The efficacy and tolerability of long-term cabergoline therapy in hyperprolactinaemic disorders: an open, uncontrolled, multicentre study. European Multicentre Cabergoline Study Group

Kappa opioid receptor agonists produce sexually dimorphic and prolactin-dependent hyperalgesic priming

ABSTRACT

Repeated stress produces hyperalgesic priming in preclinical models, but underlying mechanisms remain uncertain. As stress engages kappa opioid receptors (KORs), we hypothesized that repeated administration of KOR agonists might mimic, in part, stress-induced hyperalgesic priming. The potential contribution of circulating prolactin (PRL) and dysregulation of the expression of PRL receptor (PRLR) isoforms in sensory neurons after KOR agonist administration was also investigated. Mice received 3 daily doses of U-69593 or nalfurafine as a "first-hit" stimulus followed by assessment of periorbital tactile allodynia. Sixteen days after the first KOR agonist administration, animals received a subthreshold dose of inhalational umbellulone, a TRPA1 agonist, as the second-hit stimulus and periorbital allodynia was assessed. Cabergoline, a dopamine D2 receptor agonist, was used to inhibit circulating PRL in additional cohorts. Prolactin receptor isoforms were quantified in the V1 region of the trigeminal ganglion after repeated doses of U-69593. In both sexes, KOR agonists increased circulating PRL and produced allodynia that resolved within 14 days. Hyperalgesic priming, revealed by umbellulone-induced allodynia in animals previously treated with the KOR agonists, also occurred in both sexes. However, repeated U-69593 downregulated the PRLR long isoform in trigeminal neurons only in female mice. Umbellulone-induced allodynia was prevented by cabergoline co-treatment during priming with KOR agonists in female, but not male, mice. Hyperalgesic priming therefore occurs in both sexes after either biased or nonbiased KOR agonists. However, a PRL/PRLR-dependence is observed only in female nociceptors possibly contributing to pain in stress-related pain disorders in females.

How to manage intolerance to dopamine agonist in patients with prolactinoma

PURPOSE

Dopamine agonists (DA) are the gold-standard for prolactinoma and hyperprolactinemia treatment. Intolerance to DA leading to drug drop out occurs in 3 to 12% of cases. We provide here a review of published data about DA intolerance and present a case report concerning the use of intravaginal cabergoline.

METHODS

We review the literature on the definition, the pathogenesis, frequency and management of DA intolerance. In addition, the review provides strategies to enhance tolerability and avoid precocious clinical treatment withdrawal.

RESULTS

Cabergoline is often cited as the most tolerable DA and its side effects tend to ameliorate within days to weeks. Restarting the same drug at a lower dose or switching to another DA can be used in cases of intolerance. The vaginal route can be tried specifically if there are gastrointestinal side effects in the oral administration. Symptomatic treatment could be attempted, although mainly based on a strategy used in other diseases.

CONCLUSIONS

Due to limited data, no guidelines have been developed for the management of intolerance in DA treatment. The most frequent management is to perform transsphenoidal surgery. Nevertheless, this manuscript provides data derived from published literature and expert opinion, suggesting new approaches to this clinical issue.

Surgical outcomes of medically failed prolactinomas: a systematic review and meta-analysis

PURPOSE

In Prolactinomas, surgery or radiation are reserved for DA failure due to tumor resistance, intolerance to medication-induced side-effects, or patient preference. This systematic review and meta-analysis summarizes the currently available literature regarding the effectiveness of surgery to treat prolactinomas in patients who have failed DA therapy.

METHOD

A literature search was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for studies that reported outcomes of medically resistant and intolerant prolactinoma treated surgically.

RESULTS

10 articles (Total N = 816, Surgery N = 657) met the inclusion criteria. 38% of patients who underwent surgery following DA failure achieved remission without need for further treatment (p < 0.001, I² = 67.09%) with a median follow-up of 49.2 +/- 40 months. 62% achieved remission with multimodal treatment (p < 0.001, I² = 93.28%) with a median follow-up of 53 +/- 39.8 months. 16% of cases demonstrated recurrence after early remission (p = 0.02, I² = 62.91%) with recurrence occurring on average at 27 +/- 9 months. Overall, 46% of patients required reinstitution of postoperative DA therapy at last follow up (p < 0.001, I² = 82.57%). Subgroup analysis of macroprolactinoma and microprolactinoma has demonstrated that there is no statistical significance in achieving long-term remission with surgery stand-alone in macroprolactinoma group (p = 0.49) although 43% of patients were able to achieve remission with multimodal therapy at last follow-up in the same group (p < 0.001, I² = 86.34%).

CONCLUSIONS

This systematic review and meta-analysis revealed 38% of operated patients achieved remission, while 62% achieved remission when additional modes of therapy were implemented. Therefore, although surgery has not been initial therapeutic choice for prolactinoma, it plays a significant role in medically failed prolactinoma care.

Treatment of hyperprolactinemia: A single-institute experience

BACKGROUND

Dopamine agonists such as bromocriptine and cabergoline have been found to be an effective treatment for hyperprolactinemia, not only inducing adenoma shrinkage but also lowering serum prolactin levels. Among known dopamine agonists, cabergoline is the drug of choice due to its enhanced tolerability compared with bromocriptine. This study aimed to evaluate cabergoline's effectiveness, along with transsphenoidal surgery, in the treatment of hyperprolactinemia.

METHODS

We retrieved all patients with a diagnosis of prolactinoma who were treated in our hospital during 2000-2018. A total of 208 patients were enrolled in the analysis after applying exclusion criteria. Patients were divided into four groups according to the treatments received. The demographic data, dosage and duration of cabergoline, and serum prolactin levels at different time points were collected for analysis.

RESULTS

Normalization was achieved in 59 patients (83.10%) within a short median duration of 2.80 months among those treated with cabergoline only. Although cabergoline alone was effective and well-tolerated, our data showed that long-term remission rates were more favorable when surgery was involved. The long-term remission rate of all patients enrolled was 53.8% (112 patients among 208 patients). The long-term remission rates for the different treatment groups were 17.8% (8 of 45 patients) in Group 1 (Operation→Drug), 83.3% (5 of 6 patients) in Group 2 (Drug→Operation), 79.0% (68 of 86 patients) in Group 3 (Operation only), and 43.7% (31 of 71 patients) in Group 4 (Drug only).

CONCLUSION

Cabergoline has been demonstrated to be effective and should be considered as a first-line treatment for hyperprolactinemia. In our study, transsphenoidal surgery was also demonstrated to achieve good results compared with medical treatment. Surgical intervention may resurface as an alternative first-line treatment. When used in combination with cabergoline, surgery offers a higher disease remission rate than either drug or operation alone.

