Serum prolactin concentration in patients taking neuroleptic drugs

Clinical Presentations of Drug-Induced Hyperprolactinaemia: A Literature Review

Screening for drug-induced hyperprolactinaemia, a condition characterised by higher-than-normal levels of serum prolactin induced by drug treatments, requires a comprehensive understanding of the clinical presentations and long-term complications of the condition. Using two databases, Embase and MEDLINE, we summarised the available evidence on the clinical presentations and long-term complications of drug-induced hyperprolactinaemia. Clinical and observational studies reporting on drug treatments known or suspected to induce hyperprolactinaemia were included. Database searches were limited to the English language; no date or geographic restrictions were applied. Fifty studies were identified for inclusion, comprising a variety of study designs and patient populations. Most data were reported in patients treated with antipsychotics, but symptoms were also described among patients receiving other drugs, such as prokinetic drugs and antidepressants. Notably, the diagnosis of drug-induced hyperprolactinaemia varied across studies since a standard definition of elevated prolactin levels was not consistently applied. Frequent clinical presentations of hyperprolactinaemia were menstrual cycle bleeding, breast or lactation disorders, and sexual dysfunctions, described in 80% (40/50), 74% (37/50), and 42% (21/50) of the included studies, respectively. In the few studies reporting such symptoms, the prevalence of vaginal dryness impacted up to 53% of females, and infertility in both sexes ranged from 15 to 31%. Clinicians should be aware of these symptoms related to drug-induced hyperprolactinaemia when treating patients with drugs that can alter prolactin levels. Future research should explore the long-term complications of drug-induced hyperprolactinaemia and apply accepted thresholds of elevated prolactin levels (i.e., 20 ng/mL for males and 25 ng/mL for females) to diagnose hyperprolactinaemia as a drug-induced adverse event.Trial Registration PROSPERO International Prospective Register Of Systematic Reviews (CRD42021245259).

Treatments of psychiatric disorders, hyperprolactinemia and dopamine agonists

While the prevalence of hyperprolactinemia under antidepressants is very low, its prevalence under antipsychotics, particularly of the first generation, is high. Antipsychotics act by blocking dopamine activity at the level of the dopamine type 2 receptor (D2R). When prolactin levels exceed 80-100 ng/ml, a pituitary adenoma must be ruled out by MRI. Treatment of hyperprolactinemia is necessary only in cases with clinical symptoms of hypogonadism. Three treatment options are possible: switch to a less hyperprolactinemic antipsychotic, sex steroid supplementation or dopamine agonist (which normalizes prolactin levels in only half of cases). Fortunately, psychotic exacerbation due to the opposing effects of antipsychotics and dopamine agonists on the D2R seems very rare. When a patient presents with a macroprolactinoma, particularly with optic chiasm compression, surgery or dopamine agonists may be proposed. The agonists are effective in reducing tumor mass and improving visual defects in the majority of patients but rarely normalize prolactin levels.

Pitfalls in the Diagnostic Evaluation of Hyperprolactinemia

An appropriate diagnostic evaluation is essential for the most appropriate treatment to be performed. Currently, macroprolactinemia is the third most frequent cause of nonphysiological hyperprolactinemia after drugs and prolactinomas. Up to 40% of macroprolactinemic patients may present with hypogonadism symptoms, infertility, and/or galactorrhea. Thus, the screening for macroprolactin is indicated not only for asymptomatic subjects but also for those without an obvious cause for their prolactin (PRL) elevation. Before submitting patients to macroprolactin screening and pituitary magnetic resonance imaging, one should rule out pregnancy, drug-induced hyperprolactinemia, primary hypothyroidism, and renal failure. The magnitude of PRL elevation can be useful in determining the etiology of hyperprolactinemia. PRL values >250 ng/mL are highly suggestive of prolactinomas and virtually exclude nonfunctioning pituitary adenomas (NFPAs) and other sellar masses as the etiology of hyperprolactinemia. However, they can also be found in subjects with macroprolactinemia, drug-induced hyper-prolactinemia or chronic renal failure. By contrast, most patients with NFPAs, drug-induced hyperprolactinemia, macroprolactinemia, or systemic diseases present with PRL levels <100 ng/mL. However, exceptions to these rules are not rare. Indeed, up to 25% of patients harboring a microprolactinoma or a cystic macroprolactinoma may also have PRL <100 ng/mL. Falsely low PRL levels may result from the so-called "hook effect," which should be considered in all cases of large (≥3 cm) pituitary adenomas associated with normal or mildly elevated PRL levels (≤250 ng/mL). The hook effect may be unmasked by repeating PRL measurement after a 1:100 serum sample dilution.

