Use of Endocrine Drugs

The general ways in which pharmacologic agents can be used to alter endocrine activity are as follows. 

Replacement Therapy. If the endogenous production of a hormone is deficient or absent, therapeutic administration of the hormone can be used to restore normal endocrine function.30 35 The exogenous hormone can be obtained from natural sources, such as extracts from animal tissues, or from chemical synthesis. In addition, new recombinant DNA techniques are being used to produce hormones from cell cultures, and these techniques have shown great promise in being able to generate hormones like human insulin. 

Hormone substitution is sometimes referred to as simple replacement therapy. However, the use of exogenous hormones to replace normal endocrine function can be a complicated task. Problems such as regulation of optimal dosage, the interaction of the exogenous drug with other endogenous hormone systems, and drug-induced side effects are frequendy encountered. 

Diagnosis of Endocrine Disorders. Hormones or their antagonists can be administered to determine the presence of excess endocrine function or endocrine hypofunction. For example, hormones or their synthetic analogs can be administered that either increase or decrease pituitary secretion to determine if pituitary function is normal. Likewise, antagonists to specific hormones can be administered to see if symptoms are caused by excessive hormone production. Specific examples of how hormones are used to diagnose endocrine abnormalities are presented in subsequent chapters. 

Treatment of Excessive Endocrine Function. Hyperactive or inappropriate endocrine function is often 

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