From the Guidelines
The patient's estrogen (E2), LH, FSH, and prolactin levels should be monitored regularly as part of a comprehensive hormonal evaluation, ideally during the early follicular phase (days 2-5) of the menstrual cycle for cycling women, or at any time for postmenopausal women or those with amenorrhea, as recommended by recent guidelines 1.
Importance of Hormonal Evaluation
These tests should be ordered together to assess the patient's hormonal status and identify potential issues. Abnormal results should prompt further investigation, such as:
- Elevated prolactin, which may indicate pituitary adenoma 1
- High FSH/LH with low estrogen, suggesting ovarian failure 1
- Low FSH/LH with low estrogen, pointing to hypothalamic-pituitary issues 1
- High estrogen with low FSH/LH, which might indicate PCOS or estrogen-producing tumors 1
Monitoring and Treatment
Regular monitoring is crucial for patients on hormone therapy to ensure optimal dosing and detect potential complications. The patient's hormonal levels can help diagnose conditions like menopause, infertility, menstrual disorders, pituitary dysfunction, and PCOS, and guide appropriate treatment decisions 1.
Key Considerations
- Prolactin measurement should be offered in patients presenting with signs or symptoms of hyperprolactinaemia, such as delayed puberty, galactorrhoea, or visual field loss 1
- Age-specific and sex-specific prolactin reference ranges should be used to diagnose hyperprolactinaemia 1
- LH and FSH levels should be measured in patients with low testosterone levels combined with low or low/normal LH levels 1
From the FDA Drug Label
Circulating estrogens modulate the pituitary secretion of the gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH), through a negative feedback mechanism. Estrogens act to reduce the elevated levels of these hormones seen in postmenopausal women.
The patient's estrogen (E2) levels will increase due to the estradiol medication. The LH (luteinizing hormone) and FSH (follicle-stimulating hormone) levels will decrease due to the negative feedback mechanism of estrogens on the pituitary secretion of these hormones. There is no direct information about the effect on prolactin levels in the provided drug label 2.
From the Research
Hormone Levels
- The patient's estrogen (E2) levels may be affected by the treatment of hyperprolactinemia, as prolactin levels can impact estrogen production 3.
- Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels may also be influenced by the treatment, as dopamine agonists such as cabergoline can reduce FSH hypersecretion 4.
- Prolactin levels can be effectively reduced using dopamine agonists such as cabergoline or bromocriptine, with cabergoline showing greater efficacy and tolerability in some studies 5, 6.
Treatment Effects
- Cabergoline treatment has been shown to induce tumor shrinkage in patients with macroprolactinomas, and can also restore the function of the pituitary ovarian axis, leading to pregnancy in some cases 5, 4.
- The effectiveness of cabergoline in reducing prolactin and FSH hypersecretion can lead to improved hormonal balance and potentially restore normal menstrual cycles 4.
- Cabergoline has been compared to bromocriptine in several studies, with results showing that cabergoline is often better tolerated and more effective in reducing prolactin levels 6, 7.
Hormonal Interactions
- The relationship between prolactin and other hormones such as estrogen, LH, and FSH is complex, and treatment of hyperprolactinemia can have varying effects on these hormones 3.
- Prolactin levels can impact the menstrual cycle and fertility, and reducing prolactin levels can lead to improved fertility outcomes 3, 4.
- The use of dopamine agonists such as cabergoline can have a positive effect on hormonal balance and fertility, but individual results may vary depending on the specific condition being treated 5, 4.