Unit 5 Chapter 7 Anticholinergics Flashcards
Atropine, Atrovent and Spiriva are all examples of this type of drug
anticholinergic (parasympatholytic
Anticholinergic drugs achieve bronchodlilation through (direct) (indirect) action.
indirect
What is the mechanism of action of anticholinergic drugs?
they work by blocking the receptors that cause bronchoconstriction.
What is the difference between the mechanism of action of beta adrenergics and anticholinergics?
beta adrenergics actively stimulate dilation of smooth bronchial muscles. Anticholinergics block cholinergic bronchoconstriction.
What is the trade name for ipratropium bromide?
Atrovent
What is the dosage for Atrovent?
MDI 18 ug/puff- 2 puffs qid
SVN: 0.5 mg, 0.02% solution qid
Ipratropium bromide is FDA approved for use in what patient populations?
Approved for maintenance treatment in COPD, including chronic bronchitis and emphysema
Historically, anticholinergics, specifically atropine, were developed from what plant?
atropa belladonna and the datura plant
Although approved for COPD only, anticholinergics may be prescribed for severe asthma under what conditions?
In addition to beta agonists if the patient does not respond well to beta agonist therapies
Name the 3 specific anticholinergic agents we use in RT (generic and trade name please!)
ipratropium bromide / atrovent
ipratropium bromide and albuterol / combivent
tiotropium bromide and albuterol / duoneb or spiriva
Atropine is not used by RT to treat bronchoconstriction. Why?
It has many systemic and undesirable side effects: it crosses the blood brain barrier, causes CNS effects, cardiac effects, eye effects (specific contraindication for glaucoma patients); genitourinary and gastrointestinal effects
What is the onset and peak and duration of action for atrovent?
Onset- 15 minutes
Peak- 1-2 hours
Duration of action: 4-6 hours
What is the peak effect for beta agonists?
20-30 minutes
How do the clinical effects of ipratropium bromide differ from beta agonists among patient populations?
Asthmatics metabolize ipratropium bromide faster. The duration of action is 1-2 hours longer in CODP patients
Why are anticholinergic nasal sprays prescribed?
for symptomatic relief of allergic and nonallergic perennial rhinitis (post-nasal drip, sneezing, runny or stuffy nose) and the common cold
What are some of the side effects of anticholineric drugs?
dry mouth, cough, mydriasis (pupil dilation); flattening of the lens, inhibition of tear formation (dry eyes), urinary retention, gastric disturbances, decreased mucociliary clearance
We say combivent and duoneb are synergictic drugs. What does that mean?
they produce a more beneficial clinical effect together with albuterol then either drug given alone
Give an example of a tertiary compound
Atropine sulfate, scopolamine,
Given examples of quaternary compounds
ipratropium ,tiotropium and glycopyrrolate
What is are some major differences between tertiary and quaternary compounds?
Quaternary do not cross the blood brain barrier. They are poorly absorbed in the blood stream due to low lipid solubility and their systemic effects are minimal
What is the trade name for tiotropium bromide?
spiriva
What is the peak and the duration of action for spiriva
peaks in five minutes but then declines rapidly to a low level within 1 hour. The duration of action is 24 hours.
What is the route and dosage for spiriva?
via DPI (difficult device- small table must be pierced) 18 ug/inhalation one time daily
Which provides a greater FEV1 result, impratropium bromide (atrovent) or tiotropium bromide (spiriva)?
tiopropium bromide
You have a 56 yo male patient with stage 2 COPD who has been hospitalized for an exacerbation. His doctor has prescribed duoneb qid and spiriva qd. You should:
A. Give the patient his spiriva at 0800 round and come back at 0900 to give the duoneb
B. Give the patient both medications at 0800 rounds
C. Only give one and discontinue the order for the other
D. Contact the physician
D. Contact the physician
What happens when the vagus nerve is stimulated?
heart rate decreases
Name the EFFECTs of tertiary anticholinergics such as atropine
bronchodilation decreased mucociliary clearance block hypersecretion alter CNS function Increase/decrease heart rate depending on dosage Dry mouth, dspagia, dysphonia urniary retention
Name the EFFECTs of quarternary anticholinergics (such as ipratropium)
bronchodilation
dry mouth
blocks nasal hypersecretion
More anticholinergic receptors are found here than anywhere else in the lungs
large to midsize airways (3-8 mm)
there are NO receptors in the smaller proximal airways or bronchioles. They are found mainly on epithelium, submucosal glands, smooth muscles and mast cells.
