Oxbryta for Sickle Cell Disease

Reviewed by: HU Medical Review Board | Last reviewed: February 2023

Oxbryta was approved by the U.S. Food and Drug Administration (FDA) in 2021 to treat sickle cell disease (SCD) in people 4 years of age and older. It reduces anemia by preventing red blood cells from sickling.1

Oxbryta can be taken alone or with hydroxyurea. Unfortunately, it is much more expensive than hydroxyurea right now.

What are the ingredients in Oxbryta?

The active ingredient in Oxbryta is voxelotor.1

How does Oxbryta work?

Oxbryta increases the ability of sickle hemoglobin to bind to oxygen. When sickle hemoglobin is not bound to oxygen, it clumps together inside red blood cells. This causes red blood cells to become sickle-shaped and rigid. By helping hemoglobin bind to oxygen, Oxbryta reduces hemoglobin clumping inside red blood cells. This helps prevent red blood cells from sickling and bursting prematurely because of their rigidity (hemolysis).1

By reducing hemolysis, Oxbryta increases hemoglobin levels and improves anemia. It may also treat jaundice, which is a symptom of anemia. Oxbryta may also help reduce the risk of acute pain crises caused by blocked blood flow. However, more studies are needed.2,3

What are the possible side effects?

The most common side effects of Oxbryta include:4

  • Headache
  • Diarrhea
  • Abdominal pain
  • Nausea
  • Rash
  • Fever

Allergic reactions to Oxbryta are rare but can occur. Get emergency help if you notice signs of an allergic reaction, such as:4

  • Shortness of breath
  • Hives
  • Swelling of the face

These are not all the possible side effects of Oxbryta. Talk to your doctor about what to expect when taking Oxbryta. You also should call your doctor if you have any changes that concern you when taking Oxbryta.

Additional things to know

Take Oxbryta exactly as prescribed by your doctor. It is important to remember to take it every day for it to work best.4

Before taking Oxbryta, tell your doctor if you have any other medical conditions, especially liver disease.4

Do not take Oxbryta if you have had an allergic reaction to it before. Before taking Oxbryta, tell your doctor about any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs. Your doctor may adjust your dosage of Oxbryta depending on these factors.

There is not enough information about Oxbryta to know whether it is safe to use when pregnant or breastfeeding. Before taking this medicine, talk to your doctor if you are pregnant or breastfeeding, or plan to become pregnant.4

Oxbryta can be taken alone or with hydroxyurea. Unfortunately, Oxbryta is much more expensive than hydroxyurea. It costs about $100,000 a year and must be taken for a long time. The price must be lowered for most people with SCD to experience cost-effective benefits. Experts hope health insurance companies will pay for it, but insurers may require that people try hydroxyurea alone first.5

For more information, read the full prescribing information of Oxbryta.

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