adrenergic agonists

autonomic nervous system

• works with endocrine system

• goal is to maintine homeostasis

• regulates: BP/HR/temp/water balance/ urine/ digestion

• SNS/ PNS

sympathetic nervous system

• fight or flight

• aldostrone / epi / norepinephrine

• aldosterone retains sodium and water and spills potassium

parasympathetic nervous system

rest and digest

agonsits

stimulation of a normal response

antagonist

block a normal response

the action of an adrenergic agonist is to

mimic the normal response of the SNS

alpha 1 receptors

• vasoconstriction of arterites

• dilate the eyes

• close the bladder

• increase BP

Alpha 2 receptors

• vasodilate arteries

• decrease BP

• checks and balances

Beta 1 receptors

• once heart, and cells of kideny release renin

• increase BP

• increase heart contractility

beta 2 receptors

• two lungs, two eyes, arteries of skeletal muscle

• dilates vessels

• increase blood flow rich oxygen

• relax the uterus

use of adrenergic agonists

varies from ophthalamic preparations for dilating pupils to systemic preparations for shock

nursing actions for adrenergic agonist

• drug calculation

• criticle drips (very toxic)

• monitor pt (telemetry/ urine output)

• all can have systemic effects

• toxicity (HA, tremors, insomnia, vision, sob, dizziness, sensitive, sweat, palpitations, urine retention)

• OTC med check (phenylephrine/ cold&flu)

dobutamine indication

• congestive heart failure

• increases contractility

dopamine indication

• used to correct hemodynamics in shock

• post cardiac arrest

• lower BP

• lower cardiac output

• reduce perfusion to body organs

ephedrine indication

• seasonal rhinitis

• hypotensive episodes (increase BP)

epinephrine indication

• shock

• glaucoma

• prolongs regional anesthetics

• bronchospasms

norepineprine indication

treat shock during cardiac arrest to get sympathetic activity

antidote for extravasion with dopatime is

• phentolamine

• 5-10 ml

what is the pharmacokinetics of alpha and beta adrenergic agonist

• rapidy absorbed

• injection

• through mucous membranes

• metabolized in the liver

• excreted in the urine

contraindications of alpha and beta adrenergic agonsits

• pheochromocytoma (neuro-endorine disorder)

• tachyarrythmias

• ventricular fib

• hypovolemia (fluid overload)

• halogenated hydrocarbon general anesthetics

cautions for A/B adrenergic agonist

• any type of PVD

• preg/ lact

adverse affects of A/B adrenergic agonists

• arrhythmias

• HTN

• palpations

• angina / dyspnea

• hypokalemia

• NV / constipation

• headache / sweating / tension / anxiety

drug interactions for A/B adrenergic agonsits

• tricyclic antidepressants and MAOIs

• drugs causing HTN

• adrenergic antagonists

what is the action of dopamine

releases norepinephrine from SNS that results in dilation vessels to maintian renal perfusion while stimulating the SNS

adverse effects of dopamine

• tachycardia

• ectopic beats

• arrhythmias

• anginal pain

• HTN / hypotension

• dyspnea

• NV

• HA

ALPHA specific selevtive agonist

• phenylephrine

• midodrine

• clonidine

• brimonidine

• dexmedetomidine

• guafacine

indication of phenylephrine

• vasoconstriction on vessels

• nasal spray

• shock

• drops for eyes (glucoma)

midodrine indication

• increase vascular tone

• increase BP

• orthostatic hypotension

clonidine indication

• stimulations CNS alpha 2 receptors

• vasodilation

• prevents over stimulations SNS so decreases BP

• pain during cancer / epidural

brimonidine indication

topical for rosacea ( reduce swelling of the face)

dexmedetomidine

• heavily monitored

• sedation intubation

• ventilated patients

guanfacine

• PO

• ADHD

contraindications for alpha agonist

• hypertension

• tachycardia

• narrow angle glaucoma

• preg

caution for alpha agonsits

• CVD or vasomotor spasm

• thyrotoxicosis

• diabetes

• R/H impairment

• preg

adverse effects of all alpha agonists

• anxiety/ restlessness/ depression/ fatiuge/ blurred vision

• strange dreams/ personality changes/ sensitivity to light

• ECG changes / arrythmias/ BP changes/ NV / anorexia

• decreased urinary output

• urine retention

drug to drug interactions for alpha agonists

• MAOIs and TCAs + phenylephrine (HTN, hyperpyrexia)

• digoxin, beta blockers, antipsychotics + midodrine (increase effects of all meds)

• adrenergic antagonist = decrease effects of agonist

teachings for alpha agonist

• do not stop abruptly (rebound tachy, increase BP, arrhythmia, flushing, death)

• check VS, orthostatic, UA output, liver and renal function

• IV infiltration: phentolamine

phenylephrine is used to treat

• vascular failure in shock

• drug induced hypotension

• hypotention from prologed spinal anesthesia

• dilation of pupils

• decongestant

what are the adverse effects of phenylephrine

• fear

• anxiety

• restlessness

• HA

• nausea

• decreased urine formation

• pallor

beta 1 affects the

• heart

• cells

beta 2 affects the

• lungs

• skeletal muscle

• uterine smooth muscle

• glycogen breakdown

beta 3 affects

• adipose tissue

• GI tract

• bladder

• lipolysis

actions of beta specific adrenergic agonsit

• increase HR

• conductivity

• contractility

• bronchodilation

• increase blood flow to skeletal muscles and splanchic bed

• relaxation of uterus

pharmacokinetics of beta specific

metabolized in the liver and excreted in the urine

albuterol

• bronchospasm

• rescue drug

arformoterol

for COPD

formoterol and levalbuterol are for

asthma

isoproterenol

prototype beta specific

• shock

• cardiac arrest

• heart block

• prevention bronchospasm with anesthesia

• acute hyperkalemia

metaproterenol

• bronchial asthma

• bronchospasm

olodaterol and salmeterol are for

• asthma

• COPD

terbutaline

sq/po

• prevention bronchial asthma and bronchospasm

contraindications of beta specific agonists

• pulomary hypertension

• eclampsia/ uterine hemorrhage/ intrauterine death

• preg/ lact

cautions with beta specific agonists

• diabetes

• thyroid disease

• vasomotor problems

• heart disease

• stroke

• severe renal disease

adverse effects of beta specific agonists

• restlessness / anxiety / fear / tremors

• tachycardia / angina / MI

• SOB / cough / bronchospasm/ pulmoary edema

• nausea / vomiting / anorexia

• hypokalemia

• sweating / pupil dialtion / rash / muscle cramps

drug to drug interactions for beta specific agonist

• increase with other sympathomimetic drugs

• decrease with beta adrenergic blockers

isoproternol

• bronchospasm during anesthemia

• vasopressor during shock

• cardiac arrest

• ventricular arrhythmias

what is the action of isoproternol

acts on beta adrenergic receptors to produce increased heart rate, positive inotropic effect, bronchodilation, vasodilation

adverse effects of isoproternol

• restlessness

• anxiety

• cardiac arrhythmias

• tachy cardia

• NV

• pulmonary edema

• pallor

• sweating