Basic Pharm Flashcards
Michaelis-Menten kinetics basics
[S] on X axis and V on Y axis
What is Km
it’s the substrate concentration needed to get 1/2Vmax
Vmax is directly proportional to
Directly proportional to the enzyme concentration
Lineweaver-Burk plot basics
1/[S] on the X axis and 1/[V] on the Y axis.
1/Vmax is the Y intercept so doesn’t change for competitive inhibitors.
Smaller Km makes the X intercept more negative
The shallower the slope, the higher V
What drugs have zero-order elimination?
Phenytoin, Ethanol, Aspirin [PEA is shaped like a 0]
What drugs are weak acids and how to eliminate quicker
Phenobarb, MTX, aspirin.
Trap in urine with bicarb to ionize
What drug is a weak base and how to eliminate quicker
Amphetamines: give ammonium chloride to ionize and trap in urine
Phase I drug metabolism
Cytochrome P-450 redox and hydrolysis for slightly polar metabolites.
Phase II drug metabolism
Conjugation (GAS: glucuronidation, acetylation, sulfation): makes very polar inactive metabolites that are renally excreted
What phase of drug metabolism do Geriatric patients lose first?
Phase I, they have intact Phase II
flumazenil MOA
competitive antagonist at GABA-R
ketamine MOA
noncompetitive antagonist on NMDA-R
phenoxybenzamine MOA
irreversible competitive antagonist on alpha receptors
buprenorphine MOA
partial agonist at opioid mu-receptors
Therapeutic index
TD50/ED50
What NT and receptor for all preganglionic nerve
Every preganglionic neuron in the spinal cord releases ACh onto Nicotinic receptors.
Innervation of sweat glands
Sympathetic ACh on M receptors
Innervation of renal vasculature, smooth muscle
D on D1 receptors
Innervation of parasympathetic cardiac and smooth muscle, gland cells, and nerve terminals
ACh on M receptors
Sympathetic is NE on alpha, beta receptors
Botulinum toxin basic MOA
prevents release of NT at all cholinergic terminals
Difference between nicotinic and muscarinic ACh receptors
N: ligand-gated Na/K channels (Nm on NMJs, Nn on autonomic ganglia)
M: G-protein coupled receptors (M1-M5)