The PRolaCT studies - a study protocol for a combined randomised clinical trial and observational cohort study design in prolactinoma

Background

First-line treatment for prolactinomas is a medical treatment with dopamine agonists (DAs), which effectively control hyperprolactinaemia in most patients, although post-withdrawal remission rates are approximately 34%. Therefore, many patients require prolonged DA treatment, while side effects negatively impact health-related quality of life (HRQoL). Endoscopic transsphenoidal resection is reserved for patients with severe side effects, or with DA-resistant prolactinoma. Surgery has a good safety profile and high probability of remission and may thus deserve a more prominent place in prolactinoma treatment. The hypothesis for this study is that early or upfront surgical resection is superior to DA treatment both in terms of HRQoL and remission rate in patients with a non-invasive prolactinoma of limited size.

Methods

We present a combined randomised clinical trial and observational cohort study design, which comprises three unblinded randomised controlled trials (RCTs; PRolaCT-1, PRolaCT-2, PRolaCT-3), and an observational study arm (PRolaCT-O) that compare neurosurgical counselling, and potential subsequent endoscopic transsphenoidal adenoma resection, with current standard care. Patients with a non-invasive prolactinoma (< 25 mm) will be eligible for one of three RCTs based on the duration of pre-treatment with DAs: PRolaCT-1: newly diagnosed, treatment-naïve patients; PRolaCT-2: patients with limited duration of DA treatment (4–6 months); and PRolaCT-3: patients with persisting prolactinoma after DA treatment for > 2 years. PRolaCT-O will include patients who decline randomisation, due to e.g. a clear treatment preference. Primary outcomes are disease remission after 36 months and HRQoL after 12 months.

Discussion

Early or upfront surgical resection for patients with a limited-sized prolactinoma may be a reasonable alternative to the current standard practice of DA treatment, which we will investigate in three RCTs and an observational cohort study. Within the three RCTs, patients will be randomised between neurosurgical counselling and standard care. The observational study arm will recruit patients who refuse randomisation and have a pronounced treatment preference. PRolaCT will collect randomised and observational data, which may facilitate a more individually tailored practice of evidence-based medicine.

Trial registration

US National Library of Medicine registry (ClinicalTrials.gov) NCT04107480. Registered on 27 September 2019, registered retrospectively (by 2 months).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05604-y.

The prolactin receptor long isoform regulates nociceptor sensitization and opioid-induced hyperalgesia selectively in females

Pain is more prevalent in women for reasons that remain unclear. We have identified a mechanism of injury-free nociceptor sensitization and opioid-induced hyperalgesia (OIH) promoted by prolactin (PRL) in females. PRL signals through mutually inhibitory long (PRLR-L) and short (PRLR-S) receptor isoforms, and PRLR-S activation induces neuronal excitability. PRL and PRLR expression were higher in females. CRISPR-mediated editing of PRLR-L promoted nociceptor sensitization and allodynia in naïve, uninjured female mice that depended on circulating PRL. Opioids, but not trauma-induced nerve injury, decreased PRLR-L promoting OIH through activation of PRLR-S in female mice. Deletion of both PRLR-L and PRLR-S (total PRLR) prevented, whereas PRLR-L overexpression rescued established OIH selectively in females. Inhibition of circulating PRL with cabergoline, a dopamine D2 agonist, up-regulated PRLR-L and prevented OIH only in females. The PRLR-L isoform therefore confers protection against PRL-promoted pain in females. Limiting PRL/PRLR-S signaling pharmacologically or with gene therapies targeting the PRLR may be effective for reducing pain in a female-selective manner.

Endoscopic Transsphenoidal Surgery of Microprolactinomas: A Reappraisal of Cure Rate Based on Radiological Criteria

BACKGROUND

Current standard treatment of microprolactinomas is dopamine agonist therapy. As this drug treatment is lifelong in up to 80% of cases, many patients consult pituitary surgeons regarding a surgical alternative.

OBJECTIVE

To identify prognostic criteria for surgical remission, we reviewed outcomes of our series of microprolactinomas treated with endoscopic transsphenoidal surgery, with a special emphasis on magnetic resonance adenoma delineation and position.

METHODS

Our study cohort comprises a single center series of 60 patients operated for histopathologically verified magnetic resonance imaging unequivocally identifiable endosellar microprolactinoma between 2003 and 2017. In 31 patients the adenoma was enclosed by pituitary gland (group ENC), in 29 patients the adenoma was located lateral to the gland adherent to the medial cavernous sinus wall (group LAT).

RESULTS

After a mean follow-up of 37 mo (range 4-143 mo), remission rate was significantly higher in adenomas enclosed by pituitary gland (group ENC) than adenomas located lateral to the gland (group LAT), with 87% vs 45%, P = .01. Intraoperatively, 4 patients showed signs of invasiveness. Preoperative prolactin levels did not differ between the groups (mean 155 and 187 ng/ml in group ENC and LAT, respectively).A binary logistic regression model revealed that only the radiological criteria applied showed a significant correlation (P = .003) with endocrine remission.

CONCLUSION

According to our results, remission rate is significantly higher in microprolactinomas enclosed by the pituitary gland. However, the decision for surgery should take into account surgeons experience and possibility of complications.

Management of Dopamine Agonist-Resistant Prolactinoma

Dopamine agonists are usually very effective in the treatment of prolactinomas. Nonetheless, a subset of individuals does not respond satisfactorily to these agents, and this resistance is characterized by failure to achieve normoprolactinemia and a 30% or more reduction in maximal tumor diameter (in the case of macroprolactinoma) under maximally tolerated doses. The overall prevalence of dopamine agonist resistance is 20-30% for bromocriptine (BRC) and around 10% for cabergoline (CAB). The 2 main predictive factors are male gender and tumor invasiveness. The management of drug-resistant prolactinomas includes several options. Any BRC-resistant patient should be switched to CAB which will normalize prolactin in 80% of patients. As long as adverse effects do not develop, dose escalation of CAB is reasonable, with the expectation that subsequent dose reduction will be possible. Echocardiographic monitoring is advised in such patients because of the potential association with cardiac valvular fibrosis. Also, maintaining maximal CAB doses at 3.5 mg/week may lead to progressive hormonal control in a significant proportion of patients. Complete resistance to CAB is infrequent. In a study of 122 patients with a macroprolactinoma, only 7 (6%) could not achieve control despite maximal CAB doses for > 12 months. A large resistant prolactinoma is also an indication for transsphenoidal neurosurgery, aiming at a debulking which may improve postoperative medical control. For patients who harbor aggressive prolactinomas, radiotherapy may be considered. However, normal prolactinemia will eventually occur in only one-third of patients after many years. Finally, temozolomide may be a therapeutic option in malignant/aggressive prolactinomas.

Treatment of multiresistant prolactinomas with a combination of cabergoline and octreotide LAR

BACKGROUND AND OBJECTIVES

Dopamine agonist (DA)-resistant prolactinomas are rare but they constitute a real challenge, since there are few therapeutic alternatives left for these patients.

