Ch.2 Principles Of Drug Action Flashcards
What are the 3 phases of drug actions
- Drug administration: drug is made available to body*
- Pharmacokinetics: what body does to drug
3.pharmacodynamics: what drug does to body
What are the Routes of Administration (Drugs portal entry)
- Enteral: absorption along GI (Tablet)
- Parenteral: besides the intestine( IV)
- Transdermal: to the skin (patch)
- Inhalation: (Gas, aerosol)
- Topical: to skin or mucous membrane ( lotion, ointment)
What are some positive drug interactions
- Synergism
- Additivity
- Potentiation
Synergism [ positive drug interaction]
Two drugs act on a target organ by different mechanisms
Additivity [ positive drug interaction]
What two drugs act on the same receptors for maximal effect
Potentiation [ Positive drug interaction]
Special case of synergism, one drug has no effect but can increase the activity of the other drug
What are some drug responsiveness terms
-Idiosyncratic effect
- Hypersensitivity
- Tolerance
- Tachyphylaxis
Idiosyncratic effect ( drug response)
Opposite of, or unusual, or an absence of effect
Hypersensitivity ( drug response)
Allergic or immune mediated
Tolerance (drug response)
Decreased intensity of response
Tachyphylaxis (drug response)
Rapid decrease in response to a drug
Potency vs. maximal effect
When a drug has a lower dosage but a high effect
Therapeutic Index (TI)
Difference between minimal therapeutic and toxic concentration of a drug ( smaller the difference, greater the risk)
Antagonist and agonist
Binds and initiate( agonist) or bind and cause no response (antagonist)
Drug interactions
Chemical, functional or competitive antagonism
What are the 4 factors increasing the L/T ratio
- Efficiency
- Inhaled drugs with high first-pass metabolism
- Mouth washing, rinse and spit
- Use of reservoir device
What is L/T ratio and what’s the formula
Proportion of drug made available from the lung, out of the total systemic available drug. Higher the ratio, more aerosol delivered to drug
(Lung does)/(lung dose + GI dose)
What is plasma half time (T 1/2)
A measure of how quickly a drug is eliminated from body
What does kidneys do to drugs
Kidneys are the primary site of drug excretion
What does liver does to a drug
Liver is primary site of drug metabolism
