This article is more than 5 years old. Information may no longer be current.
Relapse rates higher with antithyroid drugs in Graves’ disease
Relapse rates appear to be higher with antithyroid drugs vs. other treatment options for Graves’ disease, and there is a lack of high-quality evidence comparing these therapies, a recent meta-analysis suggests.
To determine these rates and to understand adverse events associated with antithyroid drugs, Vishnu Sundaresh, MD, clinical fellow of endocrinology and metabolism at Louisiana State University Health Sciences Center Hospital, and colleagues analyzed data from eight studies including 1,402 patients from five continents. The mean follow-up duration was 57 months for patients using antithyroid drugs, 64 months for those who underwent radioactive iodine (RAI) therapy, and 59 months for those who underwent thyroidectomy.
Vishnu Sundaresh
“We conducted a systemic review and network analysis of the three therapeutic options for the treatment of Graves’ hyperthyroidism in order to inform the patient-physician discussion regarding choice of therapy and to determine the quality of evidence available in the literature supporting the efficacy of these therapies,” researchers wrote.
Based on the network meta-analysis, data indicate greater relapse rates with antithyroid drugs compared with RAI (OR=6.25; 95% CI, 2.40-16.67) and with antithyroid drugs compared with thyroidectomy (OR=9.09; 95% CI, 4.65-19.23). The researchers found no significant difference in relapse rates among patients who underwent RAI vs. those who underwent thyroidectomy.
An examination of 31 cohort studies showed that 13% of patients experienced adverse events related to antithyroid drugs. The adverse events associated with methimazole (Tapazole, King Pharmaceuticals) largely involved dermatologic complications, while adverse events associated with propylthiouracil more often included hepatic effects, according to data.
However, the studies were considered to be low-quality and at moderate to high risk for bias, researchers wrote.
These findings could spark discussion between clinicians and patients regarding a choice of therapy, researchers wrote, but more high-quality studies and randomized, controlled trials are warranted.
Disclosure: The researchers report no relevant financial disclosures.
Perspective
Back to Top
Comparative effectiveness research is research evaluating and comparing health outcomes and the clinical effectiveness, risks and benefits of two or more medical treatments or services. In this study, the authors compared relapse rates and adverse events among three standard treatments for hyperthyroidism due to Graves’ disease: antithyroid drug therapy, radioiodine therapy and surgery. The studies that they analyzed included one randomized controlled trial and the rest of the studies were retrospective cohort studies. The authors concluded that antithyroid drug therapy is associated with a higher rate of relapse compared with radioiodine or surgery, and that antithyroid drug therapy is also associated with more adverse events. These facts are well-known to clinicians, and form the backbone of any discussion that is had with a patient with hyperthyroidism due to Graves’ disease, in order to help him/her make an informed decision about the “best treatment” for them.
The American Thyroid Association guidelines for the management of hyperthyroidism provides a framework for helping decision-making by providing factors that may favor a particular modality by the treating physician or factors that may impact a patients’ preference. For example, even though antithyroid drugs have a higher rate of relapse and adverse events, they are preferred by many patients because they are not destructive, do not expose the body to radiation, and do not have an increased risk of worsening or initiating thyroid eye disease. Furthermore, they offer the hope of potential remission without the need for any additional treatment.
The paper concludes that the low quality of evidence underlines the need for additional studies. However, it is unclear whether additional studies will provide any additional meaningful data about which treatment is “better,” since the treatments are so different. In the future, other treatments, such as new immunosuppressive agents and TSH receptor antagonists may also play a role in the treatment of Graves’ disease, and will also need to be subjected to comparative effectiveness analysis. Importantly, the authors did not mention cost effectiveness, just treatment outcomes. Studies that have analyzed cost effectiveness have generally concluded that radioiodine is the most cost-effective therapy over the long term.