DESIGN AND SETTING

Proof-of-concept study at a tertiary care, referral center.

PATIENTS AND METHODS

The studied population consisted of five patients (one female and four males, mean age at diagnosis 23.5 ± 19) with macroprolactinomas with persistent hyperprolactinemia and/or tumor mass despite high doses of cabergoline (CBG) and pituitary surgery, to whom 20 mg monthly of octreotide LAR was added for 6-13 months. Response was evaluated by measuring prolactin (PRL) levels and by magnetic resonance imaging. Immunohistochemistry (IHC) for pituitary hormones, Ki-67, and somatostatin receptor subtypes 2 and 5 was (SSTR2 and 5) was available in two of the subjects.

RESULTS

The addition of octreotide LAR to ongoing CBG treatment had no effect on either PRL levels or tumor size in three patients. In two of the five patients, combination treatment resulted in a significant reduction in PRL concentrations (from 7643 to 200 ng/mL and from 2587 to 470 ng/mL) as well as in adenoma size (93% reduction). IHC evaluation of tumor samples from two patients (a responder and a non-responder) revealed positive immunostaining for PRL and SSTR5 but not for other pituitary hormones or for SSTR2.

CONCLUSIONS

The addition of a somatostatin analog to ongoing CBG treatment may be effective in some patients with DA-resistant macroprolactinomas, independently of the adenoma's SSTR expression profile.

An Economic Analysis of Bromocriptine Versus Trans-Sphenoidal Surgery for the Treatment of Prolactinoma

Prolactinomas account for ∼40% of all pituitary adenomas and are important causes of infertility and gonadal dysfunction. In general, most prolactinomas are treated medically with dopaminergic agonists, while surgery is reserved for patients intolerant or nonresponsive to these medications. The aim of this study was to carry out a comparative analysis of the cost-effectiveness of medical therapy with bromocriptine and surgical therapy with trans-sphenoidal surgery. A Markov model was developed based on retrospective data from 126 patients with prolactinoma treated in our hospital between October 2008 and May 2009, and from data published previously. For patients with microadenoma, the cost of medical treatment was estimated to be ¥20,555, while the cost of surgery was calculated to be ¥22,527. For patients with macroadenoma, the cost of therapy with bromocriptine was ¥31,461 in males and ¥27,178 in females, while the cost of surgery was ¥42,357 in males and ¥44,094 in females. Sensitivity analyses (carried our using variations in patient age, bromocriptine therapeutic dose, bromocriptine maintenance dose, and the success rate of bromocriptine withdrawal) indicated that our model showed good stability, although our results were most heavily influenced by variations in the bromocriptine maintenance dose. It is concluded that, from an economic viewpoint, medical therapy with bromocriptine should be the first-line treatment option for patients with prolactinoma, irrespective of whether this is a microadenoma or macroadenoma.

THERAPY OF ENDOCRINE DISEASE: Surgery in microprolactinomas: effectiveness and risks based on contemporary literature

Microprolactinomas are the most common pituitary adenomas. In symptomatic patients, dopamine agonists are the first-line treatment of choice; when cabergoline is used, biochemical control rates between 85 and 93% have been reported. Long-term treatment is needed in most of the cases with compliance, patient convenience, and potential adverse effects representing areas requiring attention. Based on the literature published in the past 15 years, transsphenoidal surgery can lead to normal prolactin in the postoperative period in usually 71-100% of the cases with very low postoperative complication rates. Surgical expertise is the major determinant of the outcomes, and it may be a cost-effective option in young patients with life expectancy greater than 10 years (provided it is performed by experienced surgeons at high volume centers with confirmed optimal outcomes). Larger series of patients with adequate follow-up could further validate the place of transsphenoidal surgery (particularly through the endoscopic approach for which long-term results are currently limited) in the management algorithm of patients with microprolactinoma.

Challenges and controversies in the treatment of prolactinomas

Recent studies have reported a higher prevalence of pituitary tumors than previously thought. Among these tumors, prolactinomas occur in up to 66% of cases. Since the mid-1980s, the widespread use of dopamine agonists has facilitated the management of the majority of prolactinomas, allowing biological and tumoral control in most cases. The less frequent cases of resistant prolactinomas remain challenging despite a multimodal therapy approach. The understanding of genetic alterations in familial and aggressive pituitary tumors provides new perspectives in the management of some prolactinomas. Genetic screening should be considered, particularly in familial cases but also in young patients with macroprolactinomas, as some mutations can predict potential aggressiveness.

Long-term evolution and outcomes of microprolactinoma with medical treatment

INTRODUCTION

Prolactinoma is the most frequent functioning pituitary adenoma. Most commonly occurs as microprolactinoma (less than 1cm in size), which may be cured with medical therapy, but few long-term studies are available about optimal duration of treatment with dopamine agonists to ensure cure after drug discontinuation and its withdrawal without recurrence are do not report consistent results.

OBJECTIVE

To establish criteria for cure of microprolactinoma with medical treatment and to analyze the potential predictors involved.

PATIENTS

A retrospective study was conducted on 47adult women with microprolactinoma followed up between 1975 and 2010; none of them had undergone prior surgery or radiotherapy, and all of them received treatment with a dopamine agonist for at least 4years. They were divided into two groups for analysis: cured patients with at least 4years with normal prolactin levels after drug discontinuation, and not cured patients.

RESULTS

Cure was achieved in 57.4% of patients. Only age at diagnosis was a significant predictor: there were more young patients in the cured group and youngest patients needed less time to cure. Development of empty sella turcica or normal MRI were similar regarding time to cure.

CONCLUSIONS

Microprolactinoma may be cured with dopamine agonists, and life-long treatment is not required, although more than 10years may be required to achieve cure, 11,6±5,3 years in our experience.

Treatment of hyperprolactinemia: a systematic review and meta-analysis

BACKGROUND

Hyperprolactinemia is a common endocrine disorder that can be associated with significant morbidity. We conducted a systematic review and meta-analyses of outcomes of hyperprolactinemic patients, including microadenomas and macroadenomas, to provide evidence-based recommendations for practitioners. Through this review, we aimed to compare efficacy and adverse effects of medications, surgery and radiotherapy in the treatment of hyperprolactinemia.

METHODS

We searched electronic databases, reviewed bibliographies of included articles, and contacted experts in the field. Eligible studies provided longitudinal follow-up of patients with hyperprolactinemia and evaluated outcomes of interest. We collected descriptive, quality and outcome data (tumor growth, visual field defects, infertility, sexual dysfunction, amenorrhea/oligomenorrhea and prolactin levels).

