Clinical Pharmacology Flashcards
Define drug
External substance that acts on a living tissue to produce a measurable change in the function of that tissue
Give examples of drug use in dentistry
- L.A
- antimicrobials
- anxiolytics
- analgesics
What are symptoms of hyperthyroidism?
- rapid metabolism
- high pulse rate
- sweating and heat intolerance
- anxiety and agitation
- weight loss
What symptoms are shown with hypothyroidism?
- cold intolerance
- coarse skin
- memory loss
- slow pulse
- slow metabolism
give examples of autonomic drugs?
- adrenaline: beta agonist
- atenolol: beta blocker
- pilocarpine: cholinergic agonist
- atropine: cholinergic blocker
Define topical drug
drug applied to the tissue where it acts
define systemic drug
drug applied to the whole organism
define parenteral drug
drug administered by injection
define transdermal drug
drug applied to the skin for adsorption
define subcutaneous drug
drug injection into the tissues of the skin
define intramuscular drug
drug injected into muscle
define intravenos drug
drug injected into a vein
define transmucosal drug
drug applied to the mucosa for adsorption
give examples of acute toxic reactions in response to drug administration
- bone marow suppression
- hepatoxicity and biliary stasis
- acute nephrotoxicity
give exmaples of drug-drug interaction alterations due to drug administration
- protein binding eg. warfarin and aspirin/NSAIDs
- drug metabolism eg. warfarm, simvastatin
what are the 8 elements a prescription must include?
- patients name, address age
- patient identifier: DoB, CHI number
- number of days of treatment
- drug to be prescribed
- drug formulation and dosage
- instructions on quantity to be dispensed
- instructions to be given to the patient
- signed: idenitifier of prescriber
what are the 4 main modes of drug action?
- receptors
- enzyme function
- ion channels
- trasnport systems
What may drug-receptor interactions be coupled to?
- G-proteins
- ion channels
- enzymes
- gene transcription
what is drug response determined by?
drug-receptor interaction
- affinity
- occupancy
drug induced response
- efficacy
Define affinity
the tightness of the drug binding to the receptor
define occupancy
how much time the drug spends on the receptor
define efficacy
how effective the drrug is at producing a response from the receptors
What is an agonist?
bind to a receptor and cause an effect
what is the difference between an agonist and a partial agonist?
- more difficult to prduce drug/receptor effect than with agonist
- increasing PA may improve efficacy for some
give an example of an irreversible antagonist
phenoxybenzamine - alpha 1 blocker
give an example of a reversible antagonist
atenolol - beta 1 blocker
give an example of a drug that acts on ion channels
- LA
- anti-diabetic drugs
What are the 6 stages of drugs in the body?
- administration
- absorption
- transport
- clinical effect
- metabolism
- excretion
What is first pass metabolism?
drug has to pass through the liver to reach systemic circulation therefore drug action may be altered by state of liver function.
what are the various routes of drug administration?
- oral
- intravenous/intramuscular
- transdermal/subcutaneous
- transmucosal
- inhalation
what are the adv and dis of oral administration
adv
- socially acceptable
- drug formulation can change onset and duration of action
dis
- slow onset
- variable absorption
- first pass metabolism
what are the adv and dis of intravenous/intramuscular drug administration?
adv.
- rapid onsen
- predictable plasma levels
- no first pass
dis.
- allergic reactions more sever
- short duration of action
- access difficulties/self-medication
- more expensive
what are the adv and dis. of transdermal/subcutaneous drug administration?
adv.
- no first pass
- allergic reactions often localised
- prolonged reaction
dis.
- very slow onset
- self-medication possible
- more expensive
- effects vary
Define bioavailability of a drug
proportion of an ingested drug that is available for clinical effect
how is a drug transported?
- dissolved in blood and trasnported by plasma proteins (usually albumin)
- bound drug: inactive
- speed of diffusion into tissues from blood depend on blood flow to area, blood wall vessel barrier, active secretion of drug into the tissue
what is the single compartment model?
drug behaves as if its evenly distrubuted throughout the body
what is the two-comparment model?
drug behaves as if it is in equilibrium with different tissues in the body
Give examples of phase 1 metabolism reactions
- oxidation
- reduction
- hydrolysis
give examples of phase 2 metabolism reactions
- glucoronidation
- sulphation
- methylation
- acetylation
what is the function of drug metabolism?
to prepare the drug for elimination from the body
where are drugs mainly metabolised?
liver
(some in plasma)
where does majority of drug excretion occur?
- renal excretion of water soluble metabolites (urine)
- liver (bile)
- lungs (inhaled gases and volatile fractions of other drugs)
which organ fucntions determines dosage of drug?
liver and renal
what is plasma half-life?
time taked to eliminate half of drug
what is first order kinetics
drug metabolism is directly proportional to drug concentration
excretion: passive diffusion only
what is zero order kinetics?
drug metabolism occurs at a fixed rate and is independent from drug conc
excretion: active process
what occurs if drug dosage is too frequent?
plasma levels become toxic
what occurs if drug dosage is too infrequent?
results in sub-therapeutic plasma levels and no clincial effect
what is pharmacokinetics and pharmacodynamics?
study of drug interaction with the body and the body interaction with the drug
