Delayed Visual Loss Following Pergolide Treatment of a Prolactinoma

A patient who had achieved marked improvement in vision and shrinkage of a prolactinoma following treatment with pergolide (0.1 mg/day) suffered a marked worsening of vision 7 months after continued treatment at the same dose. Brain magnetic resonance imaging (MRI) at the time of visual loss showed further shrinkage of the tumor and prolapse of the chiasm into the pituitary fossa. The dose of pergolide was cut in half (0.05 mg/day); 12 months...