1
What are the (2) types of postganglionic ANS pathway drugs?
1. SNS (adrenergic receptors)
2. PNS (cholinergic receptor)
What is the purpose of a MDI inhaler with a spacer?
Gets medication straight to the lungs and reduces side effects ***
- Typical tx lasts ~10-15 mins
- Increased secretions or coughing may result afterwards
- Relief or improved symptoms last 4-6 hours
- Increased dosage of an inhaler
Nebulizer (breathing) tx
End in -Terol (SABA) or -Tamol (LABA)
Bronchodilators/beta 2 agonists sympathomimetics
Which SNS receptor increases HR and force of contraction?
Beta 1 *** (targeting the heart)
A metered dose inhaler (MDI) delivers meds at what mph?
~ 60 mph
Which type of postganglionic ANS pathway drug?
- Acetylcholine
PNS (cholinergic receptor)
Which SNS receptor targets presynaptic neuron (decreased norepinephrine release) in the CNS
Alpha 2 (agonists)
Which SNS receptor negatively impacts upper respiratory tract?
Alpha 1
- Stimulate beta-2 receptors in respiratory smooth muscle, to cause:
- Bronchodilation and relaxation of bronchioles
- (also relaxes uterine mm.. releases insulin)
- Mimics action of SNS as a beta2 agonist, however, some are non-selective and stimulate beta1 receptors as well
- Short acting (SABA) and long acting (LABA)
Bronchodilators/beta 2 agonists sympathomimetics
Which type of postganglionic ANS pathway drug?
- Norepinephrine
- Epinephrine
- dopamine
SNS (adrenergic receptors)
Pills come in packet in a disc, flip it back and inhale.. pill becomes a powder with the force of a click.
Not chewing the pill... you're inhaling the powder
Patients may complain of the nasty taste and cause coughing
Powder diskus inhaler (accuhaler)
Which SNS receptor targets blood vessels (vasoconstrict)?
Alpha - 1 (agonists)
- Bronchodilator - symptom reliever
- EX: ventolin (albuterol)
- Rescue inhaler - carry at all times
- Quick acting (2-5 minutes)
- Use whenever SOB, up to 6 times/day
Sympathomimetics: Short acting beta 2 agonist (SABA)
Which SNS receptor dilates smooth muscles in lungs and bronchioles? (agonist)
Beta 2 ***
Used for:
- Hypotension
- Nasal congestion
- Congestion is caused by vasodilation of blood vessels in the nose [Agonist= vasoconstriction]
- EX: Nyquil severe cold and cough; Sudafed
Adverse effects: hypertension, blurred vision, constipation, urinary retention, goose bumps, sweating
Alpha 1 agonists
- EX: serevent (salmeterol)
- Long acting type
- Onset of action 30-45 mins
- Duration 12-24 h
- Taken 1-2x/day max
- Used as chronic "maintenance" medication for symptom prevention in COPD and asthma
- Should not be used without a steroid in asthma!!!!
Long acting beta 2 agonists (LABA)
- Mechanism not fully known
- May inhibit phosphodiesterase [enzyme released as histamine inflammatory response] to increase cAMP [from ATP to protein kinase] = smooth muscle relaxation/bronchodilation
- May also decrease inflammation due to the histamine inhibition
- cAMP = cyclic adenosine monophosphate
Xanthine derivatives -- bronchodilators - methylxanthines
- Cautions and adverse effects
- Tachycardia (resting can be 100-115 resting), palpitation, tremor, nervousness, glycemic changes, hypokalemia
- Use primary as inhaled agents for asthma/COPD
- Via meter-dose inhaler, dry powder inhaler or nebulizer Rx
- Decreased incidence of adverse effects vs. systemic with pills
Bronchodilators/beta 2 agonists sympathomimetics
- Generally end in -"phylline" (EX: theophylline)
* Has toxicity levels
Xanthine derivatives ***
- Numerous drug interactions
- Adverse effects
- Tachycardia, headache, insomnia, nausea, confusion, tremor, irritability, restlessness
- More serious adverse effects (arrythmias, seizures) as serum concentration increases
- Not often used due to toxicity and wide availability of other agents with less toxicity
- Naturally found in most caffeine products
- Can have + effect on mm. performance
Bronchodilators - Xanthine derivatives
What is the toxicity treatment for Xanthine derivatives?
Activated charcoal
- Resting HR is often elevated --> use Karvonen formula to calculate safe exercise intensity, which will take this elevation into consideration
- Rate perceived exertion and shortness of breath to indicate exercise tolerance
- Metered dose inhaler (MDI) of a sympathomimetic before exercise will minimize exercise induced bronchospasm but activity increases HR, so provide patient education
Bronchodilators/sympathomimetics: effects of SABA and LABA on exercise
Xanthine derivatives have a narrow therapeutic range (goal 10-20 mcg/mL)
- May see toxicity signs as early as 15-20 mcg/mL
- Seizures, dysrhythmias, hypotension
Xanthine derivatives
- MDI, powder inhaler
- Action: relax the muscle bands that surround the airways (cause bronchodilation)
- LT effects: reduce and/or prevent scarring in the airways
- WARNING LABEL: patient with mod-severe asthma: reactive bronchospasms may be fatal if not taken with steroid
- FDA recommends short stents only or combo use of steroids
Sympathomimetics: Long acting beta 2 agonist (LABA)