Resolution of risperidone-induced hyperprolactinemia with substitution of quetiapine

Giant cabergoline-resistant prolactinoma in a man who presented with a psychotic episode during treatment: a case report

Background

Prolactinomas are tumors of the pituitary gland that usually respond very well to treatment with cabergoline. Resistance to cabergoline is very rare, but when it occurs, it is a difficult problem to resolve if the tumor is inoperable.

Case presentation

A 62-year-old white man was treated for a giant macroprolactinoma detected during investigation of a subacute subdural hematoma of the left frontal lobe. The patient was treated with cabergoline for 17 years with a dose ranging from 1.0 mg to 3.5 mg per week. We were not able to normalize his prolactin level, which initially was 14,992 ng/ml and ultimately 1754 ng/ml. The tumor significantly shrank during the follow-up period but persisted. The patient had cardiac valvulopathies that did not worsen. He had an ischemic stroke and developed a psychotic condition that was successfully treated by lowering the cabergoline and administering quetiapine and mirtazapine together. This regimen led to a small increase in the patient’s prolactin that returned to previous levels and remained as such until the last medical evaluation. The tumor continued to shrink and had a cystic degeneration in the last evaluation.

Conclusions

Combined use of cabergoline with quetiapine and mirtazapine to treat a psychotic crisis may have contributed to shrinking the tumor in our patient because these antipsychotics have action mediated by growth factors that interfere with growth of pituitary tumors.

Controversial issues in the management of hyperprolactinemia and prolactinomas - An overview by the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism

Prolactinomas are the most common pituitary adenomas (approximately 40% of cases), and they represent an important cause of hypogonadism and infertility in both sexes. The magnitude of prolactin (PRL) elevation can be useful in determining the etiology of hyperprolactinemia. Indeed, PRL levels > 250 ng/mL are highly suggestive of the presence of a prolactinoma. In contrast, most patients with stalk dysfunction, drug-induced hyperprolactinemia or systemic diseases present with PRL levels < 100 ng/mL. However, exceptions to these rules are not rare. On the other hand, among patients with macroprolactinomas (MACs), artificially low PRL levels may result from the so-called "hook effect". Patients harboring cystic MACs may also present with a mild PRL elevation. The screening for macroprolactin is mostly indicated for asymptomatic patients and those with apparent idiopathic hyperprolactinemia. Dopamine agonists (DAs) are the treatment of choice for prolactinomas, particularly cabergoline, which is more effective and better tolerated than bromocriptine. After 2 years of successful treatment, DA withdrawal should be considered in all cases of microprolactinomas and in selected cases of MACs. In this publication, the goal of the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism (SBEM) is to provide a review of the diagnosis and treatment of hyperprolactinemia and prolactinomas, emphasizing controversial issues regarding these topics. This review is based on data published in the literature and the authors' experience.

Challenges and pitfalls in the diagnosis of hyperprolactinemia

The definition of the etiology of hyperprolactinemia often represents a great challenge and an accurate diagnosis is paramount before treatment. Although prolactin levels > 200-250 ng/mL are highly suggestive of prolactinomas, they can occasionally be found in other conditions. Moreover, as much as 25% of patients with microprolactinomas may present prolactin levels < 100 ng/mL, which are found in most patients with pseudoprolactinomas, drug-induced hyperprolactinemia, or systemic diseases. On the other hand, some conditions may lead to falsely low PRL levels, particularly the so-called hook effect, that is an assay artifact caused by an extremely high level of PRL, and can be confirmed by repeating assay after a 1:100 serum sample dilution. The hook effect must be considered in all patients with large pituitary adenomas and PRL levels within the normal range or only modestly elevated (e.g., < 200 ng/mL). An overlooked hook effect may lead to incorrect diagnosis and unnecessary surgical intervention in patients with prolactinomas. Another important challenge is macroprolactinemia, a common finding that needs to be identified, as it usually requires no treatment. Although most macroprolactinemic patients are asymptomatic, many of them may present galactorrhea or menstrual disorders, as well as neuroradiological abnormalities, due to the concomitance of other diseases. Finally, physicians should be aware that pituitary incidentalomas are found in at least 10% of adult population.

Hyperprolactinemia associated with psychotropics--a review

INTRODUCTION

Different classes of psychotropics can cause hyperprolactinemia to varying degrees. Among antipsychotics, typical agents and risperidone are the most frequent and significant offenders. In this review we discuss the pathophysiology, offending medications, assessment and management of hyperprolactinemia.

METHODS

We did a literature review between 1976 and 2008 using PubMed, MEDLINE, PsychINFO and Cochrane database. Search terms used were prolactin, hyperprolactinemia, psychotropics, antipsychotics, typical antipsychotics, atypical antipsychotics, antidepressants and SSRIs.

RESULTS

Prolactin elevation is more common with antipsychotics than with other classes of drugs. Typical antipsychotics are more prone to cause hyperprolactinemia than atypical agents. Management options include discontinuation of offending medication, switching to another psychotropic, supplementing concurrent hormonal deficiencies and adding a dopamine agonist or aripiprazole.

CONCLUSION

Clinicians need to be alert about the potential for hyperprolactinemia and its manifestations with these medications. Prolactin levels need to be monitored and other causes of hyperprolactinemia ruled out in suspected cases.

Switching elderly patients with dementia from risperidone to quetiapine: a retrospective study

The objective of this study was to collect data on outcomes obtained when switching elderly nursing home residents with dementia from risperidone to quetiapine. Medical records were reviewed to identify dementia patients switched from risperidone to quetiapine. Clinical Global Impressions (CGI) scores assigned retrospectively (at switch and weeks 4-6) assessed treatment. Data from 15 men and 52 women (mean age, 82.8 years) were evaluated. The mean daily dose of risperidone at switch was 1.42 mg. Switching was abrupt in all but 2 patients. The mean daily dose of quetiapine after the switch was 87.3 mg. After the switch, the CGI Severity of Illness score remained unchanged, but the CGI Global Improvement score was positive. Fourteen patients reported somnolence; 3 patients discontinued quetiapine. Most patients in this study were switched from risperidone to quetiapine with no worsening of clinical status.