RESULTS

After review, 8 randomized and 178 nonrandomized studies (over 3,000 patients) met inclusion criteria. Compared to no treatment, dopamine agonists significantly reduced prolactin level (weighted mean difference, -45; 95% confidence interval, -77 to -11) and the likelihood of persistent hyperprolactinemia (relative risk, 0.90; 95% confidence interval, 0.81 to 0.99). Cabergoline was more effective than bromocriptine in reducing persistent hyperprolactinemia, amenorrhea/oligomenorrhea, and galactorrhea. A large body of noncomparative literature showed dopamine agonists improved other patient-important outcomes. Low-to-moderate quality evidence supports improved outcomes with surgery and radiotherapy compared to no treatment in patients who were resistant to or intolerant of dopamine agonists.

CONCLUSION

Our results provide evidence to support the use of dopamine agonists in reducing prolactin levels and persistent hyperprolactinemia, with cabergoline proving more efficacious than bromocriptine. Radiotherapy and surgery are useful in patients with resistance or intolerance to dopamine agonists.

Dopamine agonist-resistant prolactinomas

The authors' object in this paper was to review the definition, epidemiology, biology, resistance mechanisms, and treatment options for dopamine agonist-resistant prolactinomas (DARPs). Prolactinomas are relatively unique among primary brain tumors in that medical treatment alone using dopamine agonists carries a high probability of disease control or even radiographic and endocrine remission, and thus has replaced surgery as the first line of therapy. Unfortunately, slightly less than 10% of patients with prolactinomas do not experience normalization of their prolactin levels in response to dopamine agonists, and harbor tumors that are resistant to dopamine agonist therapy. A literature review underscores that in male patients these DARPs are more likely to be invasive macroadenomas than dopamine agonist-responsive prolactinomas and that they are also more angiogenic, more proliferative, and more likely to exhibit cellular atypia. Estrogen receptor antagonists and temozolomide are the most commonly applied medical therapies in cases in which resection and radiosurgery have not induced remission of the hyperprolactinemia. Dopamine agonist-resistant prolactinomas exhibit aggressive behavior and tend to be large, invasive, hyperangiogenic tumors with high mitotic indices, which makes their management via surgery, radiosurgery, or alternative medical therapies challenging, thus underscoring the need for novel medical therapies or treatment regimens that target these lesions.

Effectiveness of short-term maintenance treatment with cabergoline in microadenoma-related and idiopathic hyperprolactinemia

OBJECTIVE

This study aimed to determine the effectiveness of short-term maintenance treatment with cabergoline and to find out minimum effective dosage of cabergoline during maintenance treatment for patients with microadenoma-related and idiopathic hyperprolactinemia.

STUDY DESIGN

Cabergoline was administered orally at a dose of 0.5 mg twice per week to 164 de novo hyperprolactinemic patients until serum prolactin level normalized. After this initial treatment phase, patients started on maintenance phase for which they were previously randomized. No maintenance treatment (Group I, n = 36) or cabergoline 0.5 mg (Group II, n = 46), 0.25 mg (Group III, n = 39), 0.125 mg (Group IV, n = 43) was administered twice per week for 8 weeks as maintenance treatment. Then, maintenance phase was finalized and patients were followed up for 6 months. Mean serum prolactin levels through maintenance treatment phase and follow-up period were assessed between groups and within groups.

RESULTS

Except for group I, all the groups showed a similar pattern with fast decrease of serum prolactine level during maintenance phase and slower increase during the follow-up period. Notably, the average prolactin level was significantly lower at the last follow-up visit than at the diagnosis time in all of the groups. Stable normoprolactinemia of the groups at the end of follow-up period were 47.2, 37, 48.7, and 34.9%, respectively.

CONCLUSIONS

The results indicate that short maintenance treatment in idiopathic and microadenoma-related hyperprolactinemia seems as effective as long maintenance treatment in the present study. But, further studies with larger study population and longer follow-up period are needed to make a decision about early treatment withdrawal. Also, during the maintenance treatment administration of medicine to patients should be tapered down to the lowest dose that will maintain prolactin levels normal.

Individualized high-dose cabergoline therapy for hyperprolactinemic infertility in women with micro- and macroprolactinomas

CONTEXT

Cabergoline is effective for hyperprolactinemic hypogonadism. However, the rate of cabergoline-induced pregnancy in women with prolactinoma remains unknown. Also unknown is whether cabergoline can control tumor growth and thereby achieve successful pregnancy in patients with macroprolactinomas.

METHODS

Eighty-five women with macroprolactinomas (n = 29) or microprolactinomas (n = 56) received prospective, high-dose cabergoline therapy for infertility based on individual prolactin suppression and/or tumor shrinkage. The patients included 31 bromocriptine-resistant, 32 bromocriptine-intolerant, and 22 previously untreated women. Conception was withheld until three regular cycles returned in women with microadenoma and until tumors shrank below 1.0 cm in height in women with macroadenoma. Cabergoline was withdrawn at the fourth gestational week.

RESULTS

Cabergoline normalized hyperprolactinemia and recovered the ovulatory cycle in all patients. All adenomas contracted, and 11 macroadenomas and 29 microadenomas disappeared. Eighty patients (94%) conceived 95 pregnancies, two of which were cabergoline-free second pregnancies. The dose of cabergoline at the first pregnancy was 0.25-9 mg/wk overall and 2-9 mg/wk in the resistant patients. Of the 93 pregnancies achieved on cabergoline, 86 resulted in 83 single live births, one stillbirth, and two abortions; the remaining seven were ongoing. All babies were born healthy, without any malformations. No mothers experienced impaired vision or headache suggestive of abnormal tumor reexpansion throughout pregnancy.

CONCLUSION

Cabergoline achieved a high pregnancy rate with uneventful outcomes in infertile women with prolactinoma, independent of tumor size and bromocriptine resistance or intolerance. Cabergoline monotherapy could substitute for the conventional combination therapy of pregestational surgery or irradiation plus bromocriptine in macroprolactinomas.

Prospective study of high-dose cabergoline treatment of prolactinomas in 150 patients

CONTEXT

Cabergoline fails to normalize hyperprolactinemia in a considerable proportion of prolactinomas, especially macroadenomas.

OBJECTIVE

We examined the effect of individualized high-dose cabergoline treatment on hyperprolactinemia in prolactinomas.

PATIENTS

The study included 122 women and 28 men (93 microadenomas and 57 macroadenomas). Forty-seven had undergone transsphenoidal surgery. According to the preceding medical treatment, the participants were separated into untreated (group U; n = 60), intolerant (group I; n = 64), and resistant (group R; n = 26) groups.

INTERVENTIONS

We promptly increased cabergoline dose on the basis of individual prolactin levels. Length of treatment was 1 yr.

