What is the definition of drug administration
how drugs are delivered to the body
what are the 3 different dosage forms for bronchodilators
Routes of administration:
enteral
-Absorption anywhere along the gastrointestinal tract
*mouth , stomach.intestines
-Referred to as “small intestine” because most drug absorption occurs there
route of adminstration:
parenteral
injection:
-Intravenous (IV)- vein
-Intramuscular (IM)-deep muscle
-Subcutaneous (SC)- beneath epidermis/dermis
-Intrathecal (IT)- spinal cord
-Intraosseous (IO)- bone marrow
route of administration:
transdermal
-Application to skin
-Long term continue delivery
route of administration:
inhalation
-rapid delivery to the lungs via gas, aerosolized agents
route of administration:
topical
-applied directly to skin or mucus membrane
define pharmacokinetics
what the body does to the drug
*absorption, distribution, metabolism, elimination
define pharmacodynamics
what the drug does to the body
define pharmacogenetics
variation in patient response to drugs due to hereditary differences
define structure activity relationship
relationship between a drug chemical structure and outcome it has on the body
define tolerance
decreasing intensity of response to a drug over time
when a medication is given orally for systemic effect a pill must first_____ to liberate the active ingredient
dissolve
what are the 4 major body compartments? which one has the least? in what units of measurement are they measured?
-vascular (blood) —-5L * least
-interstitial fluid—–10L
-intracellular fluid—20L
-fat(adipose tissue)-14-25L
what are the 4 factors that effect drug absorption
- route of administration
2.metabolic degradation
3.inactivation by stomach acid - blood flow to absorption site
what organ is the primary site of drug metabolism
liver
what organ is responsible for drug excretion
kidneys
describe the first-pass effect
medication taken orally→stomach or intestine→transported via portal vein(blood)–> liver (metabolizes drug, *reducing concentration of drug)→right/left hepatic vein→inferior vena cava
*drugs taken orally=little drug reaching systemic circulation
routes of administration avoid the first pass effect
-Intravenous
-Rectal
-Subcutaneous
-Intramuscular
-Inhaled
-Sublingual
-Buccal
-Aural
-Intra arterial
-Intranasal
-Intraocular
-Intravaginal
-Intrarticular
approximately what percentage of an inhaled aerosol reaches the lower respiratory tract with current delivery devices?
10-30%
provide examples of two topical administration of drug
-corticosteroid cream-contact dermatitus
-eye drops- glaucoma
define the L/T ratio
-Amount of drug that is made available to the lung out of the total available to the body.
what can we do as respiratory therapist to increase the L/T ratio
-efficient delivery devices
-inhaled drugs with high first-pass metabolism
-mouth washing, rinsing, spitting after inhalation
-use of reservoir device
what are the 4 mechanisms for transmembrane signaling?
-aqueous diffusion
-lipid diffusion
-carrier-meditated transport
-pinocytosis
