| What is pharmacokinetics? | ADME
Any successful drug should be able to cross barriers (as they are considered by the body as xenobiotic foreigners)
And to be eliminated they should be metabolized by liver and then excreted
When distributed they are found in the blood either free or bound (these proportions are in equivalence)
The bound molecules serve as reservoir and free ones are what get diffused |
| What are the main mechanisms of transport? | Filtration (paracellular diffusion through aqueous pores where small molecules and water only go)
Passive diffusion (most drugs by gradient and Fick's law, transcellular diffusion)
Active diffusion |
| What is the Fick's law governing passive diffusion rate? | Rate= Diffusion constant * Surface area * Partition constatnt * gradient (Concent high - low) / thickness |
| What is the partiton constant? | It describes how lipophilis is the molecule being studied whether it diffuses or not.
logP (could be negative) |
| Why should we know ionization state of drugs? | Since ionized drugs cannot pass by passive diffusion, so we should study the pH of the drug and thus knowing where will it be absorbed and where not.
To compensate we may alkalinize the drug if it where acidic either by swallowing or by urine or by rectum.
We may also use an antedote to stop toxin and inhibit it |