RESULTS

Cabergoline normalized hyperprolactinemia in all patients except one. The proportion of prolactin normalization in both groups U and I was 83% at 3 months and 95% at 6 months. By contrast, that in group R was 35% at 3 months and 58% at 6 months. Mean cabergoline dose in milligrams per week at the time of prolactin normalization was 2.0 +/- 0.3 in group U, 0.9 +/- 0.1 in group I, and 5.2 +/- 0.6 in group R. Prolactin normalization rate at the 3 mg/wk dose was 84% overall but only 35% in group R. Serum progesterone or testosterone levels, diminished in 122 women or 16 men, respectively, were recovered in all except one resistant and four postmenopausal or panhypopituitary patients.

CONCLUSION

Individualized high-dose cabergoline treatment can normalize hyperprolactinemia and hypogonadism in nearly all prolactinomas irrespective of tumor size or preceding treatments. Hyperprolactinemia could be controlled in poor responders within 1 yr with doses higher than 3 mg/wk.

Operative treatment of prolactinomas: indications and results in a current consecutive series of 212 patients

OBJECTIVE

Medical therapy with dopamine agonists (DA) is the primary treatment of choice in most patients with prolactinomas. 'Classical' surgical indications are intolerance or lack of efficiency of DA therapy. Focusing on a possible shift of recent indications, we retrospectively analyzed our results of surgical treatment in prolactinomas.

PATIENTS AND METHODS

Between 1990 and 2005, we have operated on 212 consecutive patients with prolactinomas. Surgical indications were divided into 'classical' indications and 'modern' indications defined as cystic prolactinomas or patients with microprolactinomas who individually decided on a primary surgical treatment.

RESULTS

Initial overall remission was accomplished in 53.2% including giant prolactinomas. However, in microadenomas, the remission rate was significantly higher with 91.3%. Overall remission at the latest follow-up was 42.7%, but 72.5% in intrasellar tumors, 80% in cystic prolactinomas, and 84.8% in microprolactinomas. The overall recurrence rate was 18.7%. Relapse of hyperprolactinemia in microprolactinomas was 7.1%. In our series, continually less patients were surgically treated for 'classical' indications. By contrast, the number of patients who individually decided on a primary surgical therapy has increased considerably.

CONCLUSION

Remission rates after surgical treatment of prolactinomas remain excellent, particularly in microadenoma and intrasellar macroadenomas, whereas morbidity of transsphenoidal surgery is low in the hands of experienced pituitary surgeons. Our remission rates not only confirm the already interdisciplinarily accepted surgical indications, but also emphasize the value of primary transsphenoidal surgery as a discussion-worthy alternative to dopaminergic therapy in young patients with microprolactinomas or cystic tumors.

Advances in the treatment of prolactinomas

Prolactinomas account for approximately 40% of all pituitary adenomas and are an important cause of hypogonadism and infertility. The ultimate goal of therapy for prolactinomas is restoration or achievement of eugonadism through the normalization of hyperprolactinemia and control of tumor mass. Medical therapy with dopamine agonists is highly effective in the majority of cases and represents the mainstay of therapy. Recent data indicating successful withdrawal of these agents in a subset of patients challenge the previously held concept that medical therapy is a lifelong requirement. Complicated situations, such as those encountered in resistance to dopamine agonists, pregnancy, and giant or malignant prolactinomas, may require multimodal therapy involving surgery, radiotherapy, or both. Progress in elucidating the mechanisms underlying the pathogenesis of prolactinomas may enable future development of novel molecular therapies for treatment-resistant cases. This review provides a critical analysis of the efficacy and safety of the various modes of therapy available for the treatment of patients with prolactinomas with an emphasis on challenging situations, a discussion of the data regarding withdrawal of medical therapy, and a foreshadowing of novel approaches to therapy that may become available in the future.

Drug Insight: cabergoline and bromocriptine in the treatment of hyperprolactinemia in men and women

Prolactinoma is the most frequent pituitary tumor histotype. Men generally have macroadenomas whereas women generally have microadenomas. The major objectives of treating prolactinomas are to suppress excessive hormone secretion and its clinical consequences, to remove the tumor mass while preserving the residual pituitary function, and possibly to prevent disease recurrence or progression. Primary therapy of prolactinomas is based on use of dopamine-receptor agonists. Bromocriptine induces normalization of prolactin levels in 80-90% of patients with microprolactinomas and approximately 70% of those with macroprolactinomas. Tumor-mass shrinkage and improvement of visual-field defects are found in the majority of treated macroprolactinomas, but bromocriptine often causes side effects. Cabergoline is very effective and well tolerated in more than 90% of patients with either microprolactinomas or macroprolactinomas. Cabergoline treatment also induces tumor shrinkage in the majority of patients with macroprolactinomas. Tumor shrinkage is more evident if patients have not previously been treated with other dopamine agonists. Fewer results are available for men than for women, but there is no evidence that men are less responsive to dopamine agonists than are women.

Randomized controlled pilot trial of cabergoline, hydergine and levodopa/carbidopa: Los Angeles Cocaine Rapid Efficacy Screening Trial (CREST)

AIM

This study tested three dopaminergic medications against a common unmatched placebo condition: hydergine 1 mg three times daily (n = 15); levodopa/carbidopa 25/100 mg three times daily (n = 15); cabergoline 0.5 mg per week (n = 15); and placebo three times daily (n = 15) as potential pharmacotherapies for cocaine dependence.

DESIGN

The four-parallel group, Cocaine Rapid Efficacy Screening Trial (CREST) design featured a 2-week baseline period followed by randomization to an 8-week medication condition that included 1 hour per week of cognitive behavioral drug counseling. A safety evaluation was conducted 4 weeks after termination.

MEASURES

Outcomes included cocaine metabolites measured in urine, retention and self-reports for drug use, cocaine craving, clinical improvement, mood and HIV risk behaviors.

RESULTS

Participants assigned to receive cabergoline provided more urine samples negative for cocaine metabolites (42.4%) than those assigned to receive placebo (25.0%), a statistically significant difference after controlling for baseline differences in self-reported cocaine use (F = 2.95, df = 3; P = 0.05). Cabergoline-treated participants demonstrated a significant improvement over placebo from baseline to week 8 when measured using the Addiction Severity Index (ASI) employment subscale (overall change = - 0.09, SD = 0.10, t = 2.36, P < 0.05). Safety and adverse event measures showed similar rates and types of complaints by treatment condition.

CONCLUSIONS

These results, combined with the apparent safety of cabergoline when used with this population, provide empirical support for conducting a larger study of the medication.

Surgical outcomes in hyporesponsive prolactinomas: analysis of patients with resistance or intolerance to dopamine agonists

Surgery for prolactinoma patients is usually reserved for those who are intolerant of or have an inadequate response to medication. We report the results of surgical treatment in these patients.

