(B) PRINCIPLES AND ADMINISTRATION OF DRUG - PHARMA Flashcards
➢ Study of how a patient genome affect his/her response to medications
➢ Study of the variability in drug response due to heredity
PHARMACOGENETICS
- is the science of drug action on
biological system - Embraces knowledge of the sources,
chemical properties, & biological effects
& therapeutic use of drugs. - Study of the nature, actions & uses of
drugs.
PHARMACOLOGY
interaction of drugs with
biochemical (what the drug does to the body)
PHARMACODYNAMICS
how the body absorbs,
distributed, metabolized & eliminated the drug (what
body does to the drug)
PHARMACOKINETICS
how is the medication absorbed
❖ First-pass effect
❖ Bioavailability
ABSORPTION
how does it spread through the
organism?
DISTRIBUTION
- is the medication converted
chemically inside the body, & into which
substances.
METABOLISM
- how is the medication eliminated
EXCRETION
Percentage of administered drug available for activity
BIOAVAILABILITY
the chemical component
responsible for the claimed therapeutic effect of the
pharmaceutical product.
ACTIVE INGREDIENT
the description of the chemical
structure of the drug or medicine & serves as the
complete identification of a compound.
CHEMICAL NAME
- the finished product form that
contains active ingredients, generally but not
necessarily in association w inactive ingredients.
DRUG PRODUCT
drugstores, pharmacies & any other
business establishments that sells drugs or
medicines.
DRUG OUTLETS
- a list of drugs that meets the health care
needs of the majority of the population
CORE LIST
the proprietary name given by the
manufacturer to distinguish its product from those
competitors.
BRAND NAME
- gives direction to
the PT of taking the drug
Sig. (Sigma - let it be labeled)
expiry date indicated on the
packaging.
EXPIRY ON DRUG
2 GROUPS OF MEDICATIONS
- OVER THE COUNTER (OTC)
- PRESCRIPTION ON MEDICATION (POM)
the rate which a drug reaches
different organs & tissues. Equilibration is
rapidly achieved w heart, lungs, liver, kidneys &
brain where blood flow is high.
BLOOD FLOW
changes in pH occuring in
disease may also affect drug distribution.
EFFECTS OF PH
will affect the ability of the drug
to bind to plasma proteins & to cross lipid
membrane barriers.
LIPID SOLUBILITY
- the ability of a drug to
reach various tissues will depend on the
permeability of the capillaries at the site in
question.
CAPILLARY PERMEABILITY
a drug which causes a physiological
effect.
AGONIST
a drug which blocks the response
produced by an agonist.
ANTAGONIST
an agonist which produces a
maximal response by occupying all or a fraction
of receptors.
FULL AGONIST
an agonist which produces
less than a maximal response even when it
occupies all of the receptors
PARTIAL AGONIST
9 FORMS & ROUTES OF DRUG ADMINISTRATION
- TABLETS/CAPSULES
- LIQUIDS
- TRANSDERMAL
- TOPICAL
- SUPPOSITORIES
- NASOGASTRIC & GASTROSTOMY TUBES
- NOSE DROPS AND SPRAYS
- AEROSOLS (INHALATION)
- PARENTERAL
refers to the observation of a
maximal tissue response when only a fraction of
the total number of receptors are occupied.
SPARE RECEPTORS
- Oral medications are not given to clients who
are vomiting, lack of gag reflex & comatose. - Enteric coated & time release capsules must be
swallowed whole to be effective - Administer drug in an empty stomach if it
interferes w absorption - Drugs given sublingually remain in place until
fully absorbed.
TABLETS & CAPSULES
- Includes elixirs, emulsions & suspensions
- Requires refrigeration once reconstituted.
LIQUIDS
- This medication is stored in a patch placed on
the skin & absorbed through the skin, having
systemic effect. - It provide more consistent blood levels & avoid
GI absorption problems
TRANSDERMAL
- Can be applied to the skin in a number of ways
such as w a glove, tongue blade or applicator - Use appropriate technique to remove medication
from container & apply to clean, dry skin
TOPICAL
CAN BE RECTAL AND VAGINAL
SUPPOSITORIES
describes the drug’s chemical
structure & is used by the chemist
CHEMICAL NAME
are entering the intestinal tract
ENTERAL
➢ Given by mouth is the most common route of drug administration,
➢ With the most complicated pathway to the target tissues.
➢ Most drugs are absorbed in the intestinal tract by passive transfer and usually end up in the portal circulation
encountering the liver and thus high chance of passing the first-pass effect.
ORAL
➢ Usually, oral route
➢ _____________________ or also known as first-pass metabolism or pre-systemic metabolism
➢ Is when an administered drug enters the liver (portal circulation before entering the systemic circulation)
* Undergoes extensive biotransformation
* Decreasing the concentration rapidly before it reaches its target.
