Cardiovascular outcomes similar for generic and brand-name drugs for hypothyroidism

Cardiovascular event rates were similar for generic and brand-name levothyroxine drug used to treat hypothyroidism, with lower pharmacy costs for the generic drug, finds a study.

The study to be published in the journal 'Mayo Clinic Proceedings' suggests that generic or brand-name levothyroxine may be used to treat hypothyroidism due to benign thyroid disorders. The average 30-day cost of the generic drug was about half the cost of brand-name medication for patients and insurers.

"More than 90 per cent of thyroid prescriptions are for levothyroxine, and there has been disagreement as to whether generic levothyroxine and branded thyroxine preparations are equivalent," said Robert Smallridge, the study's principal investigator.

"These findings suggest that generic and brand levothyroxine therapy are similar as related to cardiovascular events risk," said Dr Smallridge.

Dr Smallridge said the findings require confirmation with longer-term follow-up and study of subsets of patients, such as those with a history of thyroid cancer, who frequently receive higher doses of levothyroxine.

Hypothyroidism, or underactivity of the thyroid gland, affects the function of many organs in the body, elevating blood cholesterol levels and increasing the risk of heart attacks, heart failure, and stroke. Levothyroxine is used to reduce elevated cholesterol and reverse symptoms of hypothyroidism.

The analysis was unusual in that it used information from an administrative claims database provided by OptumLabs Data Warehouse. This data warehouse contains deidentified administrative claims data, as well as deidentified electronic health record data from a nationwide network of provider groups.

The study reviewed records for 87,902 patients followed for a mean period of one year, focusing on hospitalisation for heart attacks, congestive heart failure, atrial fibrillation or strokes. The analysis found no difference in event rates for the four types of cardiovascular events.