Department of Pharmaceutical Department of Pharmaceutical sciencessciences

33rdrd Semester Semester

Group membersGroup members

Mohammad AsadMohammad AsadHafiz JunaidHafiz JunaidAmir Sohail KhanAmir Sohail KhanSana MushtaqSana Mushtaq

What is Pharmacodynamics Drug response curve EC50 Potency Efficacy Refrences

Pharmacodynacmics describes the action of drug on body and influence of drug concentration on magnitude of response

Most of drugs exerts effect by ineracting with receptor

An agent that can bind to recepor and produces iological rsponse is called as agonist

The interaction between drug and its receptor can be described by a curve called as drug response curve

on Vertical axix there is response of drug

On horizontal axix there is concentration of dose

The magnitude of drug effect depends on drug concentration at receptor site and this availbilty and concentration of drug at receptor is determined by both dose of drug administered and by drug pharmacokinetics(ADME)

When no drug is added then no effect is produced

When some drug is added then we get response

By adding more drug we get maximum response

A time will reach on which adding more drug will not cause increase in response because we have reached to maximum effect

EC50EC50Is concentration of drug needed to get half

of the maximum effect

Two important properties of drug can be found by dose reponse curve

Efficacy Potency

PotencyPotency amount of drug necessary to

produce maximum effect is the potecncy of drug

Candesartan and ibesartan are angiotensin receptor blocker

Candesartan is more potent then Ibesartan because the dose range for candesartan is 4 to 32 mg as compared to dose range of ibesartan whose dose range is 25 to 300 mg

Ability of a drug to elicit a response when it interacts with a receptorEfficacy is dependent on;

the number of drug-receptor complexes formedefficiency of the coupling of receptor activation to

cellular responses. Maximal efficacy of a drug assumes that all

receptors are occupied by the drug and if more drugs are added, no additive response will be observed.

Maximal response (efficacy) is more important than drug potency.

A drug with greater efficacy is more therapeutically beneficial than the one that is more potent.

Lipincott pharmacology

Rang and dales pharmacology