From the Guidelines

Hydroxyurea is not directly associated with an increased risk of acute infection.

The provided evidence does not establish a direct link between hydroxyurea and acute infection, focusing instead on its use in sickle cell disease (SCD) for primary stroke prevention and management of pulmonary hypertension 1.
Hydroxyurea has been shown to decrease the incidence of acute chest syndrome (ACS) and vaso-occlusive crises (VOC) in patients with SCD, which could indirectly suggest a reduction in the risk of acute infections by reducing the frequency of these crises 1.
However, the evidence primarily highlights the benefits of hydroxyurea in reducing stroke risk, managing pulmonary hypertension, and decreasing mortality in SCD patients, without directly addressing its relationship with acute infections 1.
It is essential to consider that while hydroxyurea may not increase the risk of acute infection, its immunosuppressive effects could potentially influence infection risk, although this is not explicitly discussed in the provided evidence.
The decision to use hydroxyurea should be based on its established benefits in SCD management, with careful monitoring for potential side effects, including any impact on infection risk, in real-life clinical practice.

From the Research

The relationship between hydroxyurea and acute infection is complex and has been studied in various contexts, including sickle cell disease and HIV infection 2, 3, 4.
In the context of sickle cell disease, hydroxyurea has been shown to decrease the frequency of pain episodes and other acute complications, including acute chest syndrome and infections 2.
However, one study found that switching from hydroxyurea to partial exchange transfusions may increase the risk of acute chest syndrome and infections 3.
In the context of HIV infection, hydroxyurea has been shown to inhibit viral DNA synthesis and synergistically interact with nucleoside reverse transcriptase inhibitors, but its use is also associated with concerns about toxicity and adverse effects 4.
The pharmacokinetics and pharmacodynamics of hydroxyurea have been studied, and the drug has been found to have a high volume of distribution and elimination through both renal and nonrenal mechanisms 5.
Overall, the evidence suggests that hydroxyurea may have both beneficial and adverse effects on acute infection, depending on the context and population being studied 2, 3, 4, 5, 6.

Hydroxyurea decreases the frequency of pain episodes and other acute complications in sickle cell disease 2.
Switching from hydroxyurea to partial exchange transfusions may increase the risk of acute chest syndrome and infections 3.
Hydroxyurea inhibits viral DNA synthesis and synergistically interacts with nucleoside reverse transcriptase inhibitors in HIV infection 4.
Hydroxyurea has a high volume of distribution and elimination through both renal and nonrenal mechanisms 5.
The drug is associated with dose-related bone marrow suppression and toxicity, but its ease of administration and low cost ensure its continued use in therapy 6.