‫بسم هللا الرحمن الرحيم‬

‫‪Pharmacology‬‬
 Topics to be Covered in semester I

Pharmacological Concepts
❖ Introduction to Pharmacology
❖ Routes of drug administration.
❖ Pharmacokinetics: Absorption - Distribution – Metabolism –
Elimination
❖ Pharmacodynamics: Protein targets for drug binding – Receptor
types – drug antagonism

Drugs Acting on the Autonomic Nervous System:

❖ Parasympathetic drugs (Cholinergic Agonists and Antagonists)
❖ Sympathetic drugs (Adrenergic Agonists & Antagonists).
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Topics to be Covered in semester I
❖ Cardiovascular drugs:
• Diuretics
• Antihypertensive.
• Antianginal drugs.
• Drugs for treatment of heart Failure.
• Drugs acting on the Blood: Antiplatelet – anticoagulant and
thrombolytics.
• NSAIDs and Antihistamines.

EXAM
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 Topics to be Covered in semester II

❖ GIT Pharmacology: Peptic ulcers - Chemotherapy-induced emesis –

Diarrhea - Constipation.
❖ Respiratory Pharmacology: Asthma, cough, decongestant.

❖ Endocrine Pharmacology:
❖ Drugs for Diabetes mellitus (DM).
❖ Thyroid and Antithyroid Drugs.
❖ Adrenal Steroids.
❖ Estrogens Progestogens and Androgens.

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Topics to be Covered in this semester
❑CNS Pharmacology:
❖ Pharmacologic management of Parkinsonism.
❖ Antiepileptic Drugs.
❖ Antidepressant Agents
❖ Antipsychotic Drugs
❖ Opioid Analgesics.
❖ General and local anesthetics.

EXAM
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 Pharmacology
References

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 What is PHARMACOLOGY?

Pharmacology is the science of drugs.

(Greek: Pharmakon—drug; logos—study).

Pharmacology can be defined as the science that

concerned with the effects of drugs on the function of
living systems.

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 Definitions
 A Drug can be defined as a chemical substance
of known structure, other than a nutrient or an
essential dietary ingredient, which, when
administered to a living organism, produces a
biological effect.
 A medicine is a chemical preparation, which
usually but not necessarily contains one or more
drugs, administered with the intention of
producing a therapeutic effect.

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 Definitions
 Pharmacokinetics is the science of the
relationship between the movement of a drug
through the body and the processes affecting this
movement (Absorption, Distribution, Metabolism
and Excretion, ADME).
 (It is about what the body does to the drug).

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The four processes of pharmacokinetics: absorption, distribution, metabolism, excretion
 Definitions
 Pharmacodynamics: the study of effects of
chemicals and drugs on living system and the
study of mechanisms of these effects.
 This describes the action of the drug on the
body, including receptor interactions, dose
response phenomena, and mechanisms of
therapeutic and toxic action.
 (it is about what the drug does to the body)

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myosin light-chain kinase
 Definitions
 Medical Pharmacology: is defined as the
science of substances used to prevent,
diagnose, and treat disease.
 Therapeutics: is the use of drugs to prevent,
diagnose or cure disease.
 Toxicology: is that branch of pharmacology
which deals with the undesirable effects of
chemicals on living systems, from individual
cells to complex ecosystems.

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Routes of drug administration
 Routes of drug administration
 Routes of drug administration are
classified into:
1. Enteral (through the GIT).
2. Parenteral means not through the
alimentary canal and commonly refers to
injections.
3. Topical application through epithelial
surfaces (e.g. skin , cornea, vagina and
nasal mucosa).
15 4. Inhalation.
 Routes of drug administration
 Enteral routes include:
A. Oral.
B. Buccal.
C. Sublingual.
D. Rectal.

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 Routes of drug administration
 Parenteral includes:
A. Intravenous (I.V).
B. Intra-arterial.
C. Intracardiac.
D. Subcutaneous (S.C e.g. insulin).
E. Intraosseous (in the bone marrow emergency
in pediatric).

