From the FDA Drug Label
As with other drugs that antagonize dopamine D2 receptors, RISPERIDONE elevates prolactin levels and the elevation persists during chronic administration. RISPERIDONE is associated with higher levels of prolactin elevation than other antipsychotic agents. Hyperprolactinemia may suppress hypothalamic GnRH, resulting in reduced pituitary gonadotropin secretion This, in turn, may inhibit reproductive function by impairing gonadal steroidogenesis in both female and male patients. RISPERIDONE has been shown to elevate prolactin levels in children and adolescents as well as in adults.
Risperidone is associated with hyperprolactinemia (elevated prolactin levels), which may lead to various symptoms such as galactorrhea, amenorrhea, gynecomastia, and impotence. The elevation of prolactin levels persists during chronic administration of Risperidone. This effect is observed in both adults and children/adolescents, and is dose-dependent, with higher doses resulting in greater increases in prolactin levels [1] [2].
From the Research
Risperidone is associated with a high risk of hyperprolactinemia due to its potent dopamine D2 receptor blockade, and management options include switching to an antipsychotic with lower prolactin-raising potential, such as aripiprazole, or adding aripiprazole as an adjunctive treatment while continuing risperidone 3.
Key Points
- Risperidone's dopamine D2 receptor blockade reduces dopamine's inhibitory effect on prolactin secretion, leading to elevated prolactin levels.
- Symptoms of hyperprolactinemia may include galactorrhea, amenorrhea, gynecomastia, sexual dysfunction, and decreased bone mineral density.
- Management options include:
- Dose reduction if clinically feasible
- Switching to an antipsychotic with lower prolactin-raising potential (such as aripiprazole, quetiapine, or olanzapine)
- Adding aripiprazole (2.5-10 mg daily) as an adjunctive treatment while continuing risperidone
- For patients who must remain on risperidone, regular monitoring of prolactin levels is recommended at baseline and periodically thereafter.
- Symptomatic patients with significantly elevated prolactin (>100 ng/mL) should undergo additional evaluation to rule out other causes like pituitary tumors.
- Long-term management should consider bone health, with calcium and vitamin D supplementation and periodic bone density monitoring for patients on extended therapy, particularly women past menopause and older men.
Evidence
The most recent and highest quality study on this topic is from 2010, which found that adjunctive treatment with aripiprazole reduces the prolactin concentration that had been increased due to risperidone treatment, with a dose-dependent effect up to 6 mg/d of aripiprazole 4. Another study from 2008 found that switching antipsychotic drugs to aripiprazole was effective in reducing serum prolactin levels and restoring menstruation in schizophrenic patients who received prolactin-raising antipsychotics 3.
Clinical Implications
In clinical practice, it is essential to monitor prolactin levels in patients taking risperidone and to consider switching to an antipsychotic with lower prolactin-raising potential or adding aripiprazole as an adjunctive treatment if hyperprolactinemia occurs. Regular monitoring of bone health and consideration of calcium and vitamin D supplementation are also crucial for patients on extended therapy.