Following warnings in Britain and the United States about the cardiac risks of dopamine agonists Parkinson's disease management, the British Society of Endocrinology recommends continuing the agents for the treatment of pituitary disorders, but with caution.
“Dopamine agonists remain the first-line agents for the management of hyperprolactinaemia and a useful adjunct in the management of acromegaly,” noted a statement released Oct. 9 by the society. However, the lowest effective dose, or even withdrawal of dopamine agonists, should be considered when appropriate.
In response to studies showing an increased risk of mitral, tricuspid, and aortic valve regurgitation associated with the dopamine agonist pergolide, the Food and Drug Administration announced the voluntary withdrawal of pergolide products by manufacturers in March. The United Kingdom's regulatory agency imposed restrictions on the use of another dopamine agonist, cabergoline, in treating Parkinson's disease, but did not make reference to pituitary disease, noted the Society of Endocrinology statement.
While endocrine disorders require considerably lower doses of cabergoline compared with Parkinson's disease, endocrine patients are treated for longer durations. “As the published data indicate that the risk of valve disease relates to the cumulative dose, there is need for vigilance in patients with pituitary disease,” it said. The society recommends screening echocardiograms for patients treated for longer durations, or with high doses of cabergoline. “Bromocriptine has not been implicated as a cause of cardiac fibrosis and remains an effective alternative to cabergoline,” it advised.
The society stated its support for a recommendation in the British National Formulary from the Committee on Safety of Medicines. “Before starting treatment with these ergot derivatives it may be appropriate to measure the erythrocyte sedimentation rate and serum creatinine and to obtain a chest x-ray. Patients should be monitored for dyspnoea, persistent cough, chest pain, cardiac failure and abdominal pain or tenderness. If long-term treatment is expected, then lung-function tests may also be helpful.”
To date, there are no reports of cardiac valve fibrosis tied to dopamine agonist treatment of endocrine disorders.