Transcript RT101 Basic Therapeutics

RT 210 Pharmacology
Terminology
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Drug
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Exerts biological effect used for
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Treatment
Diagnosis
Prevention
Chemical name
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Chemical structure of the drug
Terminology
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Generic name
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Name given by US Pharmacopoeia
Trade name
Brand or patented name
Side effect: Other than desired effects
Half life: Length of time when 1/2
dosage is still active in the body
Terminology
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Tolerance: A condition in which the dose of a
drug must be increased (over time) to obtain the
desired effect -or- a decreasing intensity of
responsiveness to a drug over time
Tachyphylaxis: Rapidly developing tolerance to a
drug -or- a rapid decrease in responsiveness to a
drug.
Additive effects: The effect of two chemicals
acting simultaneously on the same receptors & is
the simple sum of the effects that they would have
if acting alone
Terminology
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Synergism: The presence of one
chemical that enhances the effects of the
second. Also, when 2 drugs act on a
target organ by different mechanisms of
action & the effect of the pair is greater
than the sum of the separate effects of
the drugs.
Terminology
POTENTIATION:
Special case of synergism in which one drug has no
effect, but can increase the activity of the other drug.
Also, the action of these two drugs result in the total
effect being greater than the sum of the independent
effects.
Terminology
Pharmaceutical phase: Method by which a
drug is delivered
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Inhalation (Benefits)
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Immediate onset of action at desired site
Reduced systemic side effects
Smaller doses required
Ability of patient to self administer
Pharmacokinetic phase: Time required for
drug absorption, distribution, metabolization,
and excretion
Terminology
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Pharmacodynamic phase: Mechanism of
action by which a drug causes its therapeutic
effect
Agonist: A substance that binds to a receptor
and triggers a response in the cell
Antagonist: A substance that binds to a
receptor but fails to activate the receptor and
actually blocks it from activation by agonists
Prescription requirements
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Patient name
Drug name
Dose
Frequency
Route of administration
Check before administering drug
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Chart for information
Patient's name band
Medication label
Dates of expiration or opening of the
drug
Dosage
Response to previous administration of
drug
Normal routes of administration
(fastest to slowest)
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IV (intravenous)
Inhaled (aerosol to lung)
IM (intramuscular)
Sub Q (subcutaneous injection)
Sublingual or rectal absorption
Oral
Topical
Concentration
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The concentration is the percent solution
of the active ingredient in the drug
It is the weight (in grams or mg) of
solute dissolved in a volume (in ml) of
solvent expressed as a percentage
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1% solution means that 1 gram (1000mg) of
solute is dissolved in 100 ml of solvent
1000 mg/100 ml = 10 mg/ml
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It is possible to determine the amount of
solute or solvent needed in a solution of
a known percentage
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Before you can determine the amount of
solute or solvent that is needed you must
first express the concentration as mg/ml
Multiply the percentage by 10
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i.e. 1% * 10 = 10 mg/ml
0.5% * 10 = 5 mg/ml
Determine what you are trying to find
Solute (mg) = solvent (ml) * concentration (mg/ml)
You have 1 ml of a 1% solution. How much solute do you need?
1% * 10 = 10 mg/ml
Y mg = 1 ml * 10 mg/ml
Y mg = 10 mg
Solvent (ml) = solute (mg) ÷ concentration (mg/ml)
You have 5 mg of a 1% solution. How much solvent do you need?
1% * 10 = 10 mg/ml
Y ml = 5 mg ÷ 10 mg/ml
Y ml = 0.5 ml
Ratios
Drug solutions may be expressed as a ratio instead of
a percentage
A 1:100 solution is a 1% solution and a 1:200 solution
is a 0.5 % solution
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This is derived by the following equation for a 1:100 solution
1/100 = 0.01 then multiply by 100 to give a percentage
Thus 0.01 * 100 = 1%
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For a 1:200 solution we do the same thing
1/200 = 0.005 then we multiply that by 100
Thus 0.005 * 100 = 0.5%
Ratios
We can determine the desired solute or
solvent with a simple equation
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Solution
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10 ml of a 1:100 solution. How much solute do
we need?
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Convert the 1:100 ratio into grams per ml
Take 1 and multiply it by 1000 to give us 1000 mg
Add ml to 100 so now we have 1000 mg/100 ml
Ratios
1000m g Y m g
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100m l 10m l
1000m g * 10m l
 Y mg
100m l
100m g  Y m g
Solvent
10 mg of a 1:200 solution. How much
solution do we need?
