Adrenergics: Indirect Acting Adrenergic agonists Flashcards
release endogenous norepinephrine from nerve terminals
Indirect acting adrenergic antagonist
Indirect acting only :
only action is to release norepinephrine
What is my only indirect acting drug that’s only action is to release Nepi?
Tyramine
Tyramine releases Nepi from ________ nerves and causes sympathomimetic actions
Sympathetic
Found at high levels in certain foods (fermented foods such as wines, beer, certain cheeses and sausages)
Tyramine
What enZ will metabolizes tyramine to inactive prodcuts?
monoamine oxidase
Why type of drug do we need to be careful of if a patient is eating foods like wine, beer, cheese and sausages
In patients taking monoamine oxidase inhibitors, ingestion of food with high
levels of tyramine(beer, sausage, wine) can cause hypertensive crisis
Type of indirect acting adrenergic drug class that will increase Nepi release and stimulate adrenergic receptors
Mixed acting
Two examples of mixed acting indirect acting adrenergics
Ephedrine and Amphetamine
Amphetamine is a powerful sytimulant of :
CNS
Amphetamine is a powerful CNS stimulant in addition to:
peripheral α and β receptor actions
Amphetamine is effective after oral administration – ______ t 1⁄2
long
This drug releases NE from adrenergic neurons but also a weak direct α and β agonist
Amphetamine
Besides releasing NE from adrenergic neurons, what weaker effect does amphetamine have?
weak direct alpha and beta agonist
What affect does amphetamine have on the NE transporter (NET)?
weakly blocks the norepinephrine transporter (NET)
What effect does amphetamine have on appetite?
- Depresses appetite
This drug therapy is used to treat narcolepsy, attention deficit disorder
Amphetamines
Ephedrine has____ asymmetric carbons creating ____isomers
two
4
4 isomers of ephedrine:
: d- and l- ephedrine and d- and l- pseudoephedrine
Ephedrine is effective:
Orally
Ephedrine works how and on which receptors?
direct agonist (α and β receptors) and releases NE that activates adrenergic receptors
What does ephedrine do to CNS?
CNS stimulation
some herbal preparations contain ephedrine (ma huang, ephedra), resultin in
inadvertent consumption of high doses of ephedrine
previously used to treat asthma, but has been replaced by β2 agonists -
Ephedrine
Pseudoephedrine
- direct _______activity with little ______activity
α1 agonist
β2 agonist
Major therapeutic use: nasal decongestant (due to α1 agonist effects)
pseudophedrine
used as a precursor to illegally synthesize methamphetamine
psedophedrine;
legislation in 2006 requires pharmacies to collect personal information from buyers and to limit its sale to a 30-day supply
Why is pseudophedrine a good drug therapy for nasal decongestant?
because of it’s alpha 1 agonist effects
Side effects and toxicity of adrenergic agonists
1. Throbbing headache due to potent vasoconstriction – (receptor and action responsible
α agonists
Side effects and toxicity of adrenergic agonists
Increased heart rate (palpitations) (receptor and action responsible)
β agonists
Side effect and toxicity of adrenergic agonist: Pericardial pain (angina) usually due to increased heart rate (receptor and action responsible)
β agonists
Side effect and toxicity of adrentergic agonist: Cardiac arrhythmias -(receptor and action responsible)
β agonists
Side effect and toxicity of adrenergic agonist: Cerebral hemorrhage – due to ↑ systemic blood pressure -(receptor and action responsible)
α agonists
Side effect and toxicity of adrenergic agonist:
Restlessness, anxiety, etc. (receptor and action responsible)
α and β agonists