METHODS

We retrospectively analyzed a consecutive series of patients with histopathologically confirmed prolactinomas; two patients treated with craniotomy and 77 patients with prolactinomas treated by transsphenoidal surgery between 1993 and 2003. We evaluated symptomatic patients who did not tolerate or did not respond to dopamine agonist therapy (persistent hyperprolactinemia and/or no shrinkage of tumor mass). We report remission rates, prolactin levels, and medications either not tolerated or ineffective.

RESULTS

Eighteen patients were intolerant of medical therapy (nine with macroadenomas and nine with microadenomas). Postoperatively, 12 patients (67%) achieved normalization of prolactin and relief of symptoms from surgery alone. Sixty-one patients were resistant to dopamine agonist therapy (45 with macroadenomas and 16 with microadenomas). Forty-six patients had both elevated prolactin levels and no shrinkage. 22 patients (36%) achieved normal postoperative prolactin levels. Ten of the remaining 39 patients required adjunctive medical therapy to maintain normal prolactin levels and relief of symptoms.

CONCLUSIONS

Remission through surgery was achieved in 67% (12 of 18 patients, 4 macroadenomas and 8 microadenomas) of prolactinoma patients who fail medical therapy with dopamine agonists because of intolerance to medication. Remission was also achieved in 36% (22 of 61 patients, 12 macroadenomas and 10 microadenomas) of patients who demonstrated resistance to dopamine agonist medication.

Dopamine receptor agonists for treating prolactinomas

Prolactinomas are the most common hormone-secreting pituitary tumours and cause infertility and gonadal and sexual dysfunction in both sexes. The approach to prolactinomas has changed in the last 25 years thanks to the availability of dopaminergic drugs characterised by a potent prolactin-inhibitory effect, a tumour shrinking effect associated with a satisfactory tolerability. In more recent years, cabergoline 1-[(6-allelylergolin-8beta-yl)carbonyl]-1-[3-(dimethylamino) propyl]-3-ethyl-urea an ergoline derivative with potent, selective and long-lasting inhibitory activity on prolactin release, has been used to suppress prolactin secretion in women with hyperprolactinaemia. Cabergoline was shown to be significantly more effective than bromocriptine in inducing a complete biochemical response and clinical efficacy and was better tolerated than bromocriptine in the majority of patients. Notable tumour shrinkage until tumour disappearance was observed during cabergoline treatment in most patients with macroprolactinoma and it was also proven effective in patients resistant to or with a poor response to bromocriptine. In view of the limited data on cabergoline-associated pregnancies and the long half-life of the drug, it is currently recommended that women hoping to become pregnant, once ovulatory cycles have been established, should discontinue cabergoline therapy 1 month before they intend to conceive. However, no data concerning negative effects on pregnancy or offspring have been reported. The great efficacy of this compound together with its excellent tolerability makes this drug the current treatment of choice for the majority of patients with hyperprolactinaemic disorders.

Optic chiasmal herniation--an under recognized complication of dopamine agonist therapy for macroprolactinoma

The initial presentation of macroprolactinoma with visual field impairment, especially in males, is well recognized. Successful treatment with dopamine agonist therapy is characterized by a reduction in hyperprolactinaemia and often rapid and progressive resolution of the visual impairment. A small proportion of patients may subsequently develop a secondary deterioration in both their visual fields and visual acuities despite normalization of prolactin levels and tumour shrinkage. When pituitary apoplexy can be excluded this may result from traction on the optic chiasm which is pulled down into the now partially empty sella. We report a series of seven patients in whom chiasmal traction is believed to be the cause of their secondary deterioration in visual acuity occurring after dopamine agonist therapy for macroprolactinoma. The clinical history of two patients both of whom had rapid resolution of field defect with bromocriptine therapy but subsequently developed a recurrence of their bitemporal hemianopia is detailed. In both patients MRI scanning showed not only tumour involution but also marked optic chiasm herniation into the pituitary fossa. Surgical treatment was considered too risky; but on reduction of bromocriptine dosage the field defect improved in both cases; there was a modest elevation of prolactin and a degree of tumour re-expansion. The latter is believed to have released tethering of the optic chiasm and/or its vascular supply and thus obviated the need for surgery. Regular monitoring of visual fields in patients with macroprolactinoma receiving medical treatment is therefore important. Early recognition of secondary field loss due to chiasmal herniation enables correction of the visual field loss by manipulation of the medical therapy.

Tratamento medicamentoso dos tumores hipofisários. Parte I: prolactinomas e adenomas secretores de GH

O recente desenvolvimento de novas drogas, particularmente os análogos da somatotastina (SRIFa), representou um grande progresso na terapia dos tumores hipofisários. Os SRIFa mostram-se bastante eficazes na normalização dos níveis de GH e IGF-1 em acromegálicos e podem ser uma alternativa para a cirurgia transesfenoidal, mas seu uso como terapia primária da acromegalia fica limitado pelo pequeno efeito dessas drogas na redução das dimensões do tumor. Os resultados preliminares com os antagonistas do receptor de GH, como o pegvisomant, são bastante animadores. Tais drogas permitem a normalização do IGF-1 e melhora clínica em mais de 80% dos casos; entretanto, não causam redução tumoral. Agonistas dopaminérgicos (DA) representam a terapia de escolha para microprolactinomas sintomáticos e macroprolactinomas, permitindo normalização dos níveis da prolactina e redução do volume do adenoma na maioria dos pacientes. Podem também ser eventualmente eficazes em acromegálicos, sobretudo naqueles com adenomas co-secretores de prolactina e níveis não muito elevados de GH e IGF-1. Devido a sua maior eficácia e melhor tolerabilidade, a cabergolina representa o DA de escolha para o manuseio dos prolactinomas e da acromegalia.

Cabergoline

Cabergoline (CAB) (1-[(6-allelylergolin-8 beta-yl)carbonyl]-1-[3-(dimethylamino)propyl]-3-ethyl-urea) is an ergoline derivative with potent, selective and long-lasting inhibitory activity on prolactin (PRL) secretion acting on dopamine receptors present in pituitary lactotrophes. Receptor binding studies have demonstrated that CAB has high in vitro selectivity and affinity for the subtype D2 of the dopamine receptor. In cultures of rat anterior pituitary cells, the concentrations of CAB and bromocriptine required to inhibit PRL secretory activity by 50% (IC50) were 0.1 and 3.4 nmol/l, respectively. As compared to bromocriptine, CAB was more potent in inhibiting the binding of [3H]N-n-propylnorapomorphine and it occupied the receptor for longer. These effects were observed in all areas of the rat brain. In vivo, CAB at doses of 0.125-1 mg twice weekly caused a dose-dependent suppression of PRL secretion in women with hyperprolactinaemia. CAB was shown to be significantly more effective than bromocriptine in inducing a complete biochemical response and clinical efficacy and was better tolerated than bromocriptine in the majority of patients. Notable tumour shrinkage until tumour disappearance was observed during CAB treatment in most patients with macroprolactinoma. CAB was also shown to be effective in patients resistant or poorly responsive to bromocriptine. In view of the limited data on CAB-associated pregnancies and the long half-life of the drug, it is currently recommended that women seeking to became pregnant, once ovulatory cycles have been established, should discontinue CAB therapy 1 month before they intend to conceive. However, no data on negative effects on pregnancy or offspring have been reported. The great efficacy of CAB together with its excellent tolerability makes this drug the current treatment of choice for the majority of patients with hyperprolactinaemic disorders. Very recently, the efficacy of CAB treatment has been reported in patients with acromegaly and clinically non-functioning adenomas with controversial results. CAB was also reported to have some efficacy in patients with Nelson's syndrome and Cushing's disease although these data are available only for limited case reports.

