From the Guidelines
Prolactin levels should be repeated 3-6 months after starting cabergoline treatment for macroprolactinomas, and as clinically indicated for microprolactinomas, with consideration of tapering medication after 2 years of therapy if prolactin levels are normalized and there is no visible tumor remnant on MRI 1. When managing patients with prolactinomas, it is essential to monitor prolactin levels regularly to assess the effectiveness of treatment and potential recurrence.
- For patients with macroprolactinomas, prolactin levels should be repeated 3-6 months after initiating treatment with dopamine agonists like cabergoline 1.
- For patients with microprolactinomas, repeat testing should occur as clinically indicated, taking into account factors such as symptoms, tumor size, and prolactin levels 1.
- In patients who achieve normal prolactin levels and tumor shrinkage, medication can be tapered after 2 years of therapy, with follow-up testing 4-8 weeks after dose reduction 1. Key considerations in interpreting prolactin levels include:
- Diurnal variation, with higher levels during sleep 1
- Transient elevations due to stress, exercise, or breast stimulation 1
- The need for age-specific and sex-specific reference ranges, and exclusion of confounding conditions such as hypothyroidism or medication use 1 By carefully monitoring prolactin levels and adjusting treatment accordingly, clinicians can optimize outcomes for patients with prolactinomas, minimizing the risk of recurrence and maximizing quality of life.
From the Research
Prolactin Level Repeated Measurements
- Prolactin levels should be repeated after three months of stable dose treatment with antipsychotic-drugs, or if any clinical feature of hyperprolactinemia appears 2.
- If a patient prescribed antipsychotic-drugs has a confirmed prolactin level above the normal range, it is necessary to exclude other causes of hyperprolactinemia 2.
- Serial prolactin sampling may be a useful test to detect artefactual hyperprolactinemias, thus avoiding unnecessary additional tests and treatments 3.
- Prolactin levels should be measured at baseline before beginning a treatment with antipsychotic agents, and monitored during treatment to minimize the risk of hyperprolactinemia 2, 4.
Timing of Prolactin Level Measurements
- Prolactin levels should be measured after a 30min rest to avoid stress, which may increase prolactin levels 3.
- Prolactin levels can be measured at any time, but it is recommended to measure them in the morning, when prolactin levels are typically at their highest 3.
Special Considerations
- In premenopausal women with psychosis, adjunct aripiprazole can reduce prolactin and prolactin-related adverse effects, such as galactorrhea, amenorrhea, oligomenorrhea, or sexual dysfunction 5.
- Dopamine agonists, such as cabergoline, can be effective in reducing prolactin levels and persistent hyperprolactinemia, with cabergoline proving more efficacious than bromocriptine 6.