Antipsychotic-induced hyperprolactinaemia: case studies and review

Antipsychotics are a known cause of hyperprolactinaemia and can be associated with significant health issues in short term and long term. The effects vary with gender and age of the individual and can contribute towards non-concordance and hence relapse in mental health of our patients. Clinicians need to educate the patients about this significant side effect of not only antipsychotic medications but other medications causing hyperprolactinaemia commonly prescribed in primary care.

Risk of hyperprolactinemia and sexual side effects in males 10-20 years old diagnosed with autism spectrum disorders or disruptive behavior disorder and treated with risperidone

OBJECTIVE

The aim of this study was to investigate the long-term treatment effects of risperidone on prolactin levels and prolactin-related side effects in pubertal boys with autism spectrum disorders (ASD) and disruptive behavior disorders (DBD).

METHOD

Physical healthy 10-20-year-old males with ASD (n=89) and/ or DBD (n=9) chronically treated (mean 52 months, range 16-126 months) with risperidone (group 1, n=51) or not treated with any antipsychotic (group 2, n=47) were recruited to this observational study from the child psychiatry outpatient clinic. Morning non-fasting serum prolactin levels were measured and prolactin-related side effects were assessed by means of questionnaires and physical examination. Group differences were tested with Student's t, χ(2), Fisher exact, and Mann-Whitney tests, and logistic regression analysis, according to the type and distribution of data.

RESULTS

Hyperprolactinemia was present in 47% of subjects in group 1 but only in 2% of subjects in group 2 (odds ratio 71.9; 95% CI, 7.7; 676.3). Forty-six percent of subjects in group 1 had asymptomatic hyperprolactinemia. Current risperidone dose and 9-OH risperidone plasma level were significant predictors of hyperprolactinemia (p=0.035 and p=0.03, respectively). Gynecomastia and sexual dysfunction were present in 43% and 14% of the subjects in group 1, respectively, compared with 21% and 0% of subjects in group 2 (p=0.05 and p=0.01). Gynecomastia was not significantly associated with hyperprolactinemia.

CONCLUSIONS

Hyperprolactinemia is a common side effect in young males treated over the long term with risperidone. Young males treated with risperidone are more likely to report diminished sexual functioning than are those not treated with antipsychotics.

A review of hyperprolactinaemia and severe mental illness: Are there implications for clinical biochemistry?

Hyperprolactinaemia is a common adverse event reported in association with treatments used in schizophrenia and bipolar disorder. Recent data are suggestive that hyperprolactinaemia may have a range of significant short-and long-term clinical consequences. The objective of this review is to examine the causes, frequency and clinical consequences of hyperprolactinaemia in the severely mentally ill (SMI) with a focus on patients taking antipsychotic medications. A Medline search was carried out to identify relevant publications. Reference lists from previous review articles were also examined to search for additional data. Hyperprolactinaemia may be one of the most common adverse events associated with some antipsychotic medications. Precise rates with individual drugs had however until recently been poorly categorized. The relationship between hyperprolactinaemia and adverse outcomes in the SMI population appears similar to that in the general population. Adverse outcomes (such as sexual dysfunction) can occur acutely and in the longer term (bone fractures and possibly breast cancer), but the precise link between degree and length of hyperprolactinaemia and adverse outcome remains to be established. In conclusion, hyperprolactinaemia is a common treatment-emergent adverse event of some antipsychotic medications and may have clinical consequences. Physicians must balance the benefits and risks of treatment when determining appropriate therapy for individual patients.

