Pharmacology of the nervous system Flashcards
What is Pharmocology?
A chemical substance that interacts with a specific target within a biological system to produce a physiologic effect?
What are 3 questions you should consider when using a drug?
where is the effect produced? What is the target for the drug? What is the response produced after the interaction with this target?
What are the 4 main targets of drug targets?
Receptors Enzymes Transport Proteins Ion Channels (occasionally this is not the case)
What effects do drugs have on targets?
They either: -Enhance activation (stimulate effect) -Prevent activation (block target)
Why would a drug have a n effect on a target?
The drug must show HIGH DEGREE OF SELECTIVITY for a particular drug target
Why might the selectivity be more important for drugs then endogenous compounds like dopamine?
3 neurotransmitters that are similar structurally may all be able to interact with the same drug target e.g. Dopamine, Noradrenaline and Serotonin can all interact with dapamine receptor even if dopamine is the best fit. However nerves release neurotransmitters DIRECTLY onto target so this isn’t a huge worry. However man made drugs are administered in such a way that the drug enters you blood stream and can circulate around the whole body so it is important that these drugs are highly specific so that they don’t act on many different drug targets instead of the one its meant to act on.
What is a side affect and adverse affect?
side effect- effect of drug secondary to the intended effect Adverse effect- a side effect that is negative
What happens when you give different doses of Pramipexole?
This is a dopamine receptor agonist so is used to treat Parkinsons If you give a low dosage it is enough to cause dopamine like responses and not bind the serotonin receptors as well. But if you give a lot it’ll start interacting with serotonin receptor and you’ll see these side affects e.g hallucinations If you increase the dose further it’ll start acting on noradrenaline receptors which will result in hypertension (low blood pressure) side affects and therefore the brain isn’t receiving enough blood These shows that selectivity and dose is related as in this case higher dose = less selectivity
What are off target effects?
Side effects that are due to drugs binding to there target receptors but in the wrong part of the body
Where are dopamine receptors in the body? How does this effect the use of Pramipexole?
eyes vessles heart adrenals kidney gut This means even though the drug is meant to bind to targets in the brain to control Parkinson’s, it will get else where and bind to same target in different body parts to cause side effects.
Summarise the 3 reasons why side effects occur due to drug action?
1- drugs effect other targets in same of different tissue 2- drugs effect same target in different tissues 3-dependent on the dosage of drug administered
What are the safest drugs?
Those where there is a large difference between the dose required to induce the desired effect and the dose required to induce side effects
