From the Guidelines
Hydroxyurea should be paused during active infections due to its immunosuppressive effects, which can worsen the body's ability to fight off the illness. This is because hydroxyurea suppresses bone marrow function, reducing the production of white blood cells that are crucial for combating infections 1. When an infection is already present, continuing hydroxyurea could further lower the white blood cell count, potentially leading to more severe consequences. Some key points to consider when managing hydroxyurea during infections include:
- Temporarily stopping hydroxyurea at the first sign of infection, especially if fever develops
- Resuming hydroxyurea only after the infection has resolved and the white blood cell count has normalized
- The duration of discontinuation depending on the severity of the infection, as determined by a healthcare provider
- Balancing the risks of discontinuation against the underlying condition being treated, such as sickle cell disease or certain blood disorders, as noted in guidelines like those from the American Society of Hematology 1. It's essential to consult with a doctor before stopping or restarting hydroxyurea, as the decision should be made on a case-by-case basis, considering the individual's specific health status and the potential benefits and harms of continuing or pausing the medication.
From the FDA Drug Label
Advise patients to inform their healthcare provider if they have received or are planning to receive vaccinations while taking hydroxyurea capsules as this may result in a severe infection [see Warnings and Precautions (5.6)]. The reason you can’t take hydroxyurea during infection is that myelosuppression can occur, and infection can be a sign of this condition. Additionally, patients taking hydroxyurea should report signs and symptoms of infection immediately. It is also advised that patients inform their healthcare provider if they have received or are planning to receive vaccinations while taking hydroxyurea capsules, as this may result in a severe infection 2.
- Key points:
- Risk of myelosuppression
- Risk of severe infection with vaccinations
- Patients should report signs and symptoms of infection immediately
From the Research
Hydroxyurea and Infections
There is no direct evidence in the provided studies that suggests hydroxyurea should not be taken during an infection. However, some points to consider:
- Hydroxyurea is a myelosuppressive agent, which means it can suppress the bone marrow's ability to produce blood cells, including white blood cells that fight infections 3.
- The use of hydroxyurea can lead to side effects such as neutropenia, which is a low count of neutrophils, a type of white blood cell that helps fight infections 3, 4.
- In the study 4, one of the comparisons found more occurrences of acute chest syndrome and infections in the hydroxyurea and phlebotomy group compared to the transfusion and chelation group.
Considerations for Hydroxyurea Use
Some key points to consider when using hydroxyurea:
- Hydroxyurea is effective in decreasing the frequency of pain episodes and other acute complications in adults and children with sickle cell anemia of HbSS or HbSβºthal genotypes 4.
- Hydroxyurea can prevent life-threatening neurological events in those with sickle cell anemia at risk of primary stroke by maintaining transcranial doppler velocities 4.
- The long-term benefits and risks of hydroxyurea, including its effects on fertility and reproduction, are still not well understood and require further study 4.