Hydroxyurea Underused in Youth With Sickle
Cell Anemia

Marcia Frellick

March 27, 2023

Even after endorsement in updated guidelines, hydroxyurea is substantially underused in youth with sickle cell anemia (SCA), new research indicates.

SCA can lead to pain crises, stroke, and early death. Hydroxyurea, an oral disease-modifying medication, can reduce the complications.

In 2014, the National Heart, Lung, and Blood Institute published revised guidelines that hydroxyurea should be offered as the primary therapy to all patients who were at least 9 months old and living with SCA, regardless of disease severity.

Low uptake even after guideline revision

Yet, a research team led by Sarah L. Reeves, PhD, MPH, with the Child Health Evaluation and Research Center at University of Michigan, Ann Arbor, found in their study of use in two sample states — Michigan and New York — that hydroxyurea use was low in children and adolescents enrolled in Medicaid and increased only slightly in Michigan and not at all in New York after the guideline revision.

After the guidelines were updated, the researchers observed that, on average, children and adolescents were getting the medication less than a third of the days in a year (32% maximum in the year with the highest uptake). The data were gathered from a study population that included 4,302 youths aged 1-17 years with SCA.

Findings were published online in JAMA Network Open.

"A national issue"

Russell Ware, MD, PhD, chair of hematology translational research at Cincinnati Children's Hospital, who was not part of the research, says that though data were gathered from Michigan and New York, "this is a national issue."

Dr. Ware says the main problem is the way the health system describes the importance of hydroxyurea.

"There needs to be a realization that hydroxyurea is the standard of care for children with sickle cell anemia. It's not just something they should take when they're sick," Dr. Ware said.

He added, "If you have diabetes, should you only take insulin if you're really sick and hospitalized with a diabetic coma? Of course not."

He said often providers aren't giving a clear and consistent message to families.

"They're not all sure they want to recommend it. They might offer it," Dr. Ware said, which jeopardizes uptake. "Providers need to be more committed to it. They need to know how to dose it."

Bad rap from past indications

Dr. Ware says hydroxyurea also gets a bad rap from use decades ago as a chemotherapeutic agent for cancer and then as an anti-HIV medication.

Now it's used in a completely different way with SCA, but the fear of the association lingers.

"This label as a chemotherapeutic agent has really dogged hydroxyurea," he said. "It's a completely different mechanism. It's a different dose. It's a different purpose."

The message to families should be more direct, he says: "Your child has sickle cell anemia and needs to be on disease-modifying therapy because this is a life-threatening disease."

The underuse of this drug is particularly ironic, he says, as each capsule, taken daily, "costs about fifty cents."

Medicaid support critical

Authors conclude that multifaceted interventions may be necessary to increase the number of filled prescriptions and use. They also point out that the interventions rely on states' Medicaid support regarding hydroxyurea use. From 70% to 90% of young people with SCA are covered by Medicaid at some point, the researchers write.

"Variation may exist across states, as well as within states, in the coverage of hydroxyurea, outpatient visits, and associated lab monitoring," they note.

The authors point to interventions in clinical trials that have had some success in hydroxyurea use.

Creary et al., for example, found that electronic directly observed therapy was associated with high adherence. That involved sending daily texts to patients to take hydroxyurea and patients recording and sending daily videos that show they took the medication.

The authors add that incorporating clinical pharmacists into the care team to provide education and support for families has been shown to be associated with successful outcomes for other chronic conditions — this approach may be particularly well suited to hydroxyurea given that this medication requires significant dosage monitoring.

Dr. Ware, however, says that solutions should focus on the health system more clearly communicating that hydroxyurea is the standard of care for all kids with SCA.

"We need to dispel these myths and these labels that are unfairly attributed to it. Then we'd probably do a lot better," he said.

He added that children with SCA, "are a marginalized, neglected population of patients historically," and addressing social determinants of health is also important in getting better uptake.

"Our pharmacy, for example, ships the drug to the families if they're just getting a refill rather than making them drive all the way in," Dr. Ware says.

Dr. Ware said given the interruption in doctor/patient relationships in the pandemic, the poor uptake of hydroxyurea could be even worse now.

The work was funded by the Agency for Healthcare Research and Quality and National Heart, Lung, and Blood Institute. Coauthor Dr. Green was the principal investigator of an NIH-funded trial of hydroxyurea in Uganda with a study drug provided by Siklos. No other author disclosures were reported. In addition to receiving research funding from the National Institutes of Health, Dr. Ware receives research donations from Bristol Myers Squibb, Addmedica, and Hemex Health. He is a medical adviser for Nova Laboratories and Octapharma, and serves on Data Safety Monitoring Boards for Novartis and Editas.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.


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