* Beneficial in some where inactive form becomes active (codeine to morphine)
FIRST-PASS EFFECT FEEDBACK
can be classified into parenteral as well,
➢ Does not enter the lower gastro-intestinal tract,
➢ It is placed under the tongue thus going oral.
➢ Drug diffuses into the capillary network and enters the system circulation directly
* very rapidly absorbed,
* low infection risk,
* avoiding the rough environment of the git and
* no first-pass metabolism.
SUBLINGUAL
➢ produce local or systemic effects
➢ quite unreliable
* 75% of drainage of the rectal region bypasses the portal circulation, minimizing first-pass effect.
* the inferior and middle rectal veins are linked to the systemic circulation whereas the superior rectal vein
joins the inferior mesenteric vein and from there onto the portal vein.
➢ It can be very useful during vomiting and in patients that are unable to take medications by mouth.
RECTAL
➢ This route of administration avoids the GIT
➢ used for drugs that are poorly absorbed or unstable in the GIT, for unconscious patients and when acute onset
is required.
PARENTERAL
➢ Injection straight into the systemic circulation is the most common parenteral route.
➢ It is the fastest and most certain and controlled way.
* It bypasses absorption barriers and first-pass metabolism (LIVER)
* It is used when a rapid effect is required, continuous administration and large volumes.
➢ The disadvantages are that one cannot recall injected drugs, introduction of bacteria through contamination
➢ Adverse effects: as well as too rapid delivery or too high concentration may produce strong adverse effects.
INTRAVENOUS (IV)
➢ Produces a faster effect than oral administration,
* rate of absorption depends greatly on the site of injection and on local blood flow.
➢ The drug can be aqueous solutions or depot preparations (in a form of ester or salt)
* The absorption of the aqueous is fast and the depot form is slow.
* The advantage of the depot form is that it can provide a sustained dose over an extend period of time.
INTRAMUSCULAR (IM)
➢ The absorption of _________ injections is slower than that of IV route
➢ it needs absorption similar to Intramuscular injection. However
➢ it minimizes the risks associated with IV injections.
SUBCUTANEOUS (SC)
➢ As the name implies, it is applied where and when a local effect of the drug is desired.
TOPICAL
➢ Use in gaseous drugs or those that can be dispersed in an aerosol,
➢ produces an effect almost as fast as with IV.
➢ provides rapid delivery across the mucous membranes of the respiratory tract.
➢ It is used for asthmatic drugs, and anesthetics.
INHALATION
➢ Drug administration directly into the nose.
➢ Includes agents such as nasal decongestants or cocaine by abusers.
INTRANASAL
➢ Drug administration through the skin. It can achieve systemic effects but rate of absorption can
vary markedly depending on the physical characteristics of the skin at application.
TRANSDERMAL
➢ Drug administration into the cerebrospinal fluid (CSF). Used in cases of CNS cancers, cryptococcal
meningitis etc.
INTRATHECAL/INTRAVENTRICULAR
➢ Deliver medicines in between the layers of the skin
➢ Used in skin testing
INTRADERMAL
➢ Drug administration through bone marrow
INTRAOSSEOUS
The length of time it takes for a medicine to start to work.
ONSET
LENGTH OF TIME THE DRUG EXERTS A THERAPEUTIC EFFECT
DURATION
Drug reaches highest concentration in the blood
PEAK
All drugs has ________________ (secondary effects), even in correct drug usage
* Predictable
* Inconvenient, to severe, to life threatening
* Desirable
SIDE EFFECTS
- Unintentional, unexpected that may occur in normal drug dosages
- Reactions maybe mild to severe including anaphylaxis (cardiovascular collapse)
- Always underible, must be reported so as to represent variances from planned therapy
ADVERSE REACTIONS
- Decrease response to a drug oer a course of therapy
TOLERANCE
- When drug level exceed the therapeutic range
- Secondary to overdosage (intentional or unintentional) or due to drug accumulation
- Factors: disease, genes, age
DRUG TOXICITY
- Response not attributed the chemical property of a drug
- Can be positive or negative
- Can be influenced by the beliefs, attitudes and expectations of the patients
- Can be psychological in origin but resulted to changes in heart rate, bp and pain sensation
PLACEBO EFFECT
Changes that occur in the absorption, distribution, metabolism and excretion of one or more drugs
PHARMACOKINETIC INTERACTION
when 2 drugs are administered in combination and the response increased beyond what either could
produce alone (desirable or undesirable)
▪ losartan plus hydrochlorthiazide
ADDITIVE DRUG EFFECTS
- when 2 or more drugs are given together, one drug can have a synergistic effect to another
- effect of 2 drugs given together is substantially greater that that of either drug alone
- decrease drug dosing of the other
▪ coamoxiclav (amox and clavunalic acid)
SYNERGISTIC DRUGS
- when drug with antagonizing effect area administered together, one drug reduces /block the effect of
the other/ can be beneficial or otherwise
▪ Ibuprofen plus famotidine
ANTAGONIST DRUG EFFECT
