ppt 1 Flashcards
•the practice of medicinal chemistry that is devoted to the discovery and development of new drugs
Organic Medicinal Chemistry
•an agent intended for use in the diagnosis, mitigation, treatment, cure, or prevention of disease in humans or in other animals
DRUG
•a substance to which a drug needs to interact with to elicit a pharmacological response
•90% proteins, some are nucleic acids and lipids
RECEPTOR
•ability of drug to bind to the receptor
AFFINITY
•ability of a drug to exert a pharmacologic action
INTRINSIC ACTIVITY
•Affinity + Intrinsic activity
AGONIST
•Affinity only
ANTAGONIST
•site other than the binding site
ALLOSTERIC SITE
•the transfer of a drug from its site of administration to the systemic circulation (or to the bloodstream)
ABSORPTION
FACTORS THAT INFLUENCE THE ABSORPTION:
•Chemical structure
•Variation in particle size
•Nature of the crystal form (Amorphous > Crystalline)
= 100% crystalline (long-acting)
Ultra-lente
= 70% crystalline, 30% amorphous (intermediate)
Lente insulin
= 100% amorphous (short-acting)
Semi lente
What are the Three Basic Modes of Drug Transport Across a Membrane?
-passive diffusion
-facilitated diffusion
-active transport
•the fraction of administered drug that reaches the systemic circulation in a chemically unchanged form (f)
BIOAVAILABILITY
•the process by which a drug reversibly leaves the bloodstream and enters the interstitium (extracellular fluid) and/or the cells of the tissues
DISTRIBUTION
•serves as a reservoir
•Albumin - binds acidic drugs
•α-1-acid-glycoprotein - binds basic drugs
•may limit access to certain body compartments
•Prolongs drug duration of action
PLASMA PROTEIN BINDING
•converts drugs into polar form, water-soluble products that are readily excretable
•detoxification process but not all the time
METABOLISM
•compounds that are inactive in their native form, but are easily metabolized to the active agent
Ex:
–Enalapril to Enalaprilat
–Chloramphenicol palmitate to Chloramphenicol
–Primidone to Phenobarbital
–Phenacetin to Paracetamol
PRODRUGS
•drugs may be metabolized by hepatic enzymes to inactive chemicals (drug is metabolized prior to absorption)
•only drugs administered orally and rectally undergo first pass metabolism (CYP 450)
•Ex: Nitroglycerin
FIRST PASS EFFECT
what is the main route of excretion of a drug and its metabolite?
kidney
•drugs emptied via the bile duct into the small intestine can be reabsorbed in the intestinal lumen back to systemic circulation
ENTEROHEPATIC RECIRCULATION
