New therapeutic avenues
The first-line treatment for primary Raynaud’s is behavioral interventions, such as maintaining body and extremity warmth and avoiding certain vasoconstricting drugs, said Kimberly Lakin, MD, a rheumatologist at the Hospital for Special Surgery in New York, who not involved in the research. These drugs could include over-the-counter decongestants and certain medications for attention-deficit/hyperactivity disorder.
Hospital for Special Surgery
Dr. Kimberly Lakin
If these behavioral interventions are not enough, clinicians most commonly prescribe calcium channel blockers. These medications are vasodilators but can be a concern for people with normal or already low blood pressure, Dr. Lakin said. They can also cause symptoms such as headache, leg swelling, constipation, and other gastrointestinal symptoms.
Other medications, such as fluoxetine, may also be considered as a later-line therapy, “but the effectiveness is fairly limited in Raynaud’s,” she said. “Certainly, other medication options that would be helpful and driven by the mechanisms of Raynaud’s would add to our ability to help patients.”
As it turns out, one of the genes identified in the study, ADRA2A, “is actually one of the most commonly targeted genes by drugs,” said Dr. Pietzner. Because the findings suggest that ADRA2A is overexpressed in Raynaud, a selective inhibitor like the antidepressant mirtazapine could be a promising candidate to repurpose for treating Raynaud’s, he said.
Limitations to electronic medical record analyses
Both Dr. Hummers and Dr. Lakin noted that research using diagnostic codes from medical records to identify cases has some limitations. The study may have included patients misdiagnosed with Raynaud’s when perhaps they had another condition. Patients with milder Raynaud’s who have not sought medical attention for the condition would not be represented in the study, Dr. Lakin said.
The UK Biobank includes individuals of mostly European descent, so an analysis confirming these findings in a more diverse population would be helpful, she said.
However, both Dr. Lakin and Dr. Hummers agreed that the study contributes to the understanding of the mechanisms behind Raynaud’s. Although the two identified genes were tied to primary Raynaud’s, the study’s findings could potentially apply to secondary Raynaud’s as well, Dr. Hummers said.
“Anything we learn about primary Raynaud’s may have implication for Raynaud’s more broadly,” she noted.
Dr. Hummers and Dr. Lakin disclosed no relevant financial relationships. Dr. Pietzner has received partnership funding for the MRC Clinical Pharmacology Training Scheme (cofunded by MRC and Roche, UCB, Eli Lilly, and Novartis) and a PhD studentship jointly funded by the UK Engineering and Physical Sciences Research Council and AstraZeneca. Dr. Pietzner also has unrestricted educational grant support for the UK Pharmacogenetics and Stratified Medicine Network from Bristol-Myers Squibb.
A version of this article appeared on Medscape.com.