Thomas A. Ban: Psychopharmacology. Baltimore: Williams and Wilkins; 1969

Leon S. Morra’s Extracts 6
Part One, Chapter Two: Animal Pharmacology

Chapter Two is divided into two sections: A. Pharmacodynamics and B. Toxicity

“Animal pharmacology is the scientific study of the effect of drugs on the animal organism… A preliminary step in the animal pharmacological investigation is to establish an effective dosage range for the new substance."

“Experiments to establish the effective dose rang are carried out in conscious (non-anesthetized), non-restricted (non-paralyzed) animals… At the same time, dose-response curves are obtained by administering single doses of the drug in increasing amounts."

“It is most important to recognize the smallest dose which produces any detectable effect and the LD50, i.e., the dosage which produces a particular effect in 50% of the animals… It is also essential to detect the smallest amount of the drug which produces an irreversible impairment or a lethal effect and establish the LD50, i.e., the dose which kills 50% of the animals…"

“At this point the therapeutic index, i.e., the ratio between the lethal dose (LD50) and the effective dose (ED50), is calculated. A high therapeutic index, i.e., a wide discrepancy between the LD50 and the ED50, is one of the prerequisites of further exploratory work with the substance.”


León S. Morra

March 16, 2017