Pharmacodynamics / Pharmacokinetics (1) Flashcards
Hyperreactive definition
low dose produces a pharmacologic effect
Hypersensitive definition
Allergic type reactions
Hyporeactive definition
Need a larger dose to get pharmacologic effect
idiosyncracy definition
rare / unpredictable reaction from a drug administration, unrelated to dose or normal mechanism
- e.g. child takes Benadryl = excitation response (from underdeveloped neurological system)
Proteins have 4 major levels of structure: Primary:
determined by the sequence of amino acids
Proteins have 4 major levels of structure: Secondary:
Determined by interaction of negative and positively charged atoms (alpha helix, beta pleated sheet)
Proteins have 4 major levels of structure: Tertiary
Determined by ionic and covalent bods, gives 3D structure
Proteins have 4 major levels of structure: Quaternary:
Determined by binding of two or more independent proteins
Binding site on receptor is affected by (in order strongest to weakest)
(Stronger) Covalent > Ionic > hydrogen > VanderWaals forces (weaker)
binding is rarely caused by just one interaction
Covalent
Shares electrons - often not reversible
Phosphorylation
Turns protein on or off - Very important in many receptor systems
Pharmacodynamics
What the Drug Does to the body - study of the intrinsic sensitivity or responsiveness of receptors to a drug and the mechanisms by which these effects occur
Pharmacokinetics
What the body does to a drug (ADME)
ADME
Absorption, distribution, metabolism, excretion
Pharmacodynamics important factors:
hydrophilic / hydrophobic
Ionization state (pKa)
Conformation and stereochemistry
Ion channel binding, spanning the plasma membrane have what gates?
Ligand gated (hypnosis, benzos, muscle relaxants, ketamine)
Voltage gated (local anesthetics)
Heptahelical receptors:
Spain the plasma membrane coupled to intracellular G proteins (2nd messenger, GPCRs) - most common in humans
Binding to extracellular side of transmembrane receptor acts on intracellular enzyme (receptor linked enzymes) eg =
GH, Insulin, PDE
These drugs diffuse through the plasma membrane
lipophilic drugs
Extracellular enzymes:
target is outside the plasma membrane
Nicotinic Acetylcholine receptor is comprised of these 5 subunits
2 x Alpha (when both alpha subunits are bound the channel opens)
Beta
Gamma
Delta
What is bound to the alpha subunit when it is attached to the GPCR?
GDP (think docked)
When a signaling molecule joins with the GPCR, a conformational change occurs and _______ replaces _______ on the alpha subunit. As a result the subunits (alpha, beta, gamma) dissociate into two parts.
GTP replaces GDP (GTP think Transformational change, transfer, or transport)
2nd messengers include:
Calcium, cAMP, cGMP, inositol