Pharmacology Flashcards
What is goal of pharmacology?
Prescribe appropriate meds for patient’s needs.
Medication delivered to site of action.
Elicit and appropriate clinical response.
What are types of drug administration?
Parenteral, enteral,
What are categories of parenteral drug administration?
Injection, intravenous, intramuscular, subcutaneous, intrathecal, sublingual, inhalational
What are characteristics of parental administration?
No GI absorption, fast acting, high concentration of drug quickly, valuable during emergency, pain at injection site,
Which parental administrations has quick delivery?
Inhalation: quick delivery to bronchi or alveoli for local effect.
Gaseous anesthetic, vaporizes quickly
Which type of drug administration is convenient, most common, effective absorption, and is the most economical?
Enteral by mouth (p.o.)- tablets, capsules, sustained release, chewable, liquid
What are effects of rectal administration?
Local or systemic effects, effective if GI tract is upset
What are effects of transdermal administration?
Slowly absorbed, prolongs blood levels
What are different terms for pharmokinetics?
Bioavailability Distribution Clearance Half-life Dosage Administered
What is bioavailability?
Route of administration with goal of getting into bloodstream.
IM, sublingual, by mouth, or transdermal
What is definition for distribution?
Drug passes through body via circulatory system
General or restricted: depends on permeability, drugs bind to proteins but now drug unavailable to bind to receptor site
What is clearance and what accomplishes it?
Rate of elimination by all routes relative to concentration of drug in biological fluid.
Kidneys are most important route for clearance.
Inadequate body system or circulatory system may hamper clearance: drug toxicity
What is half-life?
Time needed for drug to be reduced by 50% in plasma concentration.
The length of time the effects of drug will last.
Medications taken at regular intervals
T/F: the longer the half life, the longer effect of drugs?
True
Who determines dosage?
Physician
What must be considered with dosage of drugs?
Amount to be administered at one time.
Route of administration
Interval between doses
Period of time over which drug administration is to be continued
What are characteristics of pharmacokinetics: administered?
Continuous input: sustained release, IV, subcutaneous
Intermittent doses: meds given at certain times during day
What are parts of pharmacodynamics?
Drugs don't have isolated effects on tissues. Digitalis and generalized effects. Selectivity Agonist vs antagonist Receptors Autonomic nervous system
How can drugs effect tissue?
Can affect any receptor specific to drug’s structure.
Person’s tolerance to drug is related to drug’s primary effect, secondary effects, or side effects
What does digitalis do?
Works at sodium potassium pump.
Primary target is AV node (decrease conduction)
Increased myocardial activity
Affects blood chemistry: hypokalemia
What is drug selectivity?
Certain concentrations of drug exists, drug is preferentially attracted on one group of receptors.
Atenolol targets B1 receptors
Propanolol targets B1 and B2 (non selective)
T/F: atenolol targets B2 receptors?
False: targets B1
What does propranolol target?
B1 and B2 receptors (non selective)
What are pharmacodynamics of the autonomic nervous system?
Cholinergic (PNS)
Adrenergic (SNS): alpha and beta receptors sensitive to catecholamines, epinephrine in adrenal medulla, norepinephrine in local level from sympathetic postganglionic fibers
What are goals of medical management of cardiopulmonary disease?
Acute vs long term treatment of CAD and symptoms
Treatment directed toward preventing myocardial ischemia and infarction
Want to maximize and improve existing cardiac function
What are nitrates used to treat?
Angina symptoms from myocardial ischemia.
Heart failure, acute MI, HTN
How do nitrates work?
They vasodilate by relaxing smooth muscle in coronary and peripheral arteries, veins, bronchioles, GI tract, and uterus
What does the vasodilation result in (nitrates)?
Peripheral vasodilation results in venous pooling, decreased venous return to heart (decreased preload).
Decreased preload reduces ventricular dimensions and diastolic filling pressures.
Decreased resistance decreases afterload
What is result of decreased afterload (nitrates)?
Reduces myocardial demand
Relieves or delays onset of angina
What are contraindications and side effects for nitrates?
Reflex tachycardia, orthostatic hypotension, flushing headache
What is effect of nitrates on exercise in CAD?
Nitrates prior to exercise reduces cardiac workload and improves exercise performance.
Increased tolerance for activity before onset of angina pain
What must we as PTs consider when our patient is on nitrates?
Obtain BP before they take them.
Have them lie down before administration.
If pain not relieved by 3 doses of nitro (one tablet every 5 minutes) call 911
T/F: if chest pain is not relieved in your patient after 3 doses of nitro tell them to take another one.
False: call 911 if in home health, if in hospital activate protocol,
T/F: beta blockers reduce myocardial oxygen requirements
True
What is primary mechanism for beta blockers?
Responsible for diminishing actions of SNS (catecholamine release) on beta receptors
How do beta blockers reduce myocardial oxygen requirements?
Decrease HR, BP, myocardial contractility (rest and exercise).
Decreased HR= prolong diastole (increased blood supply to myocardium)
What are the steps of beta blocker drugs effects?
Compete with catecholamines for beta receptor sites in heart and other tissues
Causes inhibition of adrenergic stimuli to Beta 1 and Beta 2 receptor sites
Where are beta 1 found? Where are beta 2 found?
1: found in heart. Inhibition decreases HR, conduction through AV node, decrease contractility
2: found in periphery, lungs, and body. Inhibition causes bronchoconstriction, vasoconstriction of vessel beds
What normally happens at beta receptor sites?
Catecholamines bind with beta receptors sites
Which initiates responses to SNS adrenergic stimulation