PHARMACOLGY- PHARMACODYNAMIC

1. FINC NURSING
CHOACHING AGRA
TOPIC-
PHARMACODYNAMIC

2. PHARMACODYNAMIC -
IN GREEK WORD-
PHARMACON- DRUG
DYNAMICS- ACTION / POWER

3. DEFINITION-
• IT IS THE STUDY OF BIOCHEMICAL AND
PHYSIOLOGICAL EFFECTS OF DRUGS THEIR
MECHANISM OF ACTION AT ORGAN LEVEL
AS WELL AS CELLULAR LEVEL .
• PHARMACODYNAMICS IS THE STUDY OF
DRUG EFFECTS .
• IT STARTS WITH DESCRIBING WHAT THE
DRUGS DO , AND GOES ON TO EXPLAIN
HOW THEY DO IT.

4. CONT…
• ACTION- HOW AND WHERE THE EFFECT IS
PRODUCED A CALLED AS ACTION.
• EFFECT- THE TYPE OF RESPONSE PRODUCING
BY DRUG.

5. PRINCIPLES OF DRUG ACTION-
• THE BASIC TYPES OF DRUG ACTION CAN BE
BROADLY CLASSES AS(TYPES OF
RESPONSES)-
1- STIMULATION
2-DEPRESSION /INHIBITION
3-IRRITATION
4-REPLACEMENT
5-CYTOTOXIC ACTION

6. 1- STIMULATION-
• SELECTIVE ENHANCEMENT OF THE LEVEL OF
ACTIVITY OF SPECIALIZED CELLS.
-ADRENALINE STIMULATES HEART
-PILOCARPINE STIMUTES SALIVARY GLSANDS

7. 2- DEPRESSION/ INHIBITION-
• SELECTIVE DIMINUTION OF ACTIVITY OF
SPECIALIZED CELLS .
-BARBITURATES DEPRESS CNS
- QUIDINE DEPRESS HEART
-OMEPRAZOLE DEPRESSED GASTRIC ACID
SECRETION

8. 3- IRRITATION-
• THIS REFERS A NONSELECTIVE , OFTEN
NOXIOUS EFFECT AND IS PARTICULARLY
APPLIED TO LESS SPECIALIZED CELLS
(EPITHELIUM , CONNECTIVE TISSUE) .
• STRONG IRRITATION RESULT IN
INFLAMMATION , CORRSION , NECROSIS
AND MORPHOLOGICAL DAMAGE .

9. 4-REPLACEMENT-
• USE OF NATURAL METABOLITIES ,
HORMONES OR THEIR CONGENERS IN
DEFICIENCY STATES.
- LEVODOPA IN PARKINSONISM
- INSULIN IN DIABETES MELLITUS
- IRON IN ANEMIA

10. 5-CYTOTOXIC ACTION-
• SELETIVE CYTOTOXIC ACTION ON INVADING
PARASITES OR CANCER CELLS ATTENUATING
THEM WITHOUT SIGNIFICANTLY AFFECTING
THE HOST CELLS
• FOR INVADING PARASITES OR CANCER
CELLS.
• UTILIZED FOR CURE/ PALLIATION OF
INFECTIONS AND NEOPLASMS .
• EXAMPLE- PENICILLIN ,CHLOROQUINE ,
ZIDOVUDINE

11. MECHANISM OF DRUG ACTION-
• 1- RECEPTOR MEDIATED MECHANISM-
-RECEPTOR – MACROMOLECULES
PRESENT ON THE CELL SURFACE .
CYTOPLASM OR IN THE NUCLEUS –
DRUG BIND AND INTERACTS TO
PRODUCE CELLULAR CHANGES
EXAMPLE –ADRENERGIC RECEPTOR
(ALPHA AND BETA ).

12. CONT..
• - AFFINITY –ABILITY OF THE DRUG TO GET
BOUND TO THE RECEPTOR.
• - INTRINSIC ABILITY- ABILITY OF THE DRUG TO
PRODUCE PHARMACOLOGICAL ACTION AFTER
COMBING WITH THE RECEPTOR.
• - AGONIST -DRUG THAT HAVE CAPABLE OF
PRODUCING PHARMACOLOGICAL ACTION AFTER
BINDING TO RECEPTOR AGONIST HAS HIGH
AFFINITY AND HIGH INTRINSIC ACTIVITY
EXAMPLE- MORPHINE

13. CONT….
- ANTAGONIST – DRUG THAT PREVERTS OF
AGONIST TO ITS RECEPTOR OR BLOCK ITS EFFECT
.
ITS DOES NOT PRODUCE ANY EFFECT ITSELF
- COMPETITIVE ANTAGONIST- DRUG HAS HIGH
AFFINITY WITH OUT INTRINSIC ACTIVITY
- PARTIAL AGONIST –A DRUG THAT BIND TO THE
RECEPTOR BUT PRODUCE AN EFFECT LESS THAN
THAT OF AN AGONIST , IT BLOCK EFFECT OF
AGONIST.

14. CONT…
• INVERSE AGONIST- IT HAS FULL AFFINITY
TPWARD THE RECEPTOR BUT PRODUCE
EFFECT OPPOSITE TO THAT OF AN AGONIST.

15. 2- NON RECEPTOR MEDIATED
MECHANISM-
• - BY PHYSICAL ACTION-
• A- OSMOSIS- ACT AS EXERTING AN OSMOTIC
EFFECT EXAMPLE – 20 % MANNITOL IN
CEREBRAL EDEMA .
• B- ABSORPTION- ACTIVATED CHARCHOL
ABSORBS TOXIN HENCE IT IS USED IN THE
TREATMENT OF DRUG POISONING .

16. CONT….
• C- DEMULCENT- COUGH SYRUP PRODUCE A
SOOTHING EFFECT IN PHARYNGITIS BY
COATING THE INFLAMED MUCOSA.
• D-RADIOACTIVITY – RADIOACTIVITY ISOTOPS
EMIT RAYS AND DESTROYS THE TISSUE.

17. CONT…
• -BY CHEMICAL ACTION –
• A- ANTACIDS ARE WEAK BASES- NEUTALISE
GASTRIC ACID – USEFUL IN PEPTIC ULCER
EXAMPLE – ANTACID , ENO
• B- METAL- LIKE IRON , COPPER , MERCUTY
ARE ELIMINATED FROM THE BODY WITH THE
HELP OF CHELATING AGENT .

18. CONT…
• - THROUGH ENZYME- DRUG ACT BY
INHIBITING THE ENZYMES ACTIVITY EXAMPE-
ACE INHIBITOR SUCH AS CAPTIPRIL ,
ENAPRIL.
• – THROUGH ANTIBODY PRODUCTION –
VACCINE PRODUCE THEIR EFFECT BY
STIMULATING THE FORMATION OF
ANTIBODIES EXAMPLE – VACCINE AGAINST
TUBERCULOSIS.

19. CONT….
• TRANSPORTERS – SOME DRUG PRODUCE
THEIR EFFECT BY BINDING TO TRANSPORTERS
EXAMPLE – SSRIs- BIND TO 5-HT – BLOCK 5-
HT REUPTAKE INTO NEURON –
ANTIDEPRESSANTS EFFECT .