The Principles Of Pharmacodynamics And Pharmacodynamics Definition

Pharmacodynamics Definition is the study of drug activity against living organism, especially the way it works, the reaction mechanism and physiology, as well as the therapeutic effect caused.

1. Mechanism Of Action Of Drugs

although much is known about the effects of the drug in the human body against, but not all of the mechanism can be understood properly.

Its Mechanism Of Action Of Drugs In General :

a. Drug mechanism of action in physics is can cause the occurrence of a change of physical properties of cells or organs of the body. for example :

1. Osmotic Laxative

i.e. by pulling water from the surrounding areas so that the contents of the intestine gets larger and the consistency of the contents of the intestines is reduced so that it stimulates the Peristaltic movement of the intestine faster and accelerate its expenditure (magnesium, sulfate, sodium sulfate and others).

2. Osmotic Diuretics

i.e by increasing osmotic pressure ultra filtration in the kidneys causing diuresis effects (Sorbitol, Manitol, and others).

3. Inhalation Of Anesthetics

that is the drug dissolves in fatty layers of the cell membrane and change permeability membrane, thus causing the trans-for oxygen and nutrient substances is disturbed. so that led to the loss of feeling or pain.

b. The Working Mechanism Of Drug Is Chemically

mechanism of action of the drug is chemically happens chemical reaction between endogenous substances with drugs.

for example : antacids, that is generally a weak base which reacts with stomach acid thereby reducing the acidity of the gastric fluid.

c. Working Mechanism Of Drugs That Interfere With The Process Of Cell Metabolism

for example : antibiotics; interfere with bacterial cell wall the process formation so that its growth is disrupted.

d. The Mechanism Of Action Of Drugs With Competition With Endogenous Substances To Occupy The Receptors.

for example : antihistamines compete with the endogenous histamine to occupy the receptors so that the allergic reaction is inhibited.

2. Drugs Receptors

drug receptors are divided into 3 groups, namely :

a. Chemical Properties

the main components of drug receptors are generally in the form of protein or nucleic acid which will bind with molecules of the drug.

b. Relationship Of Structure-Activity

the chemical structure of a drug closely related to the affinity against receptors, so that small changes in the molecules of the drug can cause huge become in the nature of the pharmacology.

c. Receptor Blocker

chemical structure of the drug that is similar to the hormone, the hormone receptors able to occupy so blocking the hormone activity.

for example :

1. B-Blocker will compete with the endogenous Non-adrenaline to occupy B1 and B2 receptors (propanolol).

2. H1 Blockers will compete with histamine for the H1 receptors occupied (antihistamine)

d. Drug-Receptors Interactions

the bond between the drug with the receptor is usually a weak bond, according to the theory of the receptors occupation that the intensity of the effect of the drug is directly proportional to the fraction of receptors occupied or the power and intensity of the effect reaches a maximum when the entire the receptors occupied by drugs.

the relationship of the dose with the intensity of the effect in the real state of the affairs is not simple because of the many drugs work in complex in generating effects, effects of anti-hypertension for example : is a combination of the effects of drugs against heart, vascular system and the nerves.

3. The Therapeutic Effect Of Drugs

not all drugs are actually cure diseases,many of which are simply negate or alleviate symptoms, so it can be differentiated by type of treatment.

3 Type Of Treatment

a. Causal Therapy

i.e. therapy with negating the causes of disease, in particular the destruction of germ or parasites (e.g. antibiotics)

b. Simtomsis Therapy

i.e. only eliminate or alleviate the symptoms of the disease, the deeper reason is not affected (for example : analgesics )

c. The Substitution Therapy

i.e. drugs replace substances that are generally created by a sick (e.g. insulin)

4. The Effects Of Unwanted Medications

a. Side Effects

side effects of a drug is anything undesirable drug efficacy for therapeutic purposes is at the recommended dose. For example ; nausea, vomiting, drowsiness and other

b. Allergies

allergy means "applies different" and may be based on a disorder of the immune system of the body that serves to protect the organism from foreign substances into the body.

Allergy Reactions :

1. when a foreign protein (antigen) enter repeatedly into the bloodstream of someone who is hypersensitive (heredity), then B-cell will produce antibodies (IgE) and committing yourself on mast-cell.

2. when the same antigen again into the body, then there was the merger of the antigen-antibody so that could lead to the breakup of mast-cell and liberating histamine. cross-allergies can occur between substances with similar chemical structure, for example with the sulfonamides derivatives, penicillin and the down and others.

5. Toxic Effects Of Drugs

generally the toxic effect of the drug is directly related to high dosage, because each drug in dosage, because every drug in high enough doses can cause toxic effects.

teratogen effect is an effect of the drug on therapeutic doses for pregnant women resulted in defects in the fetus. most damage occurred during pregnancy. during the 12 weeks of the beginning of pregnancy (weeks 3 to 8 weeks), because at that time formed the organs of the body such as the feet, hands and other vital organs. the drug which is suspected of have the effect of teratogenetic among others; the barb-ital, amphetamines, setosal, sulfonamides and others.

6. Tolerance. Habituation And Addiction

Tolerance

is the event where the dose must be offered up continuously to achieve the effect of the same therapeutic.

Habituation

drug tolerance is due to having a certain medication (factor habits)

Addiction

are the symptoms of addiction or drug addiction where patients want to use keep the drug. for example : heroin, morphine, cocaine and others.

7. A Combination Remedy

the two drug are used at the same time can influence each other drug works, namely :

a. The Antagonism

the antagonism that is first drug activities are reduced or abolished completely by the second drug that has an effect of Pharmacology to the contrary.

b. Synergism

synergism is a joint venture between the two drugs, there are 2 types of synergism :

1. Addition or Sumac

addition or sumac is a combination effect is equal to the sum of the activities of each drug. for example :asetosal, with paracetamol.

2. Potentiate

potentiate that is the first drug activities were reinforced by a second drug or vice versa. for example : estrogen with progesterone, trimetoprim with sulfametoksazol.

The Principles Of Pharmacodynamics And Pharmacodynamics Definition