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Set up the equation as before
1000m g 10 m g
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200m l
Y ml
200m l *10m g
 Y ml
1000m g
2m l  Y m l
Nervous system
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Sympathetic nervous system
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Adrenergic
Uses epinephrine as a neurotransmitter
Fight or flight
Dilates pupils
Dilates bronchioles
Speeds up heart rate
Secretes adrenaline
Nervous system
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Parasympathetic nervous system
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Cholinergic
Uses acetylcholine as a neurotransmitter
Feed or breed
Constricts pupils
Constricts bronchioles
Slows down heart rate
Nervous system
Adrenergic stimulation
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Three adrenergic receptors
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Alpha: Vasoconstriction
Beta 1: Increased cardiac rate and strength of
contraction
Beta 2: Bronchodilation
Nervous system
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Adrenergic stimulation (cont)
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Stimulation of receptors with
sympathomimetic drugs causes
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Activation of adenylate cyclase
Increase conversion of atp into cyclic 3'5'amp
Results in bronchodilation
Nervous system
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Adrenergic stimulation (cont)
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Post stimulation
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Phosphodiesterase converts cyclic 3'5'amp into
5'amp
Break down of cyclic 3'5'amp ends
bronchodilation
Cholinergic stimulation
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Nicotinic receptors
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Stimulation affects all of the PNS and also
affects the sympathetic nervous system and
skeletal muscles
Causes paralysis of skeletal muscles
Increases production of dopamine (pleasure
response)
Muscarinic receptors :Stimulation of
receptors stimulates only the PNS
Specific sympathomimetics
Isoproterenol HCl
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Trade name – Isuprel
Generic - Isoproterenol HCl
Concentration - 1:200 (0.5%) solution
Receptor effects
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Alpha 0
Beta1 4+
Beta 2 4+
Short duration
Dosage: 0.25-0.5 ml QID or q 4 hours
Specific sympathomimetics
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Isoetharine
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Trade name: Bronkosol
Generic – Isoetharine
Concentration – 1:100 (1%) solution
Effects
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Alpha 0
Beta1 1+
Beta2 3+
Duration – medium
Specific sympathomimetics
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Isoetharine (cont)
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Dosage
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0.25-0.5ml QID
1cc maximum
Specific sympathomimetics
Metaproterenol sulfate
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Trade
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Generic - Metaproterenol sulfate
Concentration – 5% solution
Effects
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Alupent
Metaprel
Alpha – 0
Beta1 - 2+
Beta2 - 2+
Medium duration (2 – 4 hrs)
Dosage
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0.2 - 0.3 ml tid, qid
Maximum dose is 0.3 ml
Specific sympathomimetics
Racemic epinephrine
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Trade name
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Generic - Racemic epinephrine
Concentration - 2.25%
Receptor effects
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Vaponephrine
Micronephrine
Asthmanephrine
Alpha 2+
Beta1 3+
Beta2 2+
Duration of 0.5 - 2 hours
Dosage: 0.25 - 0.5 ml q1-2 hours
Specific sympathomimetics
Epinephrine HCl
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Trade – Adrenalin
Generic
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Receptor effects
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Epinephrine HCl
Alpha - 3+
Beta1 - 4+
Beta2 - 3+
Concentration - 1:100 (1%) solution
Short duration
Dosage: 0.2 – 0.5 ml q2-4 hours
Specific sympathomimetics
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Salbutamol, Albuterol
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Trade name
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Ventolin
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Proventil
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Generic name
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International – salbutamol
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US – albuterol
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Receptor effects
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Alpha – 0
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Beta1 - 1+
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Beta2 - 4+
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Concentration - 1:200 (0.5%) solution
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Long duration
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Dosage
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MDI 2 puffs TID, QID
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0.5 ml TID, QID
Specific sympathomimetics
Terbutaline sulfate
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Trade name
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Generic name - terbutaline sulfate
Receptor effect
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Bricanyl
Brethine
Alpha – 0
Beta1 - 1+
Beta2 - 3+
Concentration - 200 µg/puff
Long duration
Dosage: 2 puffs q4-6 hours
Specific sympathomimetics
Levalbuterol
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Trade name: Xopenex
(R)-Isomer of Albuterol
Very specific Beta2 agonist
Same Beta2 as Albuterol
No Alpha effects and almost no Beta1 effects
Dosage
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0.63 mg every 6 to 8 hours
1.25 mg TID
Long duration
Specific sympathomimetics
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Side effects of adrenergic bronchodilators
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Palpitations
Tachycardia
Hypertension
Restlessness
Fear
Anxiety
Tremor
Weakness
Dizziness
Pallor
Xanthines
Inhibits phosphodiesterase thus maintaining
levels of cyclic 3'5'amp
This results in better bronchodilation
Types
