1. Introduction to Pharmacology

Question 1

What is Pharmacology?

Answer 1

The study of the effects of drugs on the function of living systems.

Question 2

What is a drug?

Answer 2

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.

Question 3

What the difference between a drug & a poison?

Answer 3

• The Dose
• “The dose makes the poison”

Question 4

What is Toxicology?

Answer 4

The study of toxic effects of chemicals, including drugs.

Question 5

Pharmacology is divided into:

Answer 5

1. Pharmacodynamics
2. Pharmacokinetics

Question 6

Pharmacodynamics

Answer 6

• ‘What the drug does to the body’
• Describes the events consequent on interaction of the drug with its receptor or other primary site of action.

Question 7

Pharmacokinetics

Answer 7

• ‘What the body does to the drug’
• The time course of drug concentration following dosing depends on the procuresses of absorption, distribution, metabolism & excretion (ADME).

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Question 8

What do you know about the nature of drugs?

Answer 8

• Drugs vary widely with respect to:

1. Molar mass (e.g. lithium 6.941 mg/mol, insulin 5,793.6 g/mol)
2. Chemical structure & configuration (including isomers)
3. Chemical nature (reactive/inert, weak acid/weak base)
4. Sources (synthetic, natural products, & biopharmaceutical)

Question 9

What does the Pharmacology of a Drug include?

Answer 9

1. Molecular structure
2. Physiochemical properties
3. Biological actions
4. Mechanism of action
5. Pharmacokinetics (what the body does to the drug)
6. Therapeutic uses
7. Adverse effects
8. Drug-drug interactions

Question 10

What do you know about drug specificity?

(Silver bullets?)

Answer 10

• For a drug to be useful as either a therapeutic or scientific tool, it must act selectively on particular cells and tissues (i.e. it must show a high degree of binding site specificity).
• Conversely, proteins that function as drug targets generally show a high degree of ligand specificity.
• No drug acts with complete specificity.
• In general, the lower the potency of a drug & the higher the dose needed, the more likely it is to interact with sites of action other than the intended site of action. This leads to ‘off-target’ side effects.

Question 11

What are the Properties of an Ideal Drug?

Answer 11

• An ideal drug should be:

1. Effective
2. Safe
3. Stable in storage
4. Predictable in action
5. Easy to administer
6. Free from interaction with other drugs
7. Inexpensive
8. Not given on an indefinite basis

Question 12

What are the Classification of Drug Effects?

Answer 12

• Therapeutic Effect: Desired effect
• Side Effect: Any effect other than the desired one
• Adverse Effect: Side effects that are harmful
• Toxic Effects: Adverse effects resulting from (toxic) overdose
• Idiosyncratic Effect: Abnormal response to a drug that occurs in only a small minority of individuals.

Question 13

What are the two objectives of drug therapy?

Answer 13

• To provide maximal benefit with minimal harm to the patient & at an affordable cost.
• Therapeutic decisions are often influenced by the risk-benefit ratio. (weighing the beneficial effects against harmful effects & cost to the patient).