General Approach To Drug Administration

1. General Approach To Drug Administration

2. Drug Administration

Oral
Intramuscular Subcutanous Intravenous
Absorbtion
Tissue
Plasma water
Metabolism
Excretion
Site of Action

3.

Pharmacokinetics
Relationship between the dose of a drug
& the subsequent concentration of the
drug in body fluids & tissues over time

4.

drug absorption, passage of drug
from site of administration to
circulation
drug distribution, to where does the
drug finally pass and become
therapeutic

5.

drug metabolism, breakdown of drug
to an inactive form usually within the
liver
drug elimination, final excretion
either in urine, feces, or even
exhalation

6.

Routes of Administration
Oral, drug is delivered by mouth and absorbed
in the gastrointestinal (GI) tract
Parenteral, delivery with a needle and syringe
Inhalation, administration through the
respiratory tract
Nasal, absorption of drug by olfactory epithelia
Rectal, absorption through colon epithelium

7.

Systemic vs. Local Effects
Systemic effects mean that the delivered
drugs circulate through the entire body
Example: Orally delivered pain reliever for a
sore toe
Local effects are restricted to region of
delivery
Example: nasal spray for stuffy nose

8. Parenteral Injection Sites

Used for drugs poorly absorbed from the
gastrointestinal (GI) tract or those that are unstable
in the GI.
Also used in unconscious patients or when rapid
onset of action is required
subcutanously
intravenously
intramuscularly

9. Subcutaneous Route

Can be painful, irritant drugs can cause local
tissue damage;
Maximum of 5 ml injection thus often small
doses limit use;
Absorption depending on blood flow;
Constant & slow absorption;
Prolonged effect.
(Ex.of drugs: Insulin, Heparin,
Liposoluble vitamins)

10. Subcutaneous Injection Sites

• Abdominal wall
• Thigh
• Deltoid area

11.

Intramascular Route
Intramuscular (IM) rapid absorption of aqueous
drugs, larger volume, than SC, can be given
The site of injection will influence the absorption.
Absorption depending on blood flow
Rapid onset & shorter duration
Use at least a one inch needle to assure that the
drug is placed deep in the muscle for absorption.
This route allows for the second fastest rate of
absorption
(Ex.of drugs: Antibiotics, Spasmolytics,
Vasopressors)

12. Intramuscular Injection Sites Deltoid Muscle

13. Intramuscular Injection Sites Vastus Lateralis

14. Intramuscular Injection Sites Gluteus Maximus