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Theophylline: Available in tablet and elixir form
Aminophylline
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Administered IV or in tablet form
After a loading dose, serum levels are monitored
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Therapeutic serum level of 10-20 mg/dl
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Xanthines
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Side effects
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Dizziness
Headache
Restlessness
Palpitations, tachycardia
Nausea, vomiting
Anorexia
Xanthines
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Many physicians now disregard this
agent as a choice to treat asthma
routinely
Has found favor in treating acute asthma
attacks with hospital admittance
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Subcutaneous Epinephrine is often favored
as the first agent to try in
Status Asthmaticus
Parasympatholytics/anticholinergic
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Enhance sympathetic effects
Atrovent
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Ipratropium bromide
Contraindications
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Allergy to soybeans and peanuts
Blocks production of cGMP
Side effect: occasional dry mouth
Often used in conjunction with albuterol to
enhance bronchodilation
Parasympatholytics/anticholinergic
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Atropine
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Atropine sulfate
Frequently used in surgery
Blocks production of cGMP
Contraindications
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Sensitivity
Glaucoma
Tachycardia
Parasympatholytics/anticholinergic
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Atropine (cont)
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Side effects
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Dilated pupils
Thick drying of secretions
Dry mouth
Palpitations
Tachycardia
Corticosteroids
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Used in the management of the
inflammatory process associated with
asthma, reactive airway disease, and
other pulmonary disorders
Administered orally or aerosolized
Corticosteroids
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Side effects
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Inhaled
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Oral candidiasis
Throat irritation
Dry mouth
Systemic
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Cushing’s syndrome
Immunosuppression
Diabetes
Corticosteroids
Aerosolized steroids
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Dexamethasone
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Decadron
MDI provides 84 µg per inhalation
Dosage
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3 to 4 puffs 3 to 4 times a day
Not to exceed 12 puffs per day
Corticosteroids
Aerosolized steroids (cont)
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Beclomethasone diproprionate
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Vanceril, beclovent
MDI provides 42 µg per inhalation
Dosage
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2 puffs 3 to 4 times a day
Not to exceed 12 puffs per day
Corticosteroids
Aerosolized steroids (cont)
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Flunisolide
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Aerobid
MDI provides 250µg per inhalation
Dosage
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2 puffs 2 times a day
Not to exceed 4 puffs per day
Corticosteroids
Aerosolized steroids (cont)
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Triamcinolone acetonide
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Azmacort,
MDI provides 100 µg per inhalation
Dosage
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2 puffs 3 to 4 times a day
Not to exceed 12 puffs per day
Budesonide - Pulmicort
Respules - 0.25 mg/2 ml , 0.5 mg/2 ml
Turbuhaler – (DPI) 1-2 inhalations twice daily
Corticosteroids
Aerosolized steroids (cont)
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Fluticasone propionate
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Flovent
MDI provides 44, 110, or 220 µg per inhalation
Dosage
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2 puffs of 44 µg 2 times a day for mild asthma
4 puffs of 220 µg 2 times a day for severe asthma
Corticosteroids
Oral steroids
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Prednisone
Action
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Dosage
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Reduce inflammation
Potentiation of sympathomimetics
Loading dose of 4 mg per kg of body weight
Maintenance dose of 1 mg per kg
Therapeutic serum levels: 100 to 150 mcg/100ml
May be given for a 2-3 week period or long term
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To manage the patient’s condition more adequately
Long acting bronchodilators
Salmeterol xinafoate
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Serevent
DPI provides 50 µg per blister
1 blister BID
MDI provides 25 µg per puff
2 puffs BID
12 hour duration
20-60 minute onset
Maintenance therapy only – not for emergency
Long acting bronchodilators
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Formoterol
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Foradil
Dpi provides 12 µg per puff
1 puff bid
12 hour duration
15 minute onset
Even though rapid onset and peak effect,
better maintenance drug than rescue agent
Prophylactic
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Fluticasone propionate/salmeterol
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Advair
DPI – discus
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100 µg Flovent/50 µg serevent BID
250 µg Flovent/50 µg serevent BID
500 µg Flovent/50 µg serevent BID
Maintenance only – not for emergency
Prophylactic
Cromolyn sodium
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Intal
Stabilizes mast cell thus preventing histamine release
(degranulation)
Indicated for management of chronic extrinsic asthma and is
also effective as a prophylactic in patients who have intrinsic
asthma
Prophylactic effects require 2 to 4 weeks to reach maximal
levels
Not to be used during acute attack
MDI provides 800 µg per puff
2 puffs QID
SVN with one 20 mg ampule
1 ampule QID
Prophylactic
Nedocromil sodium
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Tilade
Stabilizes mast cells and has some anti-inflammatory
properties
Indicated as part of treatment regimen for management of
