PCOL M1.3 part 2 Flashcards
where the actions attributed
Main site
are effector binding sites within enzymes
Allosteric sites
Act on the particular site in the receptor is the pharmacological response
Neurotransmitter
- has affinity but no pharmacological response which is the contraction [No/zero Efficacy- walang ganung effect] instead it will have RELAXATION [hindi ibig sabihin walang action pag no pharmacological response ibig sabihin lang nun ay iba yung reaction/OPPOSITE yung reaction na mangyayari]
ANTAGONIST
Ex in Agonist sa Beta 1 [anong drug yung nasabi ni maam]
perfectly fits in to the receptor site [has affinity], it gives the pharmacological responsible similar to the neurotransmitter [high efficacy] = CONTRACTION of cardiac muscle
Dobutamine
Initiate cell function producing efficacy of various types
AGONIST
- depends on; affinity and effects
refers to the relative concentration required to produce a given magnitude of the effect.
Konting amount lang nakakaproduce ng mataas na response
POTENCY
- has high efficacy (full activation)
- Promote contraction
Full agonist
(intermediate efficacy) - less activation
Partial agonist
- has zero efficacy.
- bind to receptors without initiating changes.
- It usually inhibits or blocks responses caused by agonists.
- The principle of antagonism is to opposed the agonist
- Promote relaxation
Antagonist
– identify by structural non-specific
CHEMICAL ANTAGONISM
- Neutralization
- Two substances combine in solution so that the effect of the active drug is lost [– due to chemical reaction]
CHEMICAL
Explain what will happen in Neuralization chemical antagonist
Acid in the stomach = high acidity means need nya ng base to neutralized] so need nya ng antacid to neutralized / it is categolized in structural non specific
Explain what will happen in Two substances combine [Dimercaprol chelates heavy metals and thus reduces their toxicity] chemical antagonist
Mechanism involve chelation
1st substance – Dimercaprol
[reduce toxicity]
2nd substance – heavy metals
[lead to toxicity]
ex. Gold, silver, mercury, and lead
[pagpumasok ang heavy metal sa katawan mo mag lead to toxicity, while Dimercaprol reduce the toxicity]
- Antagonist effectively reduces the concentration of the active drug at its site of action
PHARMACOKINETIC antagonism
Explain what happen here Phenobarbital reduces the anticoagulant effect of warfarin by accelerating its metabolism by pharmacokinetics antagonism
Mechanism involve ADME
Phenobarbital – can opposed the anticoagulant [enzyme inducer – nagaccelerate sya ng metabolism from other substances taken currently with it]
Warfarin – has anticoagulant effect [to prevent coagulation/ hindi magkaroon ng blood cloth that will cause pagbara ng cloth especially in the heart that will lead called embolism or thrombosis]
Thrombosis – coagulation
Explain what happen here
Phenobarbital agonist
Sodium Bicarboate – antagonist
by pharmacokinetics antagonism
Phenobarbital is an acid drug result to increased CNS function
= contraction/stimulation
Sodium Bicarboate – it will alkalinize the urine
- Decreased IONIZED
We alter the excretion of phenobarbital that antagonism
Agonist and antagonist compete for the same receptor
COMPETITIVE
antagonist activity is reversed when the agonist concentration is increased
- Reversible COMPETITIVE
antagonist dissociates very slowly, or not at all, from the receptor
- Irreversible COMPETITIVE
give example and explain REVERSIBLE COMPETITIVE
- Prazosin is a reversible antagonist of alpha1-receptor
- Who ever comes first will bind to the receptor
[alpha1-receptor + NE = vasoconstriction]
[alpha1-receptor + Prazosin = vasodilation]
give example and explain IRREVERSIBLE COMPETITIVE
- Phenoxybenzamine is an irreversible antagonist of alpha1-receptor
- Who ever has a greater number will win to bind in the receptor
[ex. When the receptor is 10 tas yung Prazosin mo 5 tas 1 lang yung NE mo Mas panalo yung prazosin kasi masmarami syang na ocuupied na receptor]
Antagonist blocks at some point in the chain of events that leads to the production of a response by the agonist
