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