Pharmacology of the nervous system Flashcards
What is pharmacology?
A chemical substance that interacts with a specific target within a biological system to produce a physiological effect
What is the response, effect and target of heroine?
Response: Euphoria, analgesia, cough suppression
Effect: analgesia produced in periaqueductal grey region, euphoria produced in ventral tegmental area, cough suppression in solitary nucleus
Target: opioid receptor
Where can side effects be produced?
On other target cells in same tissue or other tissues
On same target in other tissues
What factors make the ‘safest’ drug?
Large difference between dose required go induce desired effect and dose required to induce side effect/adverse effect
What are the 4 main classes of drug target?
Receptors
Enzymes
Transport proteins
Ion channels
What are the 4 most commonly prescribed drugs?
Atorvastatin
Amlodipine
Salbutamol
Citalopram
What does atorvastatin do and target?
Lowers cholesterol
Target is enzyme- blocks HMG Coa reductase
What does amlodipine do and target?
Treats hypertension
Target is ion channel- blocks calcium channel
What does salbutamol do and target?
In inhalers
Target is a receptor- activates beta-2-receptor
What does citalopram do and target?
Anti-depressant drug
Target is a transport protein- blocks serotonin reuptake protein
What is the importance of drug selectivity?
To be an effective drug it must show a high degree of selectivity for a particular drug target
e.g. dopamine, serotonin and noradrenalin all look similar so can fit into the same sort of ‘lock’
Why is selectivity more important for drugs than endogenous compounds like dopamine?
NTs are specifically delivered to their drug target wheat drugs are typically administered orally and travel via bloodstream so can be distributed to any tissue
What is a side effect?
An effect produced by a drug that is secondary to the intended effect
Has a negative health impact
What is pramipexole and what’s the importance of its dose administration?
Its a dopamine receptor agonist
Used to treat Parkinson’s disease
At low dose has therapeutic effect however as you increase dose you may see serotenergic effects- pramipexole is close in structure to serotonin so may bind with serotonin receptor and produce side effect
If you continue to increase does you may get more side effects as pramipexole also looks like noradrenalin so may bind to its receptors
This is an example of off-target effects
Whats the relationship between dose and selectivity?
As dose increases, selectivity decreases