chronic allergic bronchitis and asthma
Blocks early and late asthmatic responses to a variety of
allergic and nonallergic triggers
Prophylactic effects require 2 to 4 weeks to reach maximal
levels
MDI provides 1.75 mg per puff
2 puffs QID
Leukotriene inhibitors
Leukotrienes are mediators of inflammation, edema,
and bronchoconstriction
Leukotriene activity can be inhibited by synthesis
inhibition or by receptor blocking
Types
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Zafirlukast
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Accolate
20 mg tablets BID
Montelukast
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Singulair
10 mg tablets once a day
Zileuton
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Zyflo
600 mg tablets QID
Antimicrobial agents
Antibiotics
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Tobramycin - TOBI
Gentamicin
Treats most gram-negative organisms
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Pseudomonas aeruginosa: Often seen in CF patients
Acinetobacter
Klebsiella
Enterobacter
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Treats some gram-positive organisms:
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Usually preceded by a bronchodilator
Staphylococcus aureus
Antimicrobial agents
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Antiviral
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Ribavirin
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Treatment of respiratory syncytial virus (RSV)
Causes bronchiolitis in infants
Indicated only in carefully selected infants and
young children with severe lower respiratory
tract infection
Delivered with a small particle aerosol
generator (SPAG)
Antimicrobial agents
Antiprotozoal
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Pentamidine isethionate (Nebu Pent)
Treat opportunistic pneumonia caused by
pneumocystis carinii
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Seen in immunocompromised patients such as AIDS
Must be given via a nebulizer with several one-way
valves and a scavenging expiratory filter
– in a negative pressure room or via portable filter
system
300mg (powder form) w/6ml Sterile Water
Treatment lasts about 15-20minutes
Antimicrobial agents
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Surfactant Replacement Therapy
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Premature or low birth weight infants often
develop IRDS
Primary cause is lack of surfactant at birth
Survanta and Exosurf Neonatal
Instilled via an ETT followed by manual
ventilation and positional changes
Restores WNL Lung Compliance in RDS of
the newborn
Equipment for administering
bronchodilator treatments
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Small volume nebulizers
Metered dose inhalers (MDI)
Dry powder inhalers (DPI)
Spacers
Mucokinetics (to move mucus)
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Diluents – wetting agents
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Thins the mucus making it easier to move
Distilled water
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Used in humidifiers
Osmolarity – hypotonic
Will be absorbed into interstitial space of tissue
May cause edema
Mucokinetics (to move mucus)
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Diluents – wetting agents (cont)
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Isotonic saline
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0.9% saline
Normal saline
Used as diluent for medication
Osmolarity - same as lung
Mucokinetics (to move mucus)
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Diluents – wetting agents (cont)
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Hypotonic saline
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Less than 0.9% saline
½ normal saline, 0.45% saline
Osmolarity - hypotonic will be absorbed into the
interstitial space
Used in USN due to evaporation of water from
small particles thus becoming isotonic by the
time it reaches the patient
Can increase airway resistance
Mucokinetics (to move mucus)
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Diluents – wetting agents (cont)
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Hypertonic saline
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Greater than 0.9% saline
Usually 5% saline
Used to induce sputum
Osmolarity - hypertonic
Draws fluid out of interstitial space to enhance
production
Can cause bronchospasms
Mucokinetics (to move mucus)
Mucolytics
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Acetylcysteine
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Mucomyst
Works by breaking down disulfide bonds of mucus
Dose: 10% or 20%
Indicated for thick mucoid secretions
Should be used with bronchodilator
May cause bronchospasm and/or nausea
Discard 96 hours after being opened
Mucokinetics (to move mucus)
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Mucolytics (cont)
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Sodium bicarbonate
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Raises ph of sputum
Viscosity breaks down
2-5 ml of 2% solution, 3-4 times a day
Mucokinetics (to move mucus)
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Mucolytics (cont)
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Deoxyribonuclease
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Dornavac
Proteolytic enzyme breaks down DNA bonds in
sputum
Reduces viscosity of sputum
50,000 – 100,000 units aerosolized up to 4 times
a day
Mucokinetics (to move mucus)
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Mucolytics (cont)
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Dornase alfa
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Pulmozyme
Genetically engineered peptide proteolytic
enzyme
Breaks down extracellular dna in purulent
secretions
Used to manage purulent mucoid secretions in
patients with cystic fibrosis
2.5 mg (1 ampule) aerosolized daily
Surface active
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Ethanol
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Ethyl alcohol (ETOH)
Dose: 5-15 ml of 30% - 50% every 30 minutes for two to
four treatments
Delivered by SVN or IPPB
Indicated for pulmonary edema
Alters surface tension thus popping bubbles
May cause
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Bronchospasm
Irritation
Dehydration
Alcohol intoxication
Contraindicated in patients taking Antabuse
Equipment for administering
mucokinetics & mucolytic
agents
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Small volume nebulizers
Large volume nebulizers
USN