Clomiphene Citrate for Treatment of Acromegaly

To assess the impact of clomiphene citrate on serum insulin like growth factor 1 and testosterone levels in male acromegalic patients not controlled by surgery, radiotherapy and/or medical treatments (somatostatin analogues, dopamine agonists and/or growth hormone receptor antagonist)

Acromegaly, a disease caused by a growth hormone secreting pituitary adenoma, results in reduced life span. Despite the many modalities available to treat this disease,as surgery, medical treatment and radiotherapy, uncontrolled disease persists in a significant portion of patients Oral estrogens, alone or in combination with somatostatin receptor analogues, have been shown to control acromegaly in women. Selective estrogen receptor modulators (SERMs) resulted in similar effects in both genders. Clomiphene citrate, a SERM that increases luteinizing hormone and follicle stimulating hormone secretion, improves hypogonadism and fertility outcomes. The aim of this study is to assess the impact of clomiphene citrate on serum insulin like growth factor 1 and testosterone levels in male acromegalic patients not controlled by surgery, radiotherapy and/or medical treatment. In this prospective, open label, single center trial, sixteen male patients were studied. Clomiphene citrate (50 mg/day) was added to previous medical treatment for 3 months and hormonal assessment was performed prior to and during the intervention. Hormones included: growth hormone, insulin like growth factor, total testosterone, follicle stimulating hormone, luteinizing hormone and prostate-specific antigen.

The objective is to compare the change of IGF-1 value assessed in the beginning of the study (day 0), with the value obtained after three months of use of clomiphene citrate (day 90).

The objective is to compare the change of testosterone value assessed in the beginning of the study (day 0), with the value obtained after three months of use of clomiphene citrate (day 90).

The objective is to compare the change of PSA value assessed in the beginning of the study (day 0), with the value obtained after three months of use of clomiphene citrate (day 90).

Inclusion Criteria: patients with active acromegaly on regular use of a stable dose of Octreotide-LAR and/or cabergoline for at least one year, Insulin like growth factor 1 above the reference range during the last year of follow-up and testosterone levels within or below the third inferior tertile of normality. Exclusion Criteria: radiotherapy in the last 10 years, previous venous embolism (including family members), previous prostatic cancer or symptomatic benign hypertrophy, triglyceride levels above 400 mg/dL, renal failure defined by estimative of renal filtration below 30 ml/min, liver disease defined by hepatic enzymes 3 times above normal limit, active oncologic disease in the last 10 years and previous cardiac or cerebrovascular disease.

Unit of Neuroendocrinology, Discipline of Endocrinology, Department of Internal Medicine Clinical Hospital of the University of São Paulo Medical School, São Paulo, Brazil