Adrenegic Agonists Flashcards
Side effects of ALPHA 1 agonists
Vasoconstriction
Decongestion
Mydriasis
Site for adrenergic ALPHA 1 receptors
Vascular smooth muscle (constriction)
Receptors for ALPHA 2 agonists
Central sympathetic vase motor center
Clinical significance of ALPHA 2 agonists
Anti hypertensive
Receptors for BETA adrenergic agonists
Heart, lower respiratory smooth muscle, bladder wall, uterus, skeletal muscle vasculature
Clinical significance of BETA receptor agonists
Cardiac stimulation
Bronchodilation
Decrease uterine contractions
Key properties of catecholamines
Potent
Rapidly inactivated by COMT/MAO
Polar
Methoxamine receptor selectivity
Alpha 1
Indications for methoxamine
Maintain/restore/support BP
Reverse hypotension linked to shock
Evoke bradycardia to combat tachycardia (paroxysmal SV)
Pharmacokinetics of Methoxamine
Long duration of action
More CNS penetration
Adverse reactions to alpha 1 adrenergic receptors
Hypertensive headache, anxiety
Nausea & vomiting
Pulmonary edema
Cerebral hemorrhage
Phenylephrine receptor selectivity
Alpha 1> Alpha 2 adrenergic agonist
Indications for phenylephrine
Relieve nasal congestion
Evoke Mydriasis (avoiding cycloplegia)
Evoke reflex bradycardia
Phenylephrine pharmacokinetics
Non chatecholamine
Long duration of action
More CNS penetration
Why is phenylephrine preferred over anti-muscarinic agents as a myadritic?
Lack of cycloplegic effect = less of a chance of triggering latent or worsening glaucoma
Clonidine receptor selectivity
ALPHA 2 adrenergic agonist
Indications of Clonidine
Lower blood pressure in patients with HTN
Temper withdrawal from opiates/diazepenes
Treat diarrhea in diabetics
Diminish hot flashes