L3 Adrenergic Stimulants (Exam #1) Flashcards
What is the role of indirect-acting adrenergic effectors? Give four examples
Act on presynaptic neuron
- Cocaine, amphetamines, MAOIs, tyramine
What is the role of direct-acting adrenergic effectors?
Act on receptors directly to mimic SNS
How does denervation affect indirect-acting adrenergic effectors, and direct-acting adrenergic effectors?
- Indirect: stops any activity
- Direct: can enhance activity
Which receptors does Norepinephrine (Levophed) act on?
A = B1
What is the primary use of Norepinephrine (Levophed), and how common is its use?
Increase BP in hypotensive crisis
- Rarely used - “give Levophed or leave them dead”
What is the primary AE associated with Norepinephrine (Levophed)?
Vasoconstriction/tissue necrosis at infusion site
Which receptors does Epinephrine (Adrenalin) act on?
All (B1 = B2 > A1)
What are the four primary uses of Epinephrine (Adrenalin)?
- Anaphylactic shock
- Vasoconstrictor (local anesthesia)
- Emergency tx for cardiac arrest or complete heart block
- Glaucoma (increases removal of fluid, decreases production of fluid)
How does low dose Epinephrine (Adrenalin) vs. high dose Epinephrine (Adrenalin) affect the CV system? Which dose is more commonly used clinically?
- Low dose: B2 receptors = vasodilation = increase HR, but no change in BP
- High dose: A1 receptors = override vasodilation and cause vasoconstriction = increase BP and HR then baroreflex slows HR; more common clinically
How do A-blockers affect Epinephrine (Adrenalin)? How do B-blockers affect Epinephrine (Adrenalin)?
- A-blockers reverse Epi effect (lower BP)
- B-blockers increase BP without increasing HR
What are the five primary AEs associated with Epinephrine (Adrenalin)?
- Tremors
- Throbbing HA
- Increase BP
- Increase HR
- Cause angina in CAD pts
What route of administration is preferred for Epinephrine (Adrenalin), and why?
IV because it will activate the B2 receptors (vasodilation) and prevent tissue necrosis or severe HTN
What is the primary CI associated with Epinephrine (Adrenalin), and why?
Patients using B-blockers because then A is unopposed and this can cause severe HTN
What is the primary action of Phenylephrine (Neofrin), and what are its three primary uses?
- Increase BP in hypotensive emergency (VASOCONSTRICTS)
- Decongestant (VASOCONSTRICTS)
- Mydriasis (contract radial muscle)
What are the two primary AEs associated with Phenylephrine (Neofrin)?
- Rebound effect (down regulation then upregulation causing increased stuffiness)
- Ischemia of mucous membranes with prolonged use
What are the two primary CIs associated with Phenylephrine (Neofrin)?
- HTN
- BPH
What medication is Pseudophedrine (Sudafed) similar to, and how is it different?
Pseudophedrine (Sudafed) is similar to Phenylephrine (Neofrin) but it is MORE effective
- Beware OTC because can make meth lol
What are the two primary uses of Oxymetazoline (Afrin)?
- Nasal congestion (topical)
- Eye redness (topical)
What are the two primary CIs associated with Oxymetazoline (Afrin)?
- Closed-angle glaucoma
- HTN
What is the primary use of Clonidine and Methyldopa? What are two other possible uses?
In what group is Methyldopa considered the first line treatment for?
Treat HTN
- Can also decrease cravings in addicts and decrease hot flashes
Methyldopa is 1st line for HTN in pregnant women
What are the two primary AEs associated with Clonidine and Methyldopa?
What is a significant AE that is specific to Methyldopa?
- Xerostomia
- Sedation/CNS effects
Methyldopa can also cause hemolytic anemia (+ Coombs)
What are the two primary CIs associated with Clonidine?
- Sudden withdrawal can cause HTN crisis
- Hypotension if using patch and it gets hot
What is the primary use of Tizanidine?
Reduce muscle spasticity in neurological conditions
What is the primary AE associated with Tizanidine?
Asthenia
