These are pharmacology basics you search, you'll need books. Here are papers for each glossary you need:
1- the therapeutic index (TI) is the interval separating the therapeutic doses from the toxic . ones. It is calculated as the ratio between the lethal dose 50 (LC50) and the effective dose 50 (EC50) TI = LC50/ EC50.
3- the pharmacokinetics is the study of the evolution of concentrations of a drug in the blood or other body fluids (urine, cerebrospinal fluid ...) through time. in other words, it is the study of the effects of the body on the drug. It consists in 4 phases (absorption, distribution, metabolism and excretion). We determine pharmacokinetic (PK) parameters for each phase.
4- Diuretics are drugs that can increase the amount of water and sodium that is excreted in the urine. There are several classes with a different mechanism of action. (Loop diuretics, Thiazide diuretics, Carbonic Anhydrase Inhibitors, Potassium-sparing diuretics and Osmotic diuretics), you'll find more details in: