Medical management of hyperprolactinemia: a lower dose of bromocriptine may be effective.

This prospective study includes 31 women with a prolactin (PRL) level greater than 20 ng/ml (upper limits of normal in our laboratory) on at least three different occasions and chemically euthyroid. Each woman received bromocriptine mesylate (BRC) 1.25 mg (1/2 tablet)/day for 2 weeks, at which time a repeat PRL level was obtained. If needed, the dose was increased in a stepwise fashion until the PRL level was in the normal range. Results show that 12 of 15 patients with an initial PRL greater than 20 but less than 50 ng/ml required 2.5 mg or less of BRC daily. Of 9 patients with a PRL greater than 50 but less than 100 ng/ml, 5 required 2.5 mg daily with the remaining 4 needing 5.0 mg. Five of 7 patients with a PRL greater than 100 ng/ml required 5.0 mg or more, while one responded to 1.25 mg. These findings confirm that a lower than manufacturer-recommended dose of BRC is usually effective in normalizing PRL levels, especially when the initial PRL is less than 100 ng/ml.