Effect of fluphenazine on pituitary function in man

Area of Science:

• Endocrinology
• Neuropharmacology
• Alcoholism Research

Background:

• Alcoholism can affect endocrine function.
• Insulin-induced hypoglycemia is a standard test for growth hormone (hGH) and prolactin (hPRL) release.
• Fluphenazine is a typical antipsychotic with potential endocrine side effects.

Purpose of the Study:

• To investigate the effect of fluphenazine (Modecate) on hGH and hPRL response to hypoglycemia in alcoholics.
• To assess changes in hypothalamic-pituitary function after fluphenazine administration.

Main Methods:

• Six alcohol-dependent patients were studied before and after a single intramuscular injection of fluphenazine (12.5 mg).
• Insulin-induced hypoglycemia (0.1 u/kg soluble insulin) was administered intravenously.
• Blood samples were collected at intervals to measure hGH and hPRL levels.

Main Results:

• An adequate hGH response to hypoglycemia was observed before fluphenazine treatment.
• Fluphenazine treatment significantly impaired the hGH response to hypoglycemia.
• Basal hPRL concentrations increased significantly post-treatment.
• Increased hPRL concentrations in response to hypoglycemia were noted after fluphenazine administration.

Conclusions:

• A single 12.5 mg dose of fluphenazine (Modecate) markedly affects hypothalamic-pituitary mechanisms.
• Fluphenazine alters the regulation of hGH and hPRL release in response to hypoglycemia.
• These findings highlight the neuroendocrine impact of fluphenazine in individuals with a history of alcoholism.