The lecture for undergraduate students

1. By:
Seragaldin M. Abdulqader
Clinical pharmacology for nurses
University of Raparin/school of nursing
The lecture for undergraduate students:
2015 -2016 1

2. Definition
A route of administration in pharmacology
and toxicology is the path by which a drug,
fluid, poison, or other substance is taken
into the body.
Routes of administration are generally
classified by the location at which the
substance is applied. Common examples
include oral and intravenous administration.
29 November 2015 2

3. Definition
First Pass Effect:
When a drug is administered orally, the drug is absorbed by
the mesenteric veins. These veins drain into the portal vein
which flows into the hepatic sinusoids.
Half-life:
The amount of time required to eliminate 50% of the drug in
the body. The half-life can be determined from a semilogy
graph of the plasma concentration versus time or it can be
calculated from the elimination constant.
29 November 2015 3

4. Definition
Pharmacokinetics, sometimes abbreviated
as PK that is a branch of pharmacology
dedicated to determining the fate of
substances administered externally to a
living organism via specific route to the drug
characteristics.
29 November 2015 4

5. Pharmacokinetic
A process which formed from:
 Liberation- the process of release of a drug from the
pharmaceutical formulation
 Absorption - the process of a substance entering the
blood circulation.
 Distribution - the dispersion or dissemination of substances
throughout the fluids and tissues of the body.
29 November 2015 5

6. Pharmacokinetic
 Metabolization (or biotransformation, or
inactivation) – the recognition by the organism
that a foreign substance is present and the
irreversible transformation of parent
compounds into daughter metabolites.
 Excretion - the removal of the substances from
the body. In rare cases, some drugs irreversibly
accumulate in body tissue
29 November 2015 6

7. Routes of Administration/Enteral
1. Oral route (p.o.):
 Easy
 Usually safe
 Economical
Limitations/Risks
 Relatively slow
 Less predictable
 First pass effect
 Patient compliance
29 November 2015 7

8. Routes of Administration/Enteral
2. Sublingual (SL):
 Rapid response
 No first pass effect
 Bypasses GI acids and enzymes
Limitations/Risks
 Not used for irritating substances
 Many molecules do not penetrate oral mucosa
29 November 2015 8

9. Routes of Administration/Enteral
3. Rectal (PR):
 Unconscious patients
 Vomiting patients
 Small children
 Minimal first pass effect
 Bypasses GI acids and enzymes
Limitations/Risks
 Irregular and incomplete absorption
 Not used for irritating substances
 Solutions must be isotonic
29 November 2015 9

10. Routes of Administration/Parenteral
1. Intravenous (IV):
 Permits titration of dosage
 Lowest intra-individual variability
 Most rapid response (emergencies)
 Most suitable for irritating substances and large volumes
Limitations/Risks
 Greatest risks: overdose, anaphylaxis, infection, embolism,
vascular injury, and phlebitis
29 November 2015 10

11. Routes of Administration/Parenteral
3. Subcutaneous (s.c.):
 Slower absorption than i.m.
 Absorption slowed by vasoconstriction
Limitations/Risks
 Not used for irritating substances
 Large volumes are painful
29 November 2015 11

12. Routes of Administration/Parenteral
4. Intraperitoneal (i.p.):
 Provides large absorbing surface
 Primarily used on lab animals
Limitations/Risks
 First pass effect
 Risks: adhesions, infection, injury
29 November 2015 12

13. Routes of Administration/Parenteral
5. Topical:
 Useful for local effects
 Poisons and toxins
Limitations/Risks
 Least effective for systemic absorption
29 November 2015 13

14. Routes of Administration/Parenteral
6. Pulmonary
 Very rapid absorption
 Useful for gases, vapors, aerosols
Limitations/Risks
 Not used for irritating substances
 Difficult to control dose
29 November 2015 14

15. 29 November 2015 15
Thank you