Pharmacology Flashcards
Symptoms of parasympathetic activity?
“DUMBBELSS”
D: Diarrhea U: Urination M: Miosis B: Bronchospasm B: Bradycardia E: Excitation of skeletal muscle & CNS L: Lacrimation S: Sweating (fever) S: Salivation
Organophosphate poisoning (due to Cholinesterase inhibitors)
Atropine (competitive inhibitor of ACh)
Pralidoxime (regenerates AChE)
Symptoms of inhibiting Parasympathetic activity
Dry as a bone - decreased secretions and salivation
Hot as a hare - increased temp
Red as a beet - peripheral vasodilation
Blind as a bat - mydriasis, cycloplegia
Mad as a hatter - agitation, delirium
Bloated as a toad - constipation, urinary retention
What is Km
substrate concentration that gets reaction to half of Vmax
Amount of substrate required to get enzyme to half the maximum velocity
lower Km
in Michaelis-Menten plot
higher affinity of enzyme for substrate
slope of graph will be steeper / get to Vmax much faster
y-intercept in Lineweaver-Burk plot
1/Vmax
x-intercept in Lineweaver-Burk plot
1/-Km
slope in Lineweaver-Burk plot
Km/Vmax
More enzyme in Lineweaver-Burk plot will do what to the y-intercept?
y-intercept will be lower because Vmax will be higher
More enzyme in Lineweaver-Burk plot will do what to the x-intercept?
nothing, only changes y-intercept
How to overcome competitive inhibitor?
Add more substrate and dilute it out! Thus Vmax does not change because it will eventually reach maximum.
Noncompetitive inhibitors do what to Vmax?
Decreases Vmax, thus changes y-intercept.
HOWEVER, does NOT change Km
Volume of Distribution (Vd)
Vd = amount of drug given in IV form / plasma drug concentration
Clearance (CL)
CL = rate of drug elimination/ plasma drug concentration
CL = 0.7 x Vd / half-life of drug
CL = K (elimination constant) x Vd
Loading Dose (LD)
LD = Css (steady state conc -or- target conc) x Vd
