General principles in PHARMACOLOGY and Mechanisms of Drug Action

MERLYN A. BARACLAN, RN, RMT

“The best cure for the body is a quiet mind.”

Napoleon I (1769-1821) Napoleon Bonaparte.

Therapeutic Methods

Diet therapy Drug therapy Physiotherapy Psychologic therapy

DRUG is a chemical administered

in an attempt to

PREVENT, TREAT OR DIAGNOSE disease

a substance or preparation used in treating disease

a chemical substance that affects the processes of the mind or body

[Dutch: droog, meaning dry]

pharmacology

OBJECTIVES OF LEARNING PHARMACOLOGY

- To realise that medicines should be prescribed safely and effectively

- To understand the ways that drugs work to affect biological systems

- To appreciate that pharmacology cannot be understood comprehensively without the parallel understanding of related biological and clinical sciences

- To provide a suitable framework to allow comparison of the relative benefits and risks of different drugs

- To be able to comprehend and participate in research

Greek: pharmakon, meaning drug, & logos, science

Deals with the study of drugs and their actions on living organisms

Is a study of the effect of chemicals on biological systems

Is the study of the biological effects of chemicals

Guiding principles when studying a DRUG in depth

1. The generic name

2. The class to which the drug belongs

3. Whether the drug is available without prescription

4. The main reasons of using the drug

5. The way the drug works

6. How the drug is given

7. Pharmacokinetics

8. Unwanted effects

9. Propensity to cause drug to drug interactions

10. Are there non – pharmacological treatments that are effective alternatives?

DRUG NAMES CHEMICAL Name - MOST meaningful to the chemist- [the chemical constitution of the

drug and the exact placing of its atoms or molecular groupings]

GENERIC (NON – PROPRIETARY NAME)

COMMON NAME, PROPER NME- Is simpler than the chemical

name - It may be used in any country and

by any manufacturer- The 1st letter of the generic name

must NOT be CAPITALIZED

TRADEMARK, BRAND NAME, OR PROPRIETARY NAME

Is followed by the symbol ®.

This name is registered and the use is restricted to the owner of the drug

Are deliberately made easier to pronounce, spell and remember

The 1st letter of the Trade Name is CAPITALIZED

EXAMPLE

CHEMICAL NAME

GENERIC NAME

BRAND NAME

4 – thia – 1 azabicyclo [3.2.0]heptane – 2 – carboxylic acid, 6 [aminophenylacetyl)amino] – 3,3-dimethyl – 7 – oxo -, [2S- [2α-5α 6β (S*)]]-

ampicillin

Principen, Polycillin

PRESCRIBING, ADHERENCE AND INFORMATION ABOUT MEDICINE

DUTIES OF THE PRESCRIBER

The following are certain LEGAL requirements that must be met when a medicine is prescribed:

1. Name of the person whom the drug is prescribed , the address and the age

2. Drug name ( without abbreviation

3. Dose

4. Route of administration

5. Frequency of administration

6. Either the quantity to be supplied or the duration of therapy

7. Doctor’s name, address and signature

8. date

GENERIC PRESCRIBING ADVANTAGES

- It is likely to indicate the NATURE of the drug

- Dispensing is made easy

- Cheaper

DISADVANTAGES

- Can potentiate problems related to bioavailability

Common prescription abbreviationsac – before meals

ad lib – as much as desired

bid – twice daily

c – with

caps – capsules

et – and

Gtt , gtts – drop, drops

hs – at bed time

Od – right eye

Os – left eye

Ou – both eyes

pc – after meals

prn – as needed

q – every

qd – once daily

qid – 4 times daily

S – without

sig. – label

stat – at once

tid – thrice a day