Treatment response in psychotic patients classified according to social and clinical needs, drug side effects, and previous treatment; a method to identify functional remission

BACKGROUND

Various approaches have been made over the years to classify psychotic patients according to inadequate treatment response, using terms such as treatment resistant or treatment refractory. Existing classifications have been criticized for overestimating positive symptoms; underestimating residual symptoms, negative symptoms, and side effects; or being to open for individual interpretation. The aim of this study was to present and evaluate a new method of classification according to treatment response and, thus, to identify patients in functional remission.

METHOD

A naturalistic, cross-sectional study was performed using patient interviews and information from patient files. The new classification method CANSEPT, which combines the Camberwell Assessment of Need rating scale, the Udvalg for Kliniske Undersøgelser side effect rating scale (SE), and the patient's previous treatment history (PT), was used to group the patients according to treatment response. CANSEPT was evaluated by comparison of expected and observed results.

RESULTS

In the patient population (n = 123), the patients in functional remission, as defined by CANSEPT, had higher quality of life, fewer hospitalizations, fewer psychotic symptoms, and higher rate of workers than those with the worst treatment outcome.

CONCLUSION

In the evaluation, CANSEPT showed validity in discriminating the patients of interest and was well tolerated by the patients. CANSEPT could secure inclusion of correct patients in the clinic or in research.

Diagnosis and treatment of prolactinomas

Prolactinomas account for approximately 40% of all pituitary adenomas. Hyperprolactinemia causes hypogonadism, infertility and galactorrhea. Macroprolactinomas may cause signs of local expansion, such as headache, visual field defects and paresis of oculomotor nerves during suprasellar and parasellar extensions. Compression of healthy pituitary tissue together with the blockade of the flow of hypothalamic released hormones to the pituitary by macroprolactinomas results in the development of hypopituitarism. The aim of treatment is restoration of hypogonadism and fertility in the microprolactinoma patients, as well as tumor shrinkage in macroprolactinoma patients. Primary therapy for prolactinomas is pharmacological treatment with dopamine agonists (DAs). However, surgical or radiation treatment is recommended for prolactinoma patients resistant or intolerant to DAs. In patients with long-term normoprolactinemia and significant tumor shrinkage, a trial of tapering and discontinuation of medical therapy is possible. After discontinuation of DAs, a long-term follow-up is necessary. In cases of recurrence displaying hyperprolactinemia and tumor enlargement, treatment must be resumed.

Clinical questions and uncertainty--prolactin measurement in patients with schizophrenia and bipolar disorder

Many antipsychotic medications have the potential to raise prolactin levels leading to a range of negative consequences. In addition to symptoms such as gynaecomastia, galactorrhoea, menstrual irregularities and sexual dysfunction it is becoming clear that there are a number of important and potentially serious long-term consequences, including a loss of bone mineral density and a possible association with the development of breast cancer. It is clear, therefore, that the tendency to raise prolactin should be an important consideration in the use of antipsychotics but, to a large degree, this area has been neglected in clinical practice and research when compared with other potential adverse effects. We consider some of the practical clinical issues in prolactin measurement and the management of high results. We will identify the areas of uncertainty that remain for clinicians and consider the practical questions that future research should address.

Drugs and prolactin

Medications commonly cause hyperprolactinemia and their use must be differentiated from pathologic causes. The most common medications to cause hyperprolactinemia are the antipsychotic agents, although some of the newer atypical antipsychotics do not do so. Other medications causing hyperprolactinemia include antidepressants, antihypertensive agents, and drugs which increase bowel motility. Often, the medication-induced hyperprolactinemia is symptomatic, causing galactorrhea, menstrual disturbance, and erectile dysfunction. In the individual patient, it is important differentiate hyperprolactinemia due to a medication from a structural lesion in the hypothalamic-pituitary area. This can be done by stopping the medication temporarily to determine if the prolactin (PRL) levels return to normal, switching to another medication in the same class which does not cause hyperprolactinemia (in consultation with the patient's physician and/or psychiatrist), or by performing an MRI or CT scan. If the hyperprolactinemia is symptomatic, management strategies include switching to an alternative medication which does not cause hyperprolactinemia, using estrogen/testosterone replacement, or cautiously adding a dopamine agonist.