Clinical management of prolactinomas

Prolactinomas are benign, sporadic pituitary tumours that typically present with amenorrhoea and galactorrhoea in women, and hypogonadism and space-occupying effects in men. Hyperprolactinaemic hypogonadism in either sex is associated with reduced bone mineral density, which may be progressive and only partially reversible. For most microprolactinomas, dopamine agonists are the treatment of choice, achieving normoprolactinaemia and restoring gonadal function in 80-90% of cases. Trans-sphenoidal surgery is curative in 60%, but may be complicated by hypopituitarism and is usually reserved for patients with dopamine agonist intolerance or resistance. A subgroup of patients with small tumours, mild symptoms and normal gonadal function may be monitored without specific treatment--the risk of tumour expansion is small. Macroprolactinomas should be treated medically, dopamine agonists controlling prolactin secretion and achieving significant tumour shrinkage in 80% of cases, whereas surgery is curative in only a quarter. Cabergoline is the dopamine agonist of choice in most situations, being better tolerated and more effective than bromocriptine. Quinagolide is an effective alternative. Dopamine agonist withdrawal or dose reduction should be considered after 2-5 years therapy. Oestrogens may be used with caution in women with prolactinomas.

Cabergoline in the treatment of hyperprolactinemia: a study in 455 patients

Cabergoline is a new long-acting dopamine agonist that is very effective and well tolerated in patients with pathological hyperprolactinemia. The aim of this study was to examine, in a very large number of hyperprolactinemic patients, the ability to normalize PRL levels with cabergoline, to determine the effective dose and tolerance, and to assess the effect on clinical symptoms, tumor shrinkage, and visual field abnormalities. We also evaluated the effects of cabergoline in a large subgroup of patients with bromocriptine intolerance or -resistance. We retrospectively reviewed the files of 455 patients (102 males and 353 females) with pathological hyperprolactinemia treated with cabergoline in 9 Belgian centers. Among these patients, 41% had a microadenoma; 42%, a macroadenoma; 16%, idiopathic hyperprolactinemia; and 1%, an empty sella. The median pretreatment serum PRL level was 124 microg/L (range, 16-26,250 microg/L). A subgroup of 292 patients had previously been treated with bromocriptine, of which 140 showed bromocriptine intolerance and 58 showed bromocriptine resistance. Treatment with cabergoline normalized serum PRL levels in 86% of all patients: in 92% of 244 patients with idiopathic hyperprolactinemia or a microprolactinoma and in 77% of 181 macroadenomas. Pretreatment visual field abnormalities normalized in 70% of patients, and tumor shrinkage was seen in 67% of cases. Side effects were noted in 13% of patients, but only 3.9% discontinued therapy because of side effects. The median dose of cabergoline at the start of therapy was 1.0 mg/week but could be reduced to 0.5 mg/week once control was achieved. Patients with a macroprolactinoma needed a higher median cabergoline dose, compared with those with idiopathic hyperprolactinemia or a microprolactinoma: 1.0 mg/week vs. 0.5 mg/week, although a large overlap existed between these groups. Twenty-seven women treated with cabergoline became pregnant, and 25 delivered a healthy child. One patient had an intended abortion and another a miscarriage. In the patients with bromocriptine intolerance, normalization of PRL was reached in 84% of cases, whereas in the bromocriptine-resistant patients, PRL could be normalized in 70%. We confirmed, in a large-scale retrospective study, the high efficacy and tolerability of cabergoline in the treatment of pathological hyperprolactinemia, leaving few patients with unacceptable side effects or inadequate clinical response. Patients with idiopathic hyperprolactinemia or a microprolactinoma, on average, needed only half the dose of cabergoline as those with macroprolactinomas and have a higher chance of obtaining PRL normalization. Cabergoline also normalized PRL in the majority of patients with known bromocriptine intolerance or -resistance. Once PRL secretion was adequately controlled, the dose of cabergoline could often be significantly decreased, which further reduced costs of therapy.

New medical treatment for acromegaly

The available somatostatin analogs for subcutaneous administration lower growth hormone (GH) levels in more than 90% of patients and Insulin-like growth factor-I (IGF-I) levels in up to 60%. They are also capable of reducing tumor size in up to 50%. Recently long-acting somatostatin analogs were introduced. The use of these application forms can result in normalization of IGF-1 in 60% of patients after 1 year and in 75% after 3 years. The development of selective analogs for the somatostatin receptor subtype-5 potentially will enhance the potency and the spectrum of the medical treatment of acromegaly with somatostatin analogs. The new generation of dopaminergic drugs also form a potentially effective and well tolerated therapy that should be considered in the management of those acromegalic patients, which have relative low serum IGF-I concentrations, along with high serum prolactine levels. Finally, growth hormone receptor (GHR) antagonists are under development for the use in humans. Preliminary results look promising, when biochemical parameters are concerned. Interim analysis of a phase 3 study with B2036-PEG in 38 patients does show that normalization of IGF-I concentrations is reached in at least 92% of the treated patients.

Cabergoline: a first-choice treatment in patients with previously untreated prolactin-secreting pituitary adenoma

