Chapter 1 - Intro Flashcards
Pharmacology
Study of medicines
Modern pharmacology is thought to have begun in the
- early 1800s
- chemists were making progress in separating specific substances from complex mixtures
- Isolate active ingredients such as morphine, cocaine, ect.
Pharmacology officially recognized as discipline when
The fist department of Pharmacology was established in Estonia in 1847.
John Jacob Abel
Considered the father of American pharmacology founded the first pharmacology department in the US at the University of Michigan in 1890.
Pharmacology 20th century
Pace of change exponential
- no longer had to isolate active ingredients but could synthesize
- 100s of new drugs
- possible to understand how drugs produced their effects right down to the molecular mechanism of action
Drug
Any substance that is taken to prevent, cure or reduce symptoms of a medical condition.
- Food is not a drug
- Substances normally found in the body are not considered drugs unless they are administered to treat a condition
Pharmacotherapy
- Or pharmacotherapeutics is the application of drugs for the purpose of disease prevention and treatment of suffering
- Critical intervention for many conditions
Ideal Drug Properties
- Effectiveness - FDA requires all new drugs must be proven effective prior to release. Essential property.
- Safety - does not produce adverse effects; HR at high doses for prolonged time. ADR can’t be eliminated, but reduced with proper selection and dosing
- Selectivity - elicits only intended response; unfortunately all drugs have side effects
Additional Ideal Drug Properties
Reversible Action - often prefer to decrease with time
Produced rapid, predictable response at low dose
Ease of Administration - enhance adherence, decrease risk (infections r/t injections)
Can infrequently be taken ex. once a day
Freedom from Drug Interactions - few don’t interact
Low Cost - substantial financial burden will decrease use
Chemical Stability - retain activity indefinitely
Simple Generic Name - easy to recall and pronounce
Is quickly eliminated from the body after it has its desired effect
– The reality is there is no such thing as a perfect drug
Indications
- Conditions for which a drug is approved
- Every drug has at least one
- Most have multiple
Unlabeled or off-label indications
when drugs are used for conditions that they have not been approved for
Classifications of drugs
The US Food and drugs administration (FDA) lists over 11,000 approved drugs
- Two basic classifications: therapeutic or pharmacological classification
- Categories used for prescription and nonprescription drugs
- Therapeutic classification - What is being treated. Ex. antidepressants, antihypertensive
- Pharmacologic classification - How the drug acts. Ex. vasodilator, diuretic
Many drugs have multiple classifications
Prototype Drugs
- Select a single drug from a class and compare all other medications in the class to this representative medication.
- Can predict the actions and adverse effects of other drugs within that class.
-Helps with learning pharmacology - Selecting a prototype drug is not always a simple matter as there can be disagreement.
- The traditional approach uses the oldest and best understood drug, but sometimes a new drug is developed that is more effective - This textbook uses a practical approach - selecting a combination of radiation drugs and those widely used.
Types of names for drugs
- Chemical
- Generic
- Trade
Chemical name
- Assigned using standard nomenclature established by the International Union of Pure and Applied Chemistry (IUPAC)
- Each drug has one chemical name
- clear and concise
- complicated and difficult to remember
Generic name
- Assigned by United States Adopted Name Council
- Less complicated than chemical names
- Easiest to remember
- Many organizations use generic names to describe and identify
- Easy for students to memorize one name
Trade name
- Named by pharmaceutical company marketing drug. Brand or product name
- Attempt to be short and easy to remember
- Proprietary - own patent, allows monetary benefit from investing in drug research
Exclusivity
For a certain # of years, competing companies are not allowed to market generic versions of a new drug
- Typically 5
- Can be extended 3 years if the drug is determined to have a new indication, can be delivered by a different route or is made available in a different dosage form.
- Pharmaceutical companies market trade-name drugs
- Claim significant difference between trade-name and generic
- Consumer advocates argue generic should be available
- Cost difference between generic and trade-name can be significant
Combination drugs
More than one active generic ingredient
- Issue when trying to match one generic name with one product name
- Generic names should be used when naming the active ingredients in combination drugs
- Common to write the generic name in lowercase first, followed by the trade name in parenthesis with the first letter capitalized
- Ex. alprazolam (Xanax), acetaminophen (Tylenol)
Generic drugs
Less expensive, but may differ in bioavailibility.
Substituting with Generics
- Laws vary by state
- Pharmacists may substitute generic for brand
- Pharmacists may have to obtain approval from provider before substituting generic
Nine out of every 10 prescriptions dispensed in the United States are for generic drugs. The greatest cost savings are for generic drugs prescribed for mental health indications and hypertension (Generic Pharmaceutical Association, 2015).
Bioavailability
- Rate and extent to which the active ingredients are absorbed from a drug product and then available at the site of action
- May be a difference between trade and generic
- Affected by many factors including inert ingredients and tablet compression. Anything that impacts absorption or travel to target cells.
Bioequivalent
When the trade and generic drug have the same rate of absorption and same onset of therapeutic action.
Biologic drugs
Medications made by living cells such as bacteria or yeast.
- Often complete requiring many years of research to gain FDA approval
- Thus expensive
Biosimilar drugs
Comparable effectiveness to biologic, but not exactly the same.
- Do not require the same rigorous testing
- Thus, less expensive
- Most just need to demonstrate to the FDA that the drug differs very little from the approved reference product with the same route, dosage and mechanism of action.
Intensity of Drug Response
Administration - right patient, medication, dose, route, time. Also right documentation, education, right to refuse, right assessment and right evaluation.
Avoid errors leading to too high, low or wrong medication
Individual Variation - depends on several factors including age, gender, weight, kidney and liver function, genetic factors