NON COMPETITIVE
explain Ca++ channel blockers, Verapamil and Nifedipine, prevent the influx of Ca++ions through the cell membrane and thus block nonspecifically the contraction of smooth muscle produced by another drug it is in non competitive
- inaabangan nya yung series of event
- can also bind in the receptor but not in the active site instead it will be in the allosteric site
Interaction of two drugs whose opposing actions in the body tend to cancel each other
PHYSIOLOGICAL
explain Histamine stimulates GI acid secretion, while Omeprazole inhibits the proton pump thus blocking this effect it is physiological
- may present of physiological process / event
si histamine pinapalabas yung acid sa katawan para makalabas need makapunta sa proton pump pero sisirain ni omeprazole si proton pump para hindi makalabas yung acid - the different between non-competitive ay may result of the final decision in the event
- The response elicited by combined drugs is EQUAL to the combined responses of the individual drugs (1 + 1 = 2) give example
ADDITION / ADDITIVE
o Alaxan – Brand name
o Ibuprofen + Paracetamol = is the content of the drug [kaya inaadd yung dalawa na ito is because gusto natin makuha yung both of the therapeutic effect of this content]
o Paracetamol – is central [sakit ng ulo]
o Ibuprofen – peripheral [sakit ng katawan]
o Kaya paguminom tayo ng alaxan the pain reliever become more general
- The response elicited by combined drugs is GREATER than the combined responses of the individual drugs ( 1 + 1 = 3) example
SYNERGISM
- SYNERGISM – if same ng activite
- Desired – because we bring down the dose in order to bring down the adverse effect but we are able to elevate it’s anti-bacterial activity
- It will be greater than the additive in the individual effect
Ex.
o Trisulfa suspension
o S1 = 100 mg + S2 = 100 mg + S3 = 100 mg = 300 mg [but because they synergism their action that means they are capable of producing the anti-bacterial activity brought about by 500 mg] [ but that 300 will not have a crystalluria kasi d mataas ang dose]
o But need ng 500 mg para magkaroon ng effect pero pag ganto kataas ang mg magkakaroon ng side effect na crystalluria
CRYSTALLURIA – the precipitation of sulfa drug in the urine kaya need mababa ang dose
But note that kahit mababa yung dose it will never sacrifice its ant-bacterial characteristic
- A drug that has no effect on the system enhances the effect of the other (0 + 1 = 2) example
POTENTIATION
Probenicid – antigout
o [nakakapagpababa ng acid]
Penicillin – antibacterial
EFFECT of this 2 drugs is
o Probenicid block the secretion or excretion of the penicillin leading to increased blood level that will undergo urinary recycling lead to longer antibacterial activity of the penicillin
o In conclusion, kung ang penicillin noon ay mayroong 6 hrs ngayon ay magkakaroon sya ng additional 6 hrs = 12 hrs effect penicilin
o PROBENICID increased the action of penicillin
o 0 + 1 kasi nagincreased si penicillin/antibacterial yun yung 1
o Probenicid yung nagincreased sa penicillin making it the 0 / hindi sya antibacterial [d sila same ng therapeutic use]
Probenicid + Penicillin = increased blood level
- The drug inhibits the effect of another due to opposite pharmacological actions (1 + 1 = 0) example
ANTAGONISM
Ex. Alcohol + caffeine = walang magdodomain resulting to cancelation of each others effect
* Alcohol – depressant
* Caffeine – stimulant
Ex. Aluminum hydroxide + magnesium hydroxide = 0
It is the example of beneficial antagonism
* Aluminum hydroxide – constipation
* Magnesium hydroxide – diarrhea
Ex. Maalox + Magnesium hydroxide = walang magdodomain resulting to cancelation of each others effect
* Maalox – antacid
* Magnesium hydroxide – diarrhea
Intentional drug interaction
SARIDON is a drug for analgesic
Contain – Paracetamol [depressant=decrease CNS/hindi ka makakapagfocus sa work may chance na ikaw ay antokin] and Caffeine [stimulant=increase CNS/paragising ka and makapagfocus ka sa work]
Non-intentional
Kapag hindi alam yung content ng gamot so syempre hindi mo maiidentify ng maayos kung ano yung need gamitin ng patient