Cabergoline (CAB) treatment is an effective, safe and well tolerated approach for hyperprolactinemia. We investigated the efficacy of 24-month treatment with CAB in 37 patients with previously untreated PRL-secreting pituitary adenoma and evaluated the hormonal and neuroradiological changes after the discontinuation of long-term therapy. Eleven patients with macroprolactinoma (1M/10F) and 26 with microprolactinoma (4M/22F) started treatment taking 0.25 mg CAB twice a week for 4 weeks. The dose was increased stepwise in 0.5 mg increments until reaching lowest maximally effective and tolerated dose. CAB was withdrawn before the end of the study in 6 women who became pregnant and in one patient who showed a slight increase of the macroadenoma at MRI. During treatment, PRL levels decreased significantly in macro (11.1+/-1.1 vs 407.8+/-98.3 microg/l, p<0.001) and microprolactinomas (11.1+/-1.6 vs 193.8+/-23.4 microg/l, p<0.05) and normalized in all macro and in 23/26 microprolactinomas. In 3 cases PRL levels decreased but did not normalize because the appearance of side effects, such as nausea or hypotension, prevented the increase of the dose of CAB. The effective dose of drug correlated significantly with basal serum PRL levels (p<0.05) and with the pituitary tumor size (p<0.05). A significant decrease of the mean adenoma size was evident for macro (6.9+/-1.8 vs 16.0+/-1.8 mm, p<0.001) and microprolactinomas (3.0+/-0.5 vs 6.5+/-0.4 mm, p<0.001) at MRI. The tumor disappeared in 4 macroadenomas and in 11 microadenomas after 12 months of treatment. CAB withdrawal was followed by serum PRL increase in 13 cases after 3 months, in 6 after 6 months, in 2 after 9 months, and in one patient at the 12th month. Five patients showed normoprolactinemia with negative MRI after one year. Regular menses were restored in 7/10 macroprolactinomas and in all oligo-amenorrhoic patients with microadenoma; serum testosterone levels normalized in 2/3 hypogonadic men. Five out of 6 women become pregnant and had uneventful pregnancies which resulted in deliveries of normal babies. In conclusion, this study confirms the effectiveness and safety of CAB for patients with PRL-secreting pituitary adenoma and suggests that it can be considered a first choice treatment.

Long-term treatment with cabergoline, a new long-lasting ergoline derivate, in idiopathic or tumorous hyperprolactinaemia and outcome of drug-induced pregnancy

Cabergoline (CAB), a new long-acting ergoline derivative, was shown to be very effective in reducing PRL levels in normal volunteers and in hyperprolactinemic patients. We evaluated the hormonal changes after discontinuation of long-term therapy with CAB as well as the safety of drug exposure during pregnancy both for mothers and babies. We therefore studied 48 patients (47 females and one male) with pathological hyperprolactinaemia (mean +/- SE, 117.2 +/- 15.2: median 73.2 micrograms/l), treated for 1-82 months (mean +/- SE, 28.3 +/- 3; median 18). After long-term treatment, CAB was withdrawn in 11 patients and PRL levels were persistently normal for almost 15 days and significantly lower (p < 0.05) than basal at 30, 45, 60, 90, 120 days. Three patients had normal PRL levels still at 45 days after treatment discontinuation. Nine patients became pregnant after 1-37 months (mean 12.4) of therapy. In two patients the pregnancy was interrupted spontaneously in one case and voluntarily in the other. In all but one patients after delivery or three-month breast feeding, PRL levels trended towards reduction. In two cases (one with microadenoma and one with idiopathic hyperprolactinaemia) PRL remained in the normal levels for 1-3 years after delivery. In conclusion CAB is able to inhibit plasma PRL levels for long time (up to 120 days) after withdrawal in patients with pathological hyperprolactinaemia treated with long-term therapy.

Pituitary tumours in the elderly

Pituitary tumours in the elderly are a neglected topic in the literature of endocrinology and gerontology. Data from autopsy studies in the elderly show that the commonest tumours are microadenomas, which are either immunocytochemically negative or stain for prolactin. Prolactin-secreting pituitary tumours, however, appear rarely in clinical series of patients in this age group and non-functioning adenomas are the commonest tumour seen, although pituitary metastasis and craniopharyngiomas also occur. Diagnosis can be difficult, but the commonest presentation is visual field loss. Hypopituitarism may be diagnosed late and incidental radiological diagnosis is not uncommon. There are few data which specifically answer the question, but there is a suggestion that the syndromes associated with hormonal hypersecretion may be milder in this age group. Conventional treatment with drugs, surgery and radiotherapy should be decided on an individual basis as these therapies appear to be well tolerated and beneficial in selected patients.

Pregnancy outcome after treatment with the ergot derivative, cabergoline

The goal of this article is to assess the reproductive safety of cabergoline, a new ergot derivative proposed in hyperprolactinemic disorders. Investigated in different animal species, the drug showed no teratogenic or embryotoxic effects on rabbits. Considering the dose envisaged for humans, large safety margins exist. Our sample consists of 226 pregnancies occuring in 205 women. Follow-up is available for 204. There were 24 miscarriages and three abortions induced because of major malformations (one Down syndrome in a 42-year-old woman, one limb-body wall complex, one hydrocephalus). Two of the 148 single liveborn infants had significant malformations: one megaureter, one scaphocephaly. This series shows no increase in miscarriage rate, a distribution of birthweights and sex ratio within the expected range, and no increased rate of congenital malformations. Follow-up of babies, limited to 107 cases, thus far indicates normal physical and mental development.

Quinagolide efficacy and tolerability in hyperprolactinaemic patients who are resistant to or intolerant of bromocriptine

OBJECTIVE

To audit the efficacy of quinagolide (CV205-502, Norprolac, Sandoz) in lowering prolactin, and its tolerability, in patients with bromocriptine resistance (BCR) or bromocriptine intolerance (BCI), in view of the paucity of results published in patients specifically with BCR or BCI, by collating results in our own patients with the reports in the literature.

DESIGN

Open prospective, uncontrolled administration of quinagolide in patients with BCR (defined for this report as failure to attain normal prolactin levels after 4 months of bromocriptine at maximum tolerated doses), or BCI (defined as a patient request to cease bromocriptine treatment because of side-effects at doses that were required, or failed, to normalize PRL levels).

MEASUREMENTS

Prolactin levels, menses or pregnancy, and side-effects.

PATIENTS

Six with BCR, and six with BCI (microprolactinoma in 7, macroprolactinoma in 5), treated with quinagolide 75 micrograms nightly increasing incrementally to a maximum of 450 micrograms. One patient who had taken part in a multicentre study of quinagolide in macroprolactinomas had BCI, and 11 further patients in the endocrine clinic who had BCR or BCI were offered quinagolide therapy under named-patient compassionate arrangements.

RESULTS

Normal prolactin in 4/5 with BCR (3/6 with side-effects, none of them quinagolide intolerant), and normal prolactin in 2/6 with BCI (4/6 with side-effects, two of them quinagolide intolerant).

CONCLUSIONS

Results in our 12 patients are broadly in line with those in 51 patients with bromocriptine resistance and 39 with bromocriptine intolerance extracted from various published reports, which together suggest that prolactin can be normalized in 16% of patients with bromocriptine resistance by quinagolide in doses of 225 micrograms or less, and in a further 20% by higher doses up to 600 micrograms. In bromocriptine intolerance, prolactin was normalized by quinagolide in doses of 225 micrograms or less in 58% of published cases and in 3 more patients by higher doses up to 1050 micrograms. About half the patients with bromocriptine resistance or bromocriptine intolerance who are treated with quinagolide experience side-effects, and around 7% are quinagolide intolerant. Doses need not exceed 225 micrograms, until failure to respond at this dose level is demonstrated.