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 i

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 Routes of drug administration
F. Intradermal (skin testing).
G. Intrathecal (into the spinal cord) e.g.
anesthesia.
H. Intraperitoneal (infusion or injection into
the peritoneum e.g. Peritoneal dialysis).
I. Intravesical (i.e. infusion into the urinary
bladder).
J. Intravitreal (inside an eye).
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 Intraperitoneal

20 Intrathecal
Intravitreal
 Oral administration
Advantages:
1. Convenient, (portable, no pain , easy to take).
2. Cheap no need for sterilization.
3. Variety (fast release tabs, slow release tabs,
capsule enteric coated tablet, syrup, suspension).
Disadvantage:
1. Sometimes inefficient, some drugs have poor
bioavailability (only part of the dose may be
absorbed) or (excessive first- pass effect e.g.
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propranolol and morphine).
 Oral administration
2. Food and GI motility can affect drug absorption.
Often patient instructions include a direction to
take with food or take on an empty stomach e.g.
Tetracycline and penicillin preferred with empty
stomach, while propranolol bioavailability is
higher after food ,griesofulvin absorption is
higher after a fatty meal.
3. Unsuitable for unconscious patients (esp. solid
dosage).

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 Buccal /Sublingual
 Some drugs are taken as smaller tablets
which are hold in the mouth or under tongue
(usually harder tablets) disintegration rate 4
hrs e.g:
1. Nitroglycerin and isosorbide dinitrate.
2. Testosterone.
3. Oxytocin.
4. Nicotine containing chewing gum (use for
cigarette smoking replacement).
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 Buccal /Sublingual
Advantages:
1. No loss of drug by first–pass effect.
2. Rapid absorption.
3. Drug stability (pH in mouth relatively neutral
thus drug may be more stable).
Disadvantages:
1. Holding the dose in the mouth is inconvenient,
if any is swallowed that portion must be treated
as an oral dose and subject to first-pass
metabolism.
2. Only smaller dose is recommended.
 Rectal
 Most commonly by suppositories or enema, some
drugs given by this route include paracetamol,
indomethacin, and miconazole.
Advantages:
1. Bypass liver so reduce the first pass effect.
2. Useful for patients unable to take drugs orally
e.g. infants (less than 4 months).
Disadvantages:
1. Erratic absorption.
2. Not well accepted.
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 Intravenous Injection (I.V)
Advantages:
1. Rapid quick response.
2. Large doses can be given.
Disadvantages:
1. It may be difficult to find a suitable vein.
2. Because of rapid response, it may be toxic.
3. Required trained personnel.
4. Expensive (sterility, pyrogen free ---
increase the manufactory cost).
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 Intramuscular (I.M)
Advantages:
1. Large volume than SC can be given by I.M.
2. A depot or sustain release effect is possible with
I.M. injection (e.g. Depo-Provera and procaine
penicillin).
Disadvantages:
1. trained personnel is required for injection.
2. absorption is sometimes erratic specially for
poorly soluble drugs (e.g. Diazepam, phenytoin).
3. the solvent may be absorbed faster than the drug
causing precipitation of the drug at the site of
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injection.
 Subcutaneous (S.C)
 This involves administration of the drug dose
just under the skin.
Advantages:
1. Can be given by the patient e.g. Insulin .
2. absorption slow but usually complete, improve
by massage or heat.
Disadvantages:
1. Can be painful.
2. irritant drugs can cause local tissue damage.
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 Inhalation
 Either use for local effect e.g. Bronchodilators
or for systemic effect e.g. general anesthetics,
it gives rapid absorption by passing the liver.
 Absorption of gasses is relatively efficient;
however, solids and semisolids are excluded if
larger than 20 microns. Cromolyn is taken as
powder for inhalation.

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 Topical
 Either use for local effect (e.g. Eye drop ,
antiseptics, sunscreen).
 Or for systemic effect (e.g. Nitroglycerin –
transdermal patches).

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