What drug will produce bronchoconstriction?
methycholine
Which system is responsible for bronchomotor tone?
parasympathetic system
What type of fibers are effected by vagally mediated bronchospasm?
sensory “C” fibers
What types of stimuli effect vagally medicated bronchospasm?
aerosols, cold air, high flow gas, cig smoke, histamines
Why do anticholinergics have little or no dilating effect for some, but work well for others?
It there is minimal muscle tone to be blocked (say just a basal or resting rate), these drugs will have minimal or no effect
When C fibers are activated, they send afferent nerve impulses to the CNS resulting an efferent impulse to cause bronchoconstriction, mucus secretion and cough. What function does this serve?
It is a protective mechanism
What drugs treat vagally mediated reflex bronchoconstriction?
anticholinergic agents are antagonists for this type of response
What is the best treatment for exercise induced asthma?
anticholinergics because deep breaths can result in a cough or increase in bronchomotor tone
Your 26 year old patient has presented to the ED complaining of an asthma exacerbation. The patient states that they have taken 12 puffs from their rescue inhaler in the last 4 hours. What drug therapy would you recommend to the doctor?
atrovent- it will treat bronchoconstriction caused by beta blockade and cholinergic agents
When would you use aerosolized lidocaine and why?
Bronchoscopy. It will inhibit reflex bronchoconstriction by blocking irritant receptors
At least a portion of the obstruction that occurs in COPD may be due to what mechanism?
vagally mediated reflex bronchoconstriction
Briefly relate the parasympathetic receptor theory
ACH stimulates a muscarinic receptor. Once stimulated muscarinic receptors stimulate the cell membrane to release the enzyme gyanylate cyclase into the cell. The GC enzyme converts GTP to cyclic 3’5’ GMP which causes bronchoconstriction and enhances the release of inflammatory chemicals from the mast cells.
The enzyme phosphodiesterase breaks down cyclic 3’5’ GMP into ‘5GMP which has no effect on bronchial muscle.
What blocks muscarinic receptors?
parasympatholytic agents
Which muscarinic receptors work on the smooth airway muscle and submucosal glands that increase secretions and cause bronchoconstriction?
M3 receptors
Stimulation of muscarinic ____ receptors cause bronchoconstriction by what mechanism?
M3, release of intracellular calcium
What RT drug will block M3 receptors?
ipratropium and tiotropium
Anticholinergic agents are classified as (agonists) (antagonists) (competitive agonists) for ACH at muscarinic receptors?
competitive agonists
Which muscarinic receptors does Atrovent block?
M1, M2, and M3
Which muscarinic receptors does Spiriva block?
M1, M2, and M3. BUT it stays longer at the M1 and M3 sites which is why it works for 24 hours
Where are M1 receptors located? What happens when they are stimulated?
parasympathetic ganglia. when stimulated they cause cholinergic neurotransmission and bronchoconstriction and also cause the release of acetylcholine (ACH)
Where are M2 receptors located? What happens when they are stimulated?
They are auto receptors (NOT FOUND IN NOSE). They inhibit further release of ACH. If these receptors are blocked the can actually increase the release of ACH and could offset the bronchodilating effects of ipratropium
When administering atrovent what precautions should you take?
Use with caution in patients with enlarged prostate glands, patients with urinary retention problems and patients with glaucoma. Proper use of MDI and SVN is essential to minimize eye effects. Use a mouthpiece and reservoir whenever possible NOT a mask :)
Your patient is allergic to soy and peanuts. Should you give ipratropium bromide?
Use with caution. Patients who are sensitive to soy/peanuts may also have a hypersensitivity to the ingredients in atrovent!
Your patient has wheezing caused by bronchospasms in the small airways. What is the best choice of bronchodilator for this patient?
a beta agonist
Which class of drugs tend to work fastest to relieve bronchoconstriction: anticholinergics or beta agonists?
beta agonists
Which class of drugs tend to work longer to relieve bronchoconstriction: anticholinergics or beta agonists?
anticholinergics
Do anticholinergics generally cause tremor as a side effect?
no
Which class of drugs works in the larger, upper airways? anticholinergics or beta agonists?
anticholinergics
Is there a tolerance effect using anticholinergic drugs?
no
Patients have been known to have a small drop in FIO2 levels after receiving which class of drugs- anticholinergics or beta agonists?
beta agonists
