PHARMACOLOGY PART 3 Flashcards
the method by which
a drug dose is made available to the body
Drug administration:
physical state of the drug
in association with nondrug components
ex: Tabs, caps, injectables
Drug Dosage Forms-
is the portal of
entry for the drug into the body
ex: oral(enteral, injection, or inhalation
The route of administration
active ingredient
drug
gelatinous material that allows
drug to be swallowed
capsule
Preservatives, propellants for MDI, dispersants
(surfactants) and carrier agents with DPI
Aerosol agents
refers literally to the small
intestines
more broadly applicable to administration of
drugs intended for absorption anywhere along
the GIT
enteral
most common route bec it is convenient,
painless and offers flexibility in possible
mouth
means beside the intestines
parental
bolus or steady infusion
Intravenous(IV)
injected deep into the
skeletal muscle
Intramuscular (IM)
gases and aerosolized agents
Inhalational-
skin, eyes, nasal drops
Topical
What are the 5 routes of administration?
Enteral, Parental, Transdermal, Inhalational,Topical
The time course and disposition of drug in the body. Absorption, metabolism, and elimination
Pharmacokinetics
The drug will go into the blood stream that will be transport all throughout the body
systemic effect
This can lead to unwanted effects
local effect
describes what the body to to the drugs
Pharmacokinetics
describes what the drug does to the body
pharmacodynamics
4 absorption in pharmacokinetic phase
Aqueous Diffusion
Lipid Diffusion
Carrier-mediated Transport
Pinocytosis
factors affecting absorption
Route of administration
Bioavailability- is used to indicate the proportion
of a drug that reaches the systemic circulation
Blood flow to the site of absorption
is used to indicate the proportion
of a drug that reaches the systemic circulation
bioavailability
is the process by which a
drug is transported to its site of
action, eliminated, or stored.
distribution
primary site of drug metabolism
and biotransformation
liver
Liver contains ____ that
convert lipophilic(lipid-soluble) drug
molecule into water-soluble metabolites
that are more easily excreted.
intracellular enzymes
major enzyme system in the liver
cytochrome P450
Rifampin can induce _____ and increase the metabolism of several drugs, including warfarin
and oral contraceptives
CYP enzymes
cigarette smoking can
increase the breakdown of _____ in patients with
chronic lung disease, shortening the half-life of the drug
from approximately ______
theophylline
7.0 to 4.3 hours
The primary site of drug excretion in the body is the
is important for removing drug metabolites
produced by the live
kidney
site of much drug metabolism
liver
is a measure of the ability of the body
to rid itself of a drug. Most often, is expressed as
total systemic or plasma clearance to emphasize that all of the
various mechanisms by which a given drug is cleared (e.g.,
metabolism, excretion) are taken into account.
clearance
refers to a hypothetical volume of
plasma that is completely cleared of all drug over a given
period. Consequently, Clp is usually expressed as liters per
hour (L/hr) or, if body weight is taken into account, liters
per hour per kilogram
PLASMA CLEARANCE
To achieve a steady level of drug in the body, dosing must
equal the rate of elimination:
Dosing rate (mg/hr) (CIP)(L/hr) ×
plasma concentration mg/L)
mAINTENANCE DOSE
(T1⁄2) (the time required for the plasma
concentration of a drug to decrease by one-half) is a measure of how quickly a drug is eliminated from the body.
Plasma half life
The first-pass metabolism of three common inhaled aerosol drugs is a
Albuterol: 50%
* Budesonide: 90%
* Terbutaline: 90%
plasma half life of common drugs
Acetaminophen 2
Amoxicillin 1.7
Azithromycin 40
Digoxin 39
Gabapentin 6.5
Morphine 1.9
Paroxetine 17
Terbutaline 14
is exemplified by a
nasally inhaled vasoconstricting agent (decongestant), such
as oxymetazoline (Afrin), or by an inhaled bronchodilator
aerosol, such as albuterol (Proventil-HFA, Ventolin-HFA,
Proair HFA), to dilate the lower airways.
local effect
exemplified by the administration of inhaled
zanamivir (Relenza) to treat influenza, inhaled morphine
for pain control, or inhaled insulin aerosol for systemic
control of diabetes.2
systemic effect
s used in the treatment of respiratory diseases
such as asthma, chronic obstructive pulmonary disease, or
cystic fibrosis are intended for a local, targeted effect in the
lung and airway
inhaled aerosols
y. The traditional percentages given
for stomach and airway proportions, based on Newman’s is
90% (stomach) and 10% (airway)
Approximately —— of the drug impacts in the
mouth or oropharynx and contributes to the 90% reaching
the stomach
50% to 60%
Lung deposition with an inhaled —–, has been reported as 15%
with a pressurized MDI (pMDI) and 32% with a—–
corticosteroid, budesonide (Pulmicort)
DPI (Pulmicort Turbuhaler; AstraZeneca, Wilmington, Delawar
It is thought that aerosol drugs interact
with the site of action in the airway: secretions in the lumen, nerve endings, cells (e.g., mast cells), or bronchial
smooth muscle in the airway wall
inhaled portion
Factors Increasing Lung Availability/
Total Systemic Availability (L/T) Ratio
with Inhaled Drugs
- Efficient delivery devices (high airway and low gastrointestinal
delivery) - Inhaled drugs with high first-pass metabolism
- Mouthwashing, including rinsing and spitting
- Use of a reservoir device (spacer, holding chamber) to decrease oropharyngeal deposition and swallowed drug amount
Using an MDI, approximately— of the inhaled drug reaches the lung,
with — going to the stomach. With complete absorption
from the stomach, half of this 70% is broken down in the
liver, so that — reaches the systemic circulation. The total amount of the original 100% dose reaching the circulation is —- (lung, 30%; stomach and liver, 35%). Because
30% of the 65% comes from the lung, this gives an L/T
ratio of 30/65 $
30%,70%,35%, 65%,0.46.
describes the mechanism of activity by
which drugs cause their effects in the body. The principal
concept is the drug target protein (e.g., drug receptor).
pharmacodynamics
are any cell component that combines with a drug to change or enhance the function of the
cell
receptor
The relationship between the
chemical structure of a drug and its clinical effect or activity
is termed the
structure-activity relationship (SAR).
MEASURE OF HOW QUICLY THE DRUG IS ELIMINATED FORM THE BODY
PLASMA CLEARANCE
