FoM:L1 - What is a Drug? Flashcards
What is a drug?
An active substance with a direct effect in the diagnosis, cure, mitigation, treatment or prevention of disease
What is a placebo?
An inactive substance administered as though it is a drug, but which has no therapeutic effect
What are the important attributes of drugs that need to be quantified?
- purity
- potency
- efficacy
- variability
- selectivity
- safety
- bioavailability
- cost
What is variability?
what proportion of patients have the desired response
How does a drug bind to a receptor?
reversibly
How do drugs interact with targets?
makes transient contact with a target
What is a agonist?
- endogenous substance or drug acting at a receptor
- activates receptor signalling to produce a response
What is an agonists affinity?
the extent to which a drug binds to a receptor at a given concentration
What is intrinsic activity?
efficacy
- the ability of a drug to illicit a pharmacological effect
What shape is produced when plotting a dose logarithmically?
sigmoid
What is the effective dose (EC50)?
50% of the response
What is therapeutic index?
Therapeutic dose / effective dose
What does a wide therapeutic index mean?
few people taking a therapeutic dose will experience toxic effects
What is pharmacovigilance?
Why would a drug be considered specific?
affinity and intrinsic activity for specific receptors
HOWEVER, may have low affinity for other receptors which leads to an unwanted response
