Transcript Sympathomimetcs & Parasympatholytics

Sympathomimetcs &
Parasympatholytics
RC 195
Sympathomimetics
Drugs that “mimic” the actions of the
sympathetic neurotransmitters
Stimulate Alpha, Beta-1, and Beta-2
receptors
Also known as Adrenergics or
Catecholamines
Epinephrine (Adrenalin)
Note: The larger the sub-group on the terminal amine, the more
Beta-2 specific the drug will be
Epinephrine (Adrenalin)
Strengths: 1:100, 1:1000, 1:10000
Actions: Alpha=3*, Beta-1=4*, Beta-2
= 2*
Uses: Asthma,Bleeding/Prolonging
anesthesia, Stimulating the heart and
raising blood pressure during cardiac
arrest
Epinephrine (Adrenalin)
Duration = 120-180 minutes
Is metabolized by COMT
R & D: Aerosol, Sub-Q, IV
Aerosol dose is .25-.7ml Q4
Side effects: tachycardia, hypertension,
headache, N&V, thickened secretions
Isoproterenol (Isuprel)
Isoproterenol (Isuprel)
Strengths: 1% and .5% (most
common)
Actions: Beta-2 = 5*, Beta-1 = 4*
Is the most potent beta-2 that is approved
by the FDA!
Also stimulates cilia
No alpha stimulation
Isoproterenol (Isuprel)
Duration: 20-120 minutes
Aerosol dose: .125-.5ml Q4 of .5%
Can also be given IV
Side effects: tachycardia (never give
with epinephrine!), hypertension,
agitation/tremors, N&V, headache,
tolerance, and worsening of hypoxemia
(!?!?)
Racemic Epinephrine
(Vaponephrin, Micronefrin)
Is an isomer of epinephrine
Racemic Epinephrine
Strength: 2.25%
Actions: Alpha=3*, Beta1 and 2=2*
Uses: Upper Airway Inflammation
Croup
Smoke inhalation
Post-extubation glottic and sub-glottic
edema
Racemic Epinephrine
Duration: 120-180 minutes
Aerosol dose: .25-.7ml Q4
Side effects: tachycardia, headache,
hypertension, N&V, agitation/tremors,
drying of mucosa and secretions
Isoetharine (Bronkosol,
Bronkometer)
Isoetharine (Bronkosol,
Bronkometer)
Strength: 1%
Actions: Beta-2=3*, Beta-1=1*
Duration: 90-180 minutes
Aerosol dose: .25-1ml Q4
Dilution should be 1:3
Side effects: Headache,hypertension,
tachycardia, N&V, tremors/agitation
Turns brown when its too old to use
Turns clear sputum pink
Metaproterenol (Alupent,
Metaprel)
Metaproterenol (Metaprel,
Alupent)
Strength: 5%
Actions: Beta-2=4*, Beta-1=1 or 2*
Duration: 2-6 hours
Aerosol dose: .2-.3ml Q4
Side effects: tachycardia, headache,
N&V, tremors and agitation
Terbutaline (Breathine)
Terbutaline (Breathine)
Strength: .1%
Actions: Beta-2=4*, Beta-1=2*
Also stimulates cilia
Duration: 3-7 hours
R&D:Usually oral or sub-Q; if aerosolized give
.25-2.5 mg Q4-Q8
Side effects: Like Metaproterenol; tremors
and agitation may be prominent
Severe agitation seen when administered to
children
Albuterol/Salbutamol (Proventil,
Ventolin)
Albuterol/Salbutamol (Proventil,
Ventolin)
Strength: .5%
Actions: Like Metaproterenol and
Terbutaline
Duration: 4-6 hours
R&D: Oral, IV and Aerosol
Aerosol dose is .5ml of .5% Q4-6
Side effects: Like Metaprel and
Terbutaline but usually not as severe
Levo-Albuterol (Xopenex)
An isomer of Albuterol/Salbutamol
that has even less side effects than
Albuterol and may have a longer
duration in some patients
Fenoterol (Berotec)
Fenoterol (Berotec)
Strength: .5%
Actions: Beta-2 =4*, Beta-1=1*
Duration: up to 8 hours
R&D: Oral and Aerosol
Aerosol dose is .5ml of .5% Q6-8
Minimal side effects
Is not legal in the USA!
Ephedrine
Old time drug that is similar to epinephrine
Active ingredient in many “combo” drugs:
Quibron,Tedral, Marax
Stimulates all sympathetic receptors equally
and weakly
Taken orally (not aerosolized)
Not used much now because of (1)minimal
beta-2, (2) CNS stimulation, (3), tolerance
Bitolterol (Tornalate)
Bitolterol (Tornalate)
Activated by esterases in lung and
becomes colterol
May last up to 8 hours
Usually aerosolized by MDI
2-3 puffs Q4-6
May cause tremors and agitation
Always watch for any Beta-1 effects
Pirbuterol (MaxAir)
Pirbuterol (MaxAir)
Good beta-2 (like Albuterol) but comes
on quickly (within 5 minutes)
Duration: 5 (sometimes 6) hours
Given by breath-activated MDI
Salmeterol (Serevent)
Salmeterol (Serevent)
Very long-acting: 12 hours
Administered BID via MDI
Is for prevention, not relief!
Formoterol (Foradil)
Similar to salmeterol
Lasts for 12 hours
Given from a breath activated dry
powder inhaler
Carbuterol and Clenbuterol
New bronchodilators not yet
approved by the FDA
Phenylephrine
Pure alpha stimulant (5*)
Used for rhinitis (decongestant effect)
Side effects due to alpha stimulation:
Hypertension
Headache
Mucosal drying
Rebound congestion
Parasympatholytics
(Anticholinergics)
Blocking the parasympathetic
(cholinergic) system is similar to
stimulating the sympathetic
(adrenergic) system
Atropine
Actions: cholinergic blockade
Decreased c-GMP so decreased bronchospasm and
decreased mast cell degranulation
May potentiate beta-2 activity of
sympathomimetics
Decreased secretions (secretions may get thick
and dry)
• May also be helpful in rhinitis
Aerosol dose is 1 mg of 1% Q4-6
Side effects: tachycardia, dry mouth and dry
thick secretions, ataxia
Ipratropium Bromide (Atrovent)
Like Atropine but seems to have less
side effects and lasts a little longer
Can be nebulized or given via MDI
Often given with sympathomimetics
either concurrently or alternating
Seems to be very effective in COPD
patients who have “twitchy airways”
Tiotropium Bromide (Spiriva)
Like Atrovent, but only taken once per
day
Very good with COPD
Glycopyrrolate (Robinul)
Like Atropine and Atrovent
Usually only via nebulizer; 1 mg Q4-6