Ex. Uminom ka ng diphenhydramine dahil gusto mo makatulog. However hindi sya magkakaroon ng effect kung marami kang na consume na sugar that makes your CNS increase lead to stimulant. = walang silbe kumbaga yung gamot
- the effect of the drug gradually diminishes when given continuously or repeatedly
o Parang ipis at lamok kahit anong spray mo hindi sila nauubos lahat ganun din ang drug kaya hindi natin sila pede itake ng mahabang panahon
o That will result to NO EFFECT of the drugs
- DESENSITIZATION AND TACHYPHYLAXIS
- describes a more gradual decrease in responsiveness to a drug
o Almost similar to densitation and tachyphylaxis
o Parang paginom ng kape nung umpisa pag uminom ka gising na gising ka pero pag nagtagal nawawala na yung effect ng stimulation sadalas mong paginom nito
o Nagdadagdag ka pa ng mga dose para lng makuha mo yung desired effect mo pero yung other effects d na mamalayan
o Ex. Alcohol – tolerance [kung gano kadami yung shot para Makita kung gano kataas tolerance mo]
- TOLERANCE
- used to describe the loss of effectiveness of antimicrobial or antitumor drugs
o Same to tolerance pero madalas pinaguusapan pag involve ang antimicrobial or anti-tumor drug
- DRUG RESISTANCE
a beneficial therapeutic response that arises from psychological factors
- PLACEBO
o As a control in the specific evaluation of drugs
o To benefit/please a patient not by any pharmacological actions, but by psychological means
o To patients with mild psychological disorders who attribute their symptoms to physical disease
Believing that ikaw ay gagaling pagininom mo yung gamo = placebo
- Increase concentration = Increase response
- It is characterized by the magnitude of resistance increasing continuously with a greater concentration of unbound drug at the receptor site.
- Greater receptor has been occupied the greater the response kaya graded response
“GRADED” RESPONSE
- are the proportion of receptors not needed for the production of the maximal response
Spare receptors
- Maraming dose to have effect
- 500 receptor need ng 1000 ligand kasi mababa yung binding capacity nung drug / need ng maraming ligand para maoccupied yung available receptor
- Drugs with low binding affinity have a high Kd
- Konting dose to have an effect
- 500 receptor are occupied means 500 and ligand ang present/nagbind kasi may mga ligand na low kanilang capacity [1 is to 1]
- Drugs with high binding affinity have a low Kd
- refers to the concentration (EC50) or dose (ED50) of a drug required to produce 50% of that drug’s maximal response.
POTENCY
- the relationship between receptor occupancy and its ability to initiate a response. The graded dose-response curve indicates the maximal efficacy of a drug.
EFFICACY
- Graphically plots the percent of the population that responds to a drug versus the drug dose
QUANTAL DOSE-RESPONSE RELATIONSHIP
is the observable response that can be described only in terms of an all or none event.
* Indicates potential variability of responsiveness among individuals
* It may be used to generate information regarding the margin of safety
QUANTAL RESPONSE
The dose at which 50% of the individuals exhibit the specified quantal effect
o MEDIAN EFFECTIVE DOSE (ED50)
The dose required to produce a particularly toxic effect in 50% of animals
o MEDIAN TOXIC DOSE (TD50)
The dose with which the toxic effect is death to 50% of the population
o MEDIAN LETHAL DOSE (LD50)
- Also called the MARGIN OF SAFETY
- The ratio of the lethal doses to 50% of the population over the median effective dose
THERAPEUTIC INDEX
- The higher the TI, the safer the drug; the lower the TI, the greater the possibility of toxicity
- Example: TI for barbiturates as a class is 10; for cardiac glycosides 3.0
Example yung kanina sa pic above LD50 is 120mg and ED50 is 4mg ngayon divide then
120mg/4mg = 30 mg meaning that 30x pa bago mareach ang toxicity
If the TI is low ex. 3 ibig sabihin 3 dose lng high na yung level of toxicity
dose that have daughter index sila yung mababa yung therapeutic index sila yung kahit na 2x lang delikado.
HIGH ALLERT MEDICATION
