Efficacy and safety of dopamine agonists in patients treated with antipsychotics and presenting a macroprolactinoma

In patients treated with antipsychotics, the rare occurrence of a macroprolactinoma represents a therapeutic challenge.

Our aim was to evaluate the efficacy and psychiatric safety of dopamine agonists (DAs) prescribed for large macroprolactinomas in patients with psychosis treated with antipsychotics.

This was a multicenter (France and Belgium) retrospective study.

Eighteen patients treated with antipsychotics were included.

Under DA, median PRL levels decreased from 1247 (117-81 132) to 42 (4-573) ng/mL (P = 0.008), from 3850 (449-38 000) to 141 (60-6000) ng/mL (P = 0.037) and from 1664 (94-9400) to 1215 (48-5640) ng/mL (P = 0.56) when given alone (n = 8), before surgery (n = 7), or after surgery (n = 6), respectively. The prolactinoma median largest diameter decreased by 28% (0-57) in patients under DAs alone (P = 0.02) but did not change when given after surgery. Optic chiasm decompression was achieved in 82% of patients. Five patients (28%) were admitted for psychotic relapse while receiving DAs (but three of them had stopped antipsychotic treatment at that time). A more severe underlying psychosis, rather than the DA treatment itself, may explain such psychiatric admissions.

Even if the DA efficacy on PRL levels and tumor volume in patients with macroprolactinoma under antipsychotic drugs is less impressive than that typically observed, it may be considered satisfactory for half of our patients, particularly in cases of optic chiasm compression. Psychotic exacerbation was unusual in these patients, occurring mostly in those with the most severe psychotic forms. DAs may therefore be used as antitumor treatment for macroprolactinoma in patients with visual involvement, severe headaches or invasion into the skull base who receive antipsychotics.