20 - More Pharmacology Flashcards
Pharmacokinetics
Effect of the body on the drug
Pharmacodynamics
Effect of the drug on the body
Effect of the body on the drug
Pharmacokinetics
Effect of the drug on the body
Pharmacodynamics
Digitalis
Inhibits Na+/K+ ATPase.
This increases Ca2+ entry into cardiac muscle which increases cardiac stimulation.
Too much leads to cardiac arrhythmias.
Why is the therapeutic window small for digitalis?
The desired effect and adverse effect are the same.
Prenalterol
Beta1 selective agonist
Example of a beta1 and 2 agonist
Isoprenaline
Example of a beta1 agonist
Prenalterol
Can affinity be inferred from dose-response curve?
No.
What can be inferred from a dose-response curve?
Potency of a drug, maximum effect of a drug.
Isoprenaline vs prenalterol on a dose-response curve for tachycardia
Isoprenaline is more portent, has a greater maximum effect (100% vs ~70%)
Characterisation of different agonist types
Maximum possible effect - full agonist
Less-than -maximum possible effect - partial agonist
Beta2 adrenoceptor partial agonists
Salbutamol
Prenalterol
Example of an opiate receptor partial agonist
Buprenorphine
Isoprenaline and prenalterol have similar affinities for beta1 adrenoceptors. Why is the potency so different?
Isoprenaline has a greater innate pharmacological efficacy
Measure of potency
EC50 (effective concentration of 50% response).
The lower the EC50, the more potent the drug.
Pharmacological efficacy
The ability of a drug to stimulate a receptor
Clinical efficacy
The strength of beneficial effect of a drug
Inotropic
Affecting force of muscle contractions
Name for when a drug can have maximum effect without binding to all possible receptors
Spare receptors
