


When using Reslizumab within clinical trials, it was found that a small number of people within these tests developed cancer while undergoing treatment with this medication. Currently, it is unknown if Reslizumab itself can cause cancer, but it is suggested that precautions are taken to reduce the risk of cancers such of skin cancer by wearing SPF and protective clothing. Consult with a doctor to discuss your specific risk of illness from Reslizumab.

There are not enough conclusive studies about this medication to know if Reslizumab will harm an unborn baby. Due to this, it is essential to speak to your doctor if you are pregnant, become pregnant during treatment or are planning to become pregnant to decide whether to continue your medication.

Also, it is unknown if Reslizumab passes into breast milk, or if it could cause harm to a nursing baby during treatment with this medication. Your doctor should be informed if you are currently breastfeeding a baby.

Before treatment begins with Reslizumab, your doctor may decide to perform a series of tests to measure the levels of eosinophils (a type of white blood cells) in your blood, to ensure that this medication is the best course of treatment for you.

Reslizumab is not used as a rescue medicine, and should never be considered as a way to prevent immediate issues related to asthma. It will not work soon enough to treat or stop an asthma attack. Only a fast-acting inhalation medication such be used in the case of an asthma attack.

If you have been prescribed a steroid type medication before or alongside Reslizumab, do not stop using this medicine immediately or suddenly, or you may suffer from uncomfortable and unpleasant withdrawal symptoms. Consult with a medical professional about reducing or tapering the steroid dose you are prescribed before stopping using this medication entirely.

Asthma is very often treated with a combination of different drugs and medications, which work together to combat this condition. All medications you are prescribed should be taken as and when directed by your doctor, never take a higher or reduced amount than you are prescribed. Read the guide of your medication or doctor's instructions provided with each prescription medicines for directions about how it should be used. Never alter your doses or medication schedule without your doctor's approval or advice. If it seems your asthma medications are not working, or are less effective than previous medications, speak to you doctor about alternatives.


The chemical and physical in-use stability of Reslizumab has been demonstrated at 2 °C-8 °C or at 25 °C in sodium chloride 9 mg/mL (0.9%) solution used for infusion when protected from light for 16 hours.

When ready, Reslizumab should be injected into the patient immediately. If not used immediately, storage should not be for longer than 16 hours at a refrigerated temperature of 2 °C-8 °C, unless dilution has already taken place within a controlled and validated aseptic condition.

Never freeze this medication, and ensure the vial that Reslizumab comes in is kept within the outer carton to offer additional protection from light.


Reslizumab injection is used for patients with severe asthmatic symptoms and is often used alongside other medications for a comprehensive treatment plan to combat the effects of acute asthma in patients who have an eosinophilic phenotype.

This medication can reduce eosinophils in the blood, a type of white blood cell. Reslizumab is administered as in IV and only prescribed and used in a clinical medical environment to prevent any issues with infection or error.


Last Reviewed:
February 01, 2018
Last Updated:
January 27, 2018
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