Pharmacology Flashcards
what does the term pharmokinetics mean?
what the body does to the drug;
- absorption
- distribution
- metabolism
- excretion
what does the term pharmodynamics mean?
what the drug does to the body; its biological effect on the body
what is a drug?
a substance which affects the biochemistry/physiology of the body in some way
what does biochemistry mean
the chemical and physio-chemical processes and substances occuring within the body
polypharmacy?
the use of multiple (more than 1) medications
what does pharmacology mean?
the branch of medicine concerned with the uses, effects, modes, and actions of drugs
which drugs do not target human cells?
antimicrobials
what are receptors in relation to drugs?
- mainly cell surface proteins which have a definite structure and that bind the drug in a lock & key type arrangement
- receptors act as the receptionist; binding with the drug
- receptors must then however activate/deactivate a messaging system in the cell to exert the drugs effect
what are agonists? & examples
- drugs that bind to the receptor and activate it
- adrenaline binds to adrenergic receptors the stimulate them
- insulin binds to & activates insulin receptors
what are antagonists? & examples
- a substance which blocks the effect of another substance
- drugs that bind to and block receptors, stopping the agonist from accessing the receptor
- beta blockers binding and blocking adrenergic receptors, blocking the sympathetic effects of adrenaline and noradrenaline
what is transduction?
whatever mechanism the receptor has to affect cell behaviour
what is an enzyme
biological catalysts which speed up biochemical reactions in living cells
where are enzymes found
- inside cells
- outside cells
what relation does ibuprofen have on certain enzymes?
iboprufen blocks the enzyme which produces prostoglandins; which are important inflammmatory mediators
whar are carriers and pumps?
- proteins in cell mebranes which control what enters & exists the cell
- carriers facilitate passage through a membrane without requiering energy
- pumps facilitate passage through a membrane but requiere energy to do so; active transporters
Adverse reactions (ABCDE) ; common side effects
augmented (or increased); where drug levels are too high and desired effect is excessive
bizzare (or unpredictable); not dose related such as unknown allergy
chronic; associated with long term use of the drug; e.g., irritation of the GI lining, perhaps stomach ulcers
delayed; an antibiotic rash which appears days after the antibiotic has been stopped
end of treatment; such as withdrawals
ADME
- Aborsbed; across the gut wall & into bloodstream
- distributed; around the body to target tissue(s)
- metabolised; to allow drug to be excreted
- excreted; ridded of by the body, e.g., in the urine
why may it be reccomended to take a drug with a glass of cold water?
cold water accelerates gastric emptying which means passage & absorption of drug is faster; if this is desired
why may it be reccomended medication is taken at night time?
some drugs have a sedative effect
why may it be reccomended to take medication with/without food
with- slower absoprtion rate is desired and because some medications such as anti-inflammatories can irriate the stomach’s lining
without- food in the stomach, especially starchy/protein rich food requiere’s more work from the stomach to digest resulting in slower passage & absorption of the drug than desired
does absorption of a drug occur in the stomach?
- no
- the stomach is not designed for absoprtion but is a reservoir
- drug must be passed into duodenum from stomach for absorption to occur
what factors can delay drug absorption?
- food in stomach
- pain/distress/shock can trigger the sympathetic NS, shutting dowen the GI tract, directing blood away from here and towards muscles
how do most drugs pass through cell membranes?
via difussion
what is a loading dose?
an initial higher dose of a drug at the beginning of of a course of treatment before lowering it to lower maintenance dose. this is most useful for drugs that are excreted from the body relatively slowely.
