Q. Define Pharmacodynamic And Pharmacokinetic And Explain The Route Of Administration With Advantages And Disadvantages?
Ans :-
• Pharmacodynamic:- It deals With the study of physiology and biochemical effect of drug and their mechanism of action.
• Pharmacokinetics:- It deals with the study of Absorption , distribution , metabolism and excretion ( ADME ) of drug .
• Route Of Administration :-
- Two Types
1) Local (Topical)
2) Systemic
2) systemic
A) oral
B) anal / rectal
C) sublingual
D) parental
E) cutaneous
1) Local or topical route of administration:-
This route can be used for local action of drug whose systemic Absorption from this side is minimum.
It is simplest route .
In this technique the drug absorption through intact of skin depend upon liquid solubility drug.
The drug used for local application are dusting powder , lotion , paste , ointment, cream , gel , etc .
This site where drugs are applied are skin , eye , nose , ear .
2) systemic route of administration:-
A) oral route of administration :-
This is most commenly used route .
The drugs are administered is a simple dosage form like tablet, capsule, solution, suspension,syrup,etc.
• Advantages :-
1) safe route of administration.
2) it is a patient convenient.
3)self medication are possible.
4) it is economically chipper.
5) easy to swallow.
6) fixed dose or unit dosage form.
• Disadvantages:-
1) it is complicated route for pediatrics and pediatric patient.
2) this route can't be used if patient is unconscious.
3) 100% absorption is not possible because the drug is degraded or distroyed by digestive enzyme.
4)onset of action is very slow.
5) irritant , bitter , unpalatable drugs can't be given .
6) in condition like nausea and vomiting those route can't used .
7) not useful in emergency cases.
8) high dose are effective.
B) Sublingual/ Buccal Route Of Administration:-
The tablet or pellets containing the drug is placed under the toungue or crushed in mouth and spread over buccal mucus.
In this technique the medicament not be swallowed .
• Advantages:-
1) onset of action is very quick
2) overdose can be avoided
3) 100% absorption is possible
4) enzymatic degradation is avoided .
5) easy to administration
• Disadvantages:-
1) irritating drug are avoided
2) only are lipid soluble drug are used .
C) parental route of administration:-
This route of administration is discussed as - 1) intradermal
2) intravenous
3) subcutaneous
4) intramuscular
• Advantages ;-
1) onset of action is very quick
2) the drugs can be administered in unconscious patient
3) the patient having nausea and vomiting the drug can be administered by this route .
4) 100% absorption is possible
5) first pass metabolism is avoided
6) low dose are effective
7) irritant or unpatentable drug can be given
• disadvantages:-
1) it is costly route
2) inconvinient
3) self medication are not possible
4) skilled person required
1) intradermal :-
In this administration the drug is incorporated or injected in the dermal layer of skin .
The drug injected in very small amount that is not more than 1ml.
2) subcutaneous:-
The drug is injected into loose connective tissue or subcutaneous layer
Generally soluble drugs are injected and irritant drugs are avoided
Upto 2ml quantity of drug can be injected
The site of injection is upper arm and thigh .
Example:- insulin , morphine, adrenaline
3) intramuscular:-
In this type of administration the drug is layer of muscle tissue
Intramuscular injection permits the drug deposition between the layers of muscle mask called as tissue depot from where the drug are slowly release and shows persistent action
4) intravenous:-
In this technique the drug is introduce directly into lumen of vein
The site of administration is the bent of elbow
The insoluble drug oily substances acid or alkaloin salt are impartible with blood. So ,they never be administered by this route .
Example:- normal saline
• Inhalation Route Of Administration:-
- Topical And Systemic Both
• Advantages:-
1) the absorption is very fast
2) it shows the local and systemic effect
3) onset of action pn local site is very fast
• Disadvantages:-
1) as the drug enters into respiratory system therefore their may be increase cardiac toxicity
2) some drugs produce the local irritation
3) the specially designed apparatus is required.
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