Week 6: Bronchodilators Flashcards
What drug class is Albuterol (ProAir) in and indications for use? “terol’s”
SABA - short-acting beta-2 receptor agonist - also has a mild effect on beta-1 receptors as well
- used for asthma and COPD
Albuterol (SABAs) Pharmacodynamics
- activating beta 2 receptors acts on the smooth muscle of the bronchi to reverse bronchospasm by in the lungs, increasing vital capacity and airflow
- some effect on beta 1 receptors in the heart - causes side effects tachycardia, nervousness, etc.
Albuterol cautions/contraindications
- avoid in arrhythmias that cause tachycardia and pheochromocytoma (adrenal tumor- increased sympathetic response)
- can cause HTN
- caution in pts with CV disease (CHF, HTN), diabetes, glaucoma, and hyperthyroidism
Albuterol/SABA ADRs (usually transient)
tachycardia, dizziness, palpitations, tremors, nervousness, headache - ** due to effect on beta 1 receptors in the heart**
In Levalbuterol (Xopinex), the S-isomer has been removed. Why is this important?
This leaves only the R-isomer which is selective to beta-2 - removes the cardiovascular and CNS ADRs (tremors, tachycardia, etc.)
Examples of other SABAs
- terbutaline (Brethine, Brethaire)
- metaproterenol (Alupent)
- pirbuterol (Maxair)
- levalbuterol (Xopenex)
Three drug classes used for asthma
SABA - short-acting Beta 2 receptor antagonists
LABA - long-acting Beta 2 receptor antagonists **not as monotherapy in asthma**
ICS - inhaled corticosteroids
Salmeterol (Serevent) [LABA] MOA
- relaxes bronchial smooth muscle by selective action on beta 2 receptors
3 advantanges:
- 30-40 min onset
- Long MOA- last longer
- More selective to Beta-2 receptors which decreases the prevalence of side effects
Salmeterol (Serevent) drug class
Long-acting beta 2 receptor agonist (LABA)
Other examples of LABA medications
- formoterol (Foradil) - taken Q 12 hrs
- vilanterol (Breo Ellipta) - Ultra long acting - taken QD “Very easy to take”
LABA cautions/contraindications
- black box warning!
NOT to be used as mono-therapy in patients with asthma (salmetrol (Serevent) and Foradil) - causes downregulation of beta-2 receptors if used alone so in emergencies, short-acting beta-2 receptor antagonist medications (Albuterol) will not work - leads to increase in asthma intubations and death
- caution in pts with cardiovascular dz, diabetes, hyperthyroidism, glaucoma
Should a patient with asthma or COPD be placed on a beta blocker?
- patients who are taking SABA and LABAs should NOT take non-selective beta blockers. (ex. Propranolol, Carvadelol, Labetalol)
MR BEAN is selective and has no Nads. If a beta blocker begins with any letter in MR BEAN - it is beta 1 selective only except Nadolol (is non-selective). These beta-1 selective beta blockers would be OK to give with beta-2 antagonist drugs.
What drug class contains Theophylline?
Xanthine dervatives
Theophylline/xanthine dervatives MOA
- inhibits specific phosphodiesterases, increases cAMP = leads to relaxation of smooth muscle
- sympathamometic agent - works on the sympathetic nervous system: CNS stim., CV effects, increased fight/flight - has similar chemical structure to caffiene
- metabolized in the liver into caffeine (prodrug)
Theophylline - important to remember
- narrow therapeutic index - requires monitoring through blood draws
- range: 10-20 mcg/mL
- metabolized extensively via CYP 450 into caffeine so inhibitors (such as -azoles) will increase the effects and increase chance of toxicity
Xanthine derivatives ADRs and toxicity SE’s
SE: tachycardia, palpitations, irritability, GI upset, headache
Serum level >20 - N/V/D, insomnia, greater irritability, change in BP
> 35: hypotension, arrhythmias, seizures, brain damage, DEATH
avoid caffiene and smoking (increases excretion of it)
If serum blood of Theophylline is >35 (toxic level), what ADRs can occur?
- seizures, cardiac arrhythmias/torsade’s, death
Theophylline/Xanthine derivatives cautions/ contraindications
- monitor closely in cardiovascular disease
- avoid in pts w/ hx of seizures, peptic ulcer dz, sensitivity to xanthines
- educate patient to avoid smoking and caffeine
- educate pt on the signs of toxicity
- educate pt to maintain a steady diet
Ipratropium bromide (Atrovent) / SAMA MOA
selectively blocks M3 receptors in the lungs causing bronchodilation - muscarinic receptor antagonist
SAMA “-tropium” indictations and MOA
Mostly used for COPD - may be used in asthma exacerbation with albuterol (DuoNeb)
- selectively block the muscarinic 3 receptors in bronchial smooth muscle causing bronchodilation
- anticholinergic effects because muscarinic receptors are cholinergic receptors
Ipratropium bromide (Atrovent) = Immediate effects
Atrovent/Ipratropium bromide cautions/ contraindications
- only for asthma exacerbation IF COMBINED WITH ALBUTEROL (Duoneb)
- due to anticholinergic effects: avoid in pts with urinary retention, BPH, and closed-angle glaucoma
(Anticholinergic effects: patients can’t see, pee, spit, shit, or think)
Atrovent / SAMA adverse drug effects
cough, dry mouth, mouth and throat irritation, dyspepsia, nausea and vomiting
Ipratropium bromide (Atrovent)/SAMA patient education
- after use, rinse mouth and spit it out
Tiotropium bromide (Spiriva) Indications for use and MOA - LAMAs
Used primarily for COPD to control symptoms
Selectively block the muscarinic 3 receptors (muscarinic 3 receptor antagonist) in the lungs leading to smooth muscle bronchodilation
- long acting anticholinergic/muscarinic agent
Tiotropium bromide (Spiriva) cautions/ contraindications
- due to anticholinergic effects: avoid in pts with urinary retention, BPH, and closed-angle glaucoma
LAMA Adverse Drug Reactions
- dry mouth, pharyngitis, upper respiratory infection, headache, mouth irritation
- not approved for children < 12 years old
LAMA patient education
- Rinse mouth after inhaling medication