Drug treatment of hyperprolactinemia

Medical treatment of hyperprolactinemia is based upon use of dopamine agonists (DA): bromocriptine, lisuride, quinagolide and cabergoline. In over 80% of cases, these drugs induce normal prolactinemia and ovulatory cycles. In resistant cases, the DA should be changed. Tolerance may occasionally be poor, particularly with bromocriptine, which appears less well-tolerated than quinagolide and than cabergoline above all. In the event of intolerance to a given DA, another should be tried. In patients with macroprolactinoma treated with DA, MRI monitoring should be carried out after 3 months of treatment to verify tumor size reduction, then after 1 year, yearly for the next 5 years and once every 5 years if adenoma size is stable. In cases of microprolactinoma, control under treatment is pointless. MRI may be performed after 1 year and then after 5 years. Once normal prolactin levels have been achieved, attempts may be made to stop the treatment. When a prolonged treatment is interrupted, especially with cabergoline, progressive increase in serum prolactin and return of hyperprolactinemia symptoms are seen in only around 20-30% of cases, particularly when residual adenoma exists after prolonged treatment. Nevertheless, prolactin levels should continue to be monitored after discontinuation of DA, possibly with MRI monitoring, since prolactin levels may rise again after a number of months or years. When normal prolactin levels have been achieved with DA, another solution consists in reducing the dose or dosing frequency of DA in steps to the lowest effective dose consistent with maintenance of normal prolactin levels and stable adenoma size. For drug-induced hyperprolactinemia, where the causative medication cannot be withdrawn, it is often pointless and possibly even dangerous to administer a DA. It is therefore necessary to check for absence of pituitary adenoma and where necessary, begin treatment with sex steroids so as to ensure satisfactory impregnation with sex steroids and avoid osteoporosis. For macroprolactinoma, the first-line treatment is drug therapy with DA. At present, there is no evidence to suggest that prior treatment with DA can modify the outcome of surgery. With microprolactinoma, DA treatment offers a good first-line therapeutic option but surgery may also be useful. DAs for microprolactinoma may be withdrawn after menopause.

Medication-induced hyperprolactinemia

Medication use is a common cause of hyperprolactinemia, and it is important to differentiate this cause from pathologic causes, such as prolactinomas. To ascertain the frequency of this clinical problem and to develop treatment guidelines, the medical literature was searched by using PubMed and the reference lists of other articles dealing with hyperprolactinemia due to specific types of medications. The medications that most commonly cause hyperprolactinemia are antipsychotic agents; however, some newer atypical antipsychotics do not cause this condition. Other classes of medications that cause hyperprolactinemia include antidepressants, antihypertensive agents, and drugs that increase bowel motility. Hyperprolactinemia caused by medications is commonly symptomatic, causing galactorrhea, menstrual disturbance, and impotence. It is Important to ensure that hyperprolactinemia in an Individual patient is due to medication and not to a structural lesion in the hypothalamic/pituitary area; this can be accomplished by (1) stopping the medication temporarily to determine whether prolactin levels return to normal, (2) switching to a medication that does not cause hyperprolactinemia (in consultation with the patient's psychiatrist for psychoactive medications), or (3) performing magnetic resonance imaging or computed tomography of the hypothalamic/pituitary area. If the patient's hyperprolactinemia is symptomatic, treatment strategies include switching to an alternative medication that does not cause hyperprolactinemia, using estrogen or testosterone replacement, or, rarely, cautiously adding a dopamine agonist.

