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 = 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)

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: minutes Aerosol dose: ml 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: minutes Aerosol dose:.25-.7ml Q4 Side effects: tachycardia, headache, hypertension, N&V, agitation/tremors, drying of mucosa and secretions

Isoetharine (Bronkosol, Bronkometer)

Strength: 1% Actions: Beta-2=3*, Beta-1=1* Duration: 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)

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 mg Q4-Q8 Side effects: Like Metaproterenol; tremors and agitation may be prominent Severe agitation seen when administered to children

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)

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)

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)

Good beta-2 (like Albuterol) but comes on quickly (within 5 minutes) Duration: 5 (sometimes 6) hours Given by breath-activated MDI

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