Komiskey: Anti-tussives and Mucolytics Flashcards
You should be able to describe the pharmacology of antitussives, expectorants, decongestants, and a drug that potentiates cystic fibrosis transmembrane regulator (CFTR) gating functions used in the treatment of respiratory problems.
You should be able to list the antitussives, expectorants, and decongestants used in the treatment of respiratory problems.
You should be able to describe the toxicity of antitussives (esp. dextromethorphan) , expectorants, decongestants, and a drug that potentiates CFTR gating functions used in the treatment of respiratory problems.
LOs
How/where do anti-tussives work? (narcotic and non-narcotic)
Cough center in the medulla
Cough centers in throat, lungs
What is the most common OTC ingredient in non-narcotic anti-tussives? In what common medications is it found?
Dextromethorphan. Robitussin, Tylenol, Nyquil
What is the ingredient in prescribed narcotic anti-tussives? What is it metabolized to in the liver?
Codeine; morphine
*the prescription should not last longer than one week due to addictive properties
Do you use an anti-tussive for a productive cough or for a non-productive cough?
Non-productive (dry cough)
How does benzonatate work?
It anesthetizes/numbs the cough reflex
SE of benzonatate?
HA, dizziness, sedation
SE of narcotic-type anti-tussive (codeine)?
sedation, nausea, constipation
**SE of Dextromethorphan?
dizziness, drowsiness, nausea
In which patients are opioid antitussives contraindicated?
premie babies or in labor when a premie is expected
COPD, asthma
What OTC drug are teens using in mass quantities to get high?
Dextromethorphan
What 3 drugs are highly dangerous and can send young people to the ER when combined with dextromethorphan?
non-drowsy anti-histamines
SSRI anti-depressants
MAOI inhibitors
What is the normal dose of cough medicine?
15-30 mg
What syndrome can occur in people taking dextromethorphan and how does it happen?
Dextrorphan binds to serotonin receptors which may contribute to its abuse potential. This also is a consideration in patients who have coingested another drug with serotonergic effects, such as the SSRIs. This combination has the potential to lead to serotonin syndrome.
There are genetic polymorphisms in CYP2D6, EMs will produce more dextrorphan and have more euphoric effects from DXM abuse than PMs
(PM: poor metabolizer; EM: extensive metabolizer)
How does dextromethorphan work?
Inhibits N-methyl-D-aspartate receptor and inhibits reuptake of serotonin
Describe the 4 plateaus of clinical effects in dextromethorphan abuse.
1st Plateau: 1.5-2.5mg/kg
- Mild alcohol-marijuana-like intoxication, GI
2nd Plateau: 2.5-7.5mg/kg
- Lethargy or agitation, ataxia, nystagmus, tachycardia
3rd Plateau: 7.5-15mg/kg
- Variable, often dysphoric, psychosis, disorientation, altered judgment may be severe
4th Plateau: > 15-30mg/kg
- Fully dissociative, seizures, hyperthermia, aspiration
What works best for nasal congestion?
intranasal steroids
How do decongestants work to reduce nasal congestion?
stimulate ALPHA RECEPTORS; act on blood vessels surrounding nasal sinuses.
sympathomimetics; stimulate the alpha-adrenergic receptors resulting in vasoconstriction=> decreased nasal hyperemia, decrease tissue edema, and decreased nasal congestion
Do anti-histamines work to relieve nasal congestion?
No. Need to add a decongestant for allergic rhinitis.
What are the 3 classifications of nasal decongestants?
- Adrenergics
- topical nasal sprays: Phenylephrine, Oxymetazoline, Naphthazoline, Tetrahydrozoline, Zylometazoline
- oral: pseudoephedrine, phenylephrine (alpha 1), oxymetazoline (alpha 2) - Anticholinergics
- Ipratropium - Corticosteroids
What are the three main actions of nasal corticosteroids?
reduce mucosal inflammation
reduce mucosal mast cells
suppress glandular activity and vascular leakage
induction of vasoconstriction
SE: irritation and dryness
What are the 4 mechanisms by which mucolytics decrease viscosity?
- hydration
- increase pH
- increase ionic strength (soda bicarb)
- rupture disulfide bond of the mucus (acetyl cysteine)
________ ________ is a precursor of glutathione, which is a major scavenger of free radicals.
acetyl cysteine. (mucus fragments become less viscous and can’t bind to inflammatory debris)
What can you use in patients with thicker more viscous mucus as seen in bronchitis, tobacco smoke, COPD, cystic fibrosis, asthma, TB, pneumonia, emphysema & ARDS?
acetyl cysteine
What is the wood tar derivative seen in Robitussin and Glytuss, useful in chronic bronchial disease?
Gauifenessin
What does Vicks Nyquil contain?
Acetaminophen
Pseudoephedrine, a decongestant,
Dextromethorphan, a cough suppressant
Antihistamine
In CF, what gene is affected causing the Cl to be stuck?
Cystic Fibrosis transmembrane regulator (CFTR)
Abnormal transport of chloride and sodium across epithelium which lead to thick and viscous secretions
What type of food should you advise your CF patient to eat when taking Ivacaftor?
fatty
In comparing Ivacaftor alone to the combo drug of ivacaftor/lumacaftor, which has a better SE profile?
Ivacaftor alone: Improved quality of life but SE a lot: HA, oropharyngeal pain, URIs, nasal congestion, diarrhea, rash, dizziness
Combo of ivacaftor with lumacaftor: less SE. (percentage-wise)
LUMA BRINGS THE CL- CHANNEL TO THE SURFACE, AND IVA WORKS ON IT TO OPEN IT UP ONCE IT’S THERE.