The effect of atypical antipsychotic agents on prolactin levels in children and adolescents

This report is a review of the available literature on the effect of atypical antipsychotic agents on prolactin in children and adolescents. Fourteen reports are reviewed. Most reports (79%) have included adolescents. Three reports (21%) consisted of children only, while 7 reports (50%) included only adolescents. A total of 4 reports (29%) included both children and adolescents. The total number of subjects listed in all the reports is 276, while only 49 of the individuals on atypical neuroleptics had prolactin elevations clearly identified as outside of the normal range. The details of the reports are provided by individual atypical antipsychotic agent. Clinical implications, such as the potential impact of hyperprolactinemia on bone density, osteoporosis, gynecomastia, galactorrhea, and weight gain, are presented. Discussion of pertinent medical differential and treatment options are also reported.

Antipsychotic-induced hyperprolactinaemia: mechanisms, clinical features and management

Hyperprolactinaemia is an important but neglected adverse effect of antipsychotic medication. It occurs frequently with conventional antipsychotics and some atypical antipsychotics (risperidone and amisulpride) but is rare with other atypical antipsychotics (aripiprazole, clozapine, olanzapine, quetiapine, ziprasidone). For this reason the terms 'prolactin-sparing' and 'prolactin-raising' are more useful than 'atypical' and 'conventional' when considering the effect of antipsychotic drugs on serum prolactin. During antipsychotic treatment prolactin levels can rise 10-fold or more above pretreatment values. In a recent study approximately 60% of women and 40% of men treated with a prolactin-raising antipsychotic had a prolactin level above the upper limit of the normal range. The distinction between asymptomatic and symptomatic hyperprolactinaemia is important but is often not made in the literature. Some symptoms of hyperprolactinaemia result from a direct effect of prolactin on target tissues but others result from hypogonadism caused by prolactin disrupting the normal functioning of the hypothalamic-pituitary-gonadal axis. Symptoms of hyperprolactinaemia include gynaecomastia, galactorrhoea, sexual dysfunction, infertility, oligomenorrhoea and amenorrhoea. These symptoms are little researched in psychiatric patients. Existing data suggest that they are common but that clinicians underestimate their prevalence. For example, well conducted studies of women treated with conventional antipsychotics have reported prevalence rates of approximately 45% for oligomenorrhoea/amenorrhoea and 19% for galactorrhoea. An illness-related under-function of the hypothalamic-pituitary-gonadal axis in female patients with schizophrenia may also contribute to menstrual irregularities. Long-term consequences of antipsychotic-related hypogonadism require further research but are likely and include premature bone loss in men and women. There are conflicting data on whether hyperprolactinaemia is associated with an increased risk of breast cancer in women. In patients prescribed antipsychotics who have biochemically confirmed hyperprolactinaemia it is important to exclude other causes of prolactin elevation, in particular tumours in the hypothalamic-pituitary area. If a patient has been amenorrhoeic for 1 year or more, investigations should include bone mineral density measurements. Management should be tailored to the individual patient. Options include reducing the dose of the antipsychotic, switching to a prolactin-sparing agent, prescribing a dopamine receptor agonist and prescribing estrogen replacement in hypoestrogenic female patients. The efficacy and risks of the last two treatment options have not been systematically examined. Antipsychotic-induced hyperprolactinaemia should become a focus of interest in the drug treatment of psychiatric patients, particularly given the recent introduction of prolactin-sparing antipsychotics. Appropriate investigations and effective management should reduce the burden of adverse effects and prevent long-term consequences.

Medical management of prolactin-secreting pituitary adenomas

Prolactinomas are a common cause of reproductive/sexual dysfunction. Once other causes of hyperprolactinemia have been excluded with a careful history and physical examination, routine chemistries, a pregnancy test and a TSH, imaging with MRI or CT will delineate the size and extent of the tumor. Medical therapy is the initial treatment of choice. When infertility is the primary indication for treatment, bromocriptine use has an extensive safety experience and is preferred. However, for other indications, cabergoline appears to be more efficacious and better tolerated. Transsphenoidal surgery remains an option, especially for patients with microadenomas, when medical therapy is ineffective.