Pharm Flashcards
Pharmacokinetics
absorption, distribution, metabolism, and excretion of drugs
Oral drugs
taken by mouth
come in tablets, capsules, powder, and liquid
EC
entericcoated drugs
dissolve when drug reaches the stomach
ER
Extended release
release over a period of time
XL
extended release
SR/XR
Sustained release
SA
Sustained action
What are the phases of pharmacokinetics?
Absorption, Distribution, Metabolism, and Excretion
Absorption
transmission of medications from the location of administration, to the bloodstream
Distribution
transportation of medications to sites of action by bodily fluids
Metabolism
changes medications into less active or inactive forms by the action of enzymes
Excretion
The elimination of medication from the body primarily from the kidneys
Different areas of location administration
GI tract, muscle, skin, mucous membranes, subQ tissue
Barriers to absorption (Oral)
medications must pass through the layer of epithelial cells that line the GI tract
Absorption pattern (Oral) varies due to:
GI pH and emptying time
Stability and solubility of medication
Presence of food in the stomach
Other concurrent medications
Forms of medications
Barriers of absorption (sublingual/buccal)
swallowing before dissolution allows gastric pH to inactivate the medication
Absorption pattern (sublingual/buccal)
quick absorption systemically through highly vascular mucous membranes
Barriers of absorption (rectal, vagina)
presence of stool in the rectum or infectious material in the vagina limits tissue contact
Absorption pattern (rectal, vagina)
easy absorption with both local and systemic effects
Barriers of absorption (inhalation by mouth or nose)
inspiratory effort
Absorption patterns (inhalation by mouth or nose)
rapid absorption through alveolar capillary networks
Barries to absorption (intradermal)
close proximity of epidermal cells
Absorption pattern (intradermal)
Slow, gradual absorption
Effects are primarily local
Barriers to absorption (subQ, intramuscular)
Capillary walls have large spaces between cells therefore having no significant barrier
Absorption pattern (subQ, intramuscular)
highly soluble meds have rapid absorption(10-30min), poorly soluble meds have slow absorption
sites with high blood perfusion have rapid absorption, sites with low perfusion have low absorption
Barriers to absorption (intravenous)
no barriers
Absorption pattern (intravenous)
immediate: enters directly into the blood
Complete: reaches the blood in its entirety
Factors influencing distribution
Circulation, permeability of the cell membrane, plasma protein building
Circulation
Diseases such as peripheral vascular or cardiac disease can delay medication distribution
Permeability of the cell membrane
medication must be able to pass through tissues and membranes to reach its target area.
Plasma protein building
Ability of medication to bind to a protein can affect how much of the medication will leave and travel to target issues. When two medications fight for the same protein it can cause toxicity
9 body systems
Neurological
Musculoskeletal
Respiratory
Cardiovascular
Hematologic
Gastrointestinal
Reproductive and Genitourinary
Endocrine
Immune
Parenteral (Injectable) Drugs
Come in liquid form or powder that needs liquid added (reconstitution)
Can be administered intravenously, subQ, intramuscular
Topical or Transdermal Drugs
Medications that are applied to the skin, eyes, ears, nose, rectum, vagina, or lungs
Drug Half-Life
time it takes for a drug that enters the body to decrease in amount by half
Onset
amount of time it takes for the drug to demonstrate a therapeutic response
Peak
time it takes the drug to demonstrate its full therapeutic effect (highest level)
Duration
length of time the drug’s therapeutic effect lasts without additional doses
Trough
when the drug is at its lowest level in the body
Trough
when the drug is at its lowest level in the body
Pharmacodynamics
biochemical changes that occur in the body as a result of taking a drug
Therapeutic effects
intended effects of the drug
