Title 6. DRUG TOXICITY - ACUTE, SUB- ACUTE AND CHRONIC TOXICITY.pdf ✅

PHARMD GURU Page 1 F) DRUG TOXICITY - ACUTE, SUB- ACUTE AND CHRONIC TOXICITY.  A drug should be carefully and ethically evaluated by testing in human beings for safety and efficacy prior to its use in man for therapeutic purposes. Such study in humans is referred to as clinical trial.  Preclinical studies in animals: Before undertaking clinical trials, sufficient data about the drug must be obtained by testing it in animals. Animal studies generate pharmacodynamic, pharmacokinetic and toxicological data of the drug. TOXICITY STUDIES ACUTE TOXICITY STUDIES:  Acute toxicity is carried out in two animal species (one rodent, one non-rodent).  Single, graded doses are administered to small groups of animals using two routes— one that is to be used in human. It is done to determine the general behaviour and median lethal dose (LD50) following exposure to the test drug.  LD50 is the dose required to kill 50% of the animals. It is determined in a 24-hour period after administration of the drug. SUBACUTE TOXICITY STUDIES:  These are done in two species of animals to determine the maximum tolerated dose, identify target organ of toxicity and nature of toxicities.  The test drug is administered daily for a period depending on the duration of treatment in humans.  Animals are examined for general effects (food intake, change in the body weight, etc.), biochemical and haematological parameters are monitored; histological examination is done. GENERAL PHARMACOLOGY