2: Adrenergic Drugs Flashcards
Adrenergic vs anti-adrenergic drugs can each be called what other names?
- Adrenergics: adrenomimetics, sympathomimetics
2. Anti-adrenergics: sympatholytics
6 Steps of signal transduction with a1 activation
- Activation of Gq protein
- Phospholipase C activation
- IP2 + DAG release
- IP3 stimulates Ca stores
- Activation of Ca-dependent protein kinases -> phosphorylate substrates
- DAG activates PKC
4 steps of signal transduction with B or a2 activation
- Activation of G2 protein
- Adenylyl cyclase activation
- Increased cAMP concentration
- PKA activation
How do indirect acting adrenergic drugs produce their effects?
Reduce or increase concentration of norep
Major receptors found in vascular beds of: skin/mucus membranes, skeletal muscle, and renal/cerebral
- Skin/mucus membranes: a1
- Skeletal muscle: a1, B2
- Renal, cerebral: a1, D1
What two drugs have a role in the baroreflex (increased BP causes decreased HR, etc.)
- Norep
2. Phenylephrine
Tyramine as an indirect adrenomimetic
Not a drug, but a product of decarboxylation of tyrosine - used for diagnostic purposes
Tyramine pressor test
Used to evaluate peripheral adrenergic function
CNS toxicity sx caused by indirect-acting lipophilic adrenergics
Insomnia, lack of appetite, anxiety, psychoses, convulsions
Most important adrenergic receptor in prostate smooth muscle contraction
A1a
How are some beta blockers actually partial agonists?
If theyre partial agonists, the sympathetic effects will be submaximal -> blunted sympathetic response
Type of activity that andrenergic partial agonists have
ISA: intrinsic sympathomimetic activity
Why are beta blockers used for hyperthyroidism?
Causes excess catecholamine actions on heart -> slows that down
What happens with long term use of beta blockers + if you stop using them**
Blocking Beta receptors causes compensatory upregulation of receptors -> if you stop using the beta blocker, there will be an increased response due to the increase in receptors
