1. Introduction; Scope of Pharmacology Routes of Drug Administration
Pharmacology I
BMS 242
Lecture I
Introduction; Scope of Pharmacology Routes of Drug Administration
Dr. Aya M. Serry
2016

2. 10 20 40 100 SUBJECT GRADE Quizzes First Assessment Exam
Second Assessment Exam
Self Learning (Project)
Final Exam 40
TOTAL
100

3. Course Objectives
Upon Completion of this course you should be able to:
Recognize the different routes of drug administration and the advantages and disadvantages of each one
Recognize the fundamental principles of pharmacodynamics (i.e. drugreceptor interactions) and pharmacokinetics (i.e. absorption, distribution, metabolism, and elimination of drugs).
Identify how drugs alter cellular function through the study of pharmacodynamics.
Determine how the body handles drugs through pharmacokinetic processes such as absorption, distribution, metabolism, elimination, dose-response relationships, half-life, steady-state concentrations and volume of distribution.
Describe the pharmacology of the autonomic nervous system at an introductory level as preparation for understanding CNS drug actions.
Describe the distribution and identify the function of clinically relevant receptors in the autonomic nervous system and identify why they represent useful targets for therapeutic manipulation.
List and discuss selected drugs used to stimulate or inhibit the sympathetic or parasympathetic nervous systems, including their clinical uses and potential adverse effects.
Name major classes and provide specific examples, mechanisms of action, adverse effects and contraindications for drugs affecting the autonomic nervous system and central nervous system.
Explain the indications, mechanism of action, adverse effects, contraindications and potential drug interactions of Aspirin, NSAIDs and Acetaminophen
Explain the mechanism of action of CNS depressants (Anxiolytics) and CNS stimulants and their clinical uses

5. Lecture Objectives Understand what’s Pharmacology
Identify the difference between Pharmacokienetics and Pharmacodynamics
Define what’s a Drug and its nature
Differentiate between different routes of drug administration and their advantages vs. their disadvantages

6. Different routes of Administration From different Sources
Introduction
Different routes of Administration ?
Drug
Living System
Effect
From different Sources
Treatment
Prevention
Diagnosis
Pharmacology: The science that studies the effects of the drug on living systems and How? the drug produces these effects

7. Introduction Drug Effects of the Drug How the Drug acts
Therapeutic effects
Adverse effects
Factors affecting Drug effects
Mechanism of action
Therapeutic Indications
Contra-Indications
Drug Interactions
Pharmacokinetics

8. Definitions Pharmacodynamics Pharmacokinetics Pharmacotherapeutics
Effect of the Drug on the Body
Effects of the body on the drug
Proper selection & use of the Drug to treat or prevent a disease

9. Nature of the Drug
A Drug is any substance (other than nutrients and essential dietary ingredients) which when administered to a living organism, produces a biological effect
Drug
Synthesized within the Body
Not synthesized within the Body
(Xenobiotics)
Synthetic
Hormones
Enzymes
Neurotransmitters
Obtained from Natural Products (Plants or Animals)
Obtained through Genetic Engineering

10. Mechanisms of Drug Action
How Does a Drug Acts?
Interaction with Protein Targets
Chemical
Physical
(Drug Targets)
Neutralization
Chelation
Adsorbtion
Osmosis
Receptor
Ion Channel
Enzyme
Transporter (Carrier)

11. Routes of Drug Administration
Drug’s route of administration is determined by:
Major routes of drug administration include Enteral, Parenteral,
and Topical routes
Properties of The drug
( e.g.: Water and lipid Solubility , Ionization…etc.)
Therapeutic Objectives
Rapid onset of action
Need for long term treatment
Restriction of delivery to a specific site

12. Routes of Drug Administration

13. Routes of Drug Administration
Enteral Route: Administering a drug by mouth
Drug dosage form is swallowed allowing oral absorption through GIT (Oral)
Drug dosage form may be placed topically, facilitating direct and rapid absorption into the blood stream. this includes:
Under the tongue (Sublingual)
Between the gums and inner cheeks lining (Buccal)
given by suppository or enema (rectal)

14. Advantages of the Oral Route:
Simplest and most common route of administration
Can be self administered
Overdose easily overcome with antidote (e.g.: Charcoal)
Cheap (compared to most parental routes)
Large surface area for absorption
Pain free, Convenient to patients

15. Oral Route Disadvantages of the Oral Route:
Drug is Subjected to First Pass Metabolism (First Pass Effect)
Gastric acidity may limit absorption
Drug can be irritating to GIT
Drug-Drug interaction (e.g: sedatives with antihistaminic) and Drug-Food interaction (e.g: Ciprofloxacin with dairy products) influencing drug activity
Effect is too slow for emergency
Can’t be given to unconscious patients

16. Disadvantages of the Oral Route:
First Pass Effect
Most of drugs absorbed from GIT enter the portal (liver) circulation before they are distributed to the systemic (general) circulation
The drug will be metabolized in the liver before reaching the target organ, decreasing drug efficacy. E.g.: Nitroglycerin is 90% cleared during a single passage through the liver (that’s why nitroglycerin in not administered orally)
Thus the dose of a drug that has high first pass effect should be increased to ensure that enough dose reaches the target organ

17. Sublingual & Buccal Routes
Advantages:
Avoiding First Pass Metabolism
Avoiding destruction of the drug by GI acidity
Rapid Absorption through capillary network directly into systemic circulation
Disadvantages:
Small dose limit
Bad taste of drug
Irritation of oral mucosa

18. Rectal Route Advantages: Disadvantages:
Partially by-passes first-pass effect (50 %)
Bypasses destruction by stomach acid
Ideal if drug causes vomiting
Ideal in patients who are vomiting, or unconscious patients
Disadvantages:
Drugs may irritate the rectal mucosa
Not a well-accepted route ( low patient compliance)

19. Conclusion
Pharmacology is the science that studies the effects of the drug on living systems and how the drug produces these effects
A Drug is any substance (other than nutrients and essential dietary ingredients) which when administered to a living organism, produces a biological effect and it can be either natural or synthetic in nature
The major routes of drug administration include Enteral, Parenteral and Topical routes; each route has its advantage over the other one depending on the properties of the drug used and the therapeutic objectives needed