Post on 12-Jan-2016
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Introduction to PharmacologyPHARM TECH
Pharmacology
Pharmacology is the science that deals with the study of therapeutic (beneficial) agents.
Knowledge of the properties of therapeutic agents is vital in providing quality health care.
It is an ever changing, growing body of information that continually demands greater amounts of time and education from health care workers.
What you will learn: Definition of pharmacology and its major subdivisions
Define a drug
Explain the differences between therapeutic effect, side effect, and toxic effect
Identify a drug receptor
Trace the interactions between agonists and antagonists with the receptors
Explain the relationship between drug dosage, drug response, and time
Explain drug safety and therapeutic index
Describe three names by which drugs are known
List two common drug reference books
Doctors and Pharmacists
How do physicians and pharmacists keep track of the medicine that exists from year to year? Physicians’ Desk Reference (PDR)-reference
most widely used by physicians, pharmacists, and nurses.
Updated yearly Provides information on indications for use,
dosage and administration, contraindications, and adverse reactions
Terms Used in Pharmacology Pharmacodynamics -- study of the action of drugs on
living tissue Pharmacokinetics -- study of the process of drug
absorption, distribution, metabolism, and excretion Pharmacotherapeutics -- study of the use of drugs in
the treatment of disease Pharmacy -- science of preparing and dispensing
medication Posology -- study of the amount of drug required to
produce therapeutic effects Toxicology -- study of the harmful effects of drugs on
living tissue
Drug
General definition -- any substance that can cause a change in function when administered to a living organism
Pharmacologically -- any medication that is used in treating a disease or disorder.
Drug sources -- natural sources, plants, etc.
Drug Effects Therapeutic effect – intended effect. Side effects – are not necessarily harmful. They may
have undesired effects. Adverse effects-may be harmful. With prolonged use
may effect function of vital organs, e.g., liver and kidneys. Reduction of dosage or switching to other drug may minimize harmful consequences
Toxic effects – all drugs will act as poison when taken in excess (drug poisoning). Effects are extremely harmful and sometimes even life threatening. The drug must be stopped and occasionally supportive treatment and administration of antidotes (remedy) may be required.
Terms Appropriate to Any Drug Site of action – is unknown for some drugs but determined for
most Mechanism of Action – how the drug produces its effects Lower receptor site – specific location on certain cells; similar to
a lock and key concept Agonists and antagonists-the chemical substances can alter a
drug’s action either by facilitating (helping) or interfering with such as delaying or obstructing its use.
Dose -the exact amount of a drug administered in order to produce a specific effect. ie. 1000mg of Acetaminophen for pain relief
Potency – a measure of strength or concentration of a drug to produce a specific effect. ie. Benadryl Liquid 12.5mg/5ml
Response Time of a Drug Response -the effect of the drug on the site of action.
3 ways to label the response:
1. response proportional (compared) to amount of drug given
2. maximal response achieved also known as the ceiling effect
3. Dose response that is above the ceiling effect. These are likely to produce toxic effects (overdose).
ED50-A dose that produces ½ the maximal response, referred to as (effective dose 50)
Onset of action – the time from drug administration to the first observable effect. The response will continue as long as effective concentration of drug remains at site of action.
Drug References
1. Pharmacopoeia/National Formulary (USP/NF)The official drug list recognized by U.S.
government Provides information concerning physical and
chemical properties of drugs Revised every 5 years Used primarily by drug manufacturers to ensure
drug production according to government standards.
Drug References
3. Physicians’ Desk Reference (PDR)-See slide 4 Reference most widely used by physicians,
pharmacists, and nurses.
4. Drugs Facts and Comparisons available in bound format and, most frequently
used, loose leaf form index and drug information service subscribed to
by most medical libraries updated monthly provides most current drug information on a
regular basis
Drug References
5. United Sates Pharmacopoeia Dispensing Information (USP DI)
United States Pharmacopoeia Convention, Inc. publishes series of volumes under general title
updated yearly Volume I: Drug Information for the Health Care
Professional -- provides in-depth information about prescription and OTC medications and nutritional supplements
Volume II: Advice for the Patient -- provides drug information for the patient, e.g., how to take, signs to watch out for, etc.
Drug References
6. Drug Monograph (profile or an insert)
An instrument that provides information prescription, over-the-counter (OTC), investigational, nutritional and herbal products.
Provides the important data about the drug.
All manufacturers’ monographs provide essentially the same items of information about each drug:
description
action
indications
usage in pregnancy
adverse reactions
dosages (and administration)
packaging availability