Adrenergics Flashcards
alpha 1 receptor
DAG IP3 Ca++ NE can act on it post synaptic; constriction f vessels; skin GI kidneys brain (will increase TPR and BP)
alpha 2
decrease production of cAMP, inhibit further release of NE from neuron, acts presynaptically, also reduces insulin (negative feedback), also inhibit acetylcholine
beta 2 smooth muscle
smooth muscle receptor + Epi – increase cAMP, reduce Ca++ intracellularly and sensitivity to myofilament, smooth muscle relaxes blood vessel dilates, reduce TPR BP goes down
beta 1 receptor cardiac myocyte
increase cAMP, increase PKA, phosphorylate L type channel on membrane increase influx of Ca++, increaes intracellular Ca++, cardiac myocyte will contract more and increase cardiac output
Beta 1 general
tachycardia, increase lipolysis, increase myocardial contractility, increase renin
Beta 2 general
vasodilate, decrease TPR, bronchodilation, increase muscle and liver glycogenolysis, increase glucagon, relax uterine smooth muscle
alpha 1 a
Tamsulosin selective alpha1A antagonist used to treat benign prostatic hyperplasia with fewer cardiovascular side effects. Alpha 1A primarily found urinary tracts, prostate gland
Oxymetazoline
alpha 1 and alpha 2 agonist; OTC in decongenstants and opthalmic drops, stimulate receptors on nasal mucosa and conjunctiva; absorbed in circulation, produces nervousness, headaches, troubled sleeping, local irritation and sneezing, rebound congestion and dependence
Phenylephrine
alpha 1 agonist, vasoconstrictor, raises systolic and diastolic BP, no effect on heart, produces reflex bradycardia, tx for hypotension in hospitalized pts wtih rapid HR, decongestant (replaced by pseudoephedrine) used in opthalmic sln for mydriasis; large doses can cause hypertension, headache and cardiac irregularities
Clonidine
alpha 2 agonist; acts on presynaptic neurons, decreases sympathetic outflow to the periphery, antihypertensive, minimizes withdrawal symptoms from opiates, tobacco, smoking, benzoiazepines, produces lethargy, sedation, consitpation, xerostomia, abrupt discontinuation causes rebound hypertension
Dobutamine
B1 agonist; increase heart rate and CO with no net effect on vasculature, used in heart failure to increase CO and as inotropic support after cardiac surgery; use w cuation in A Fib patients because it increases AV conduction
Albuterol & terbutaline
short acting B2 agonists; bronchodilators used in meter dose inhalers. albuterol is choice of tx in acute asthma, terbutaline not used in US and used to suppres premature labor; causes tremor, restlessness, apprehension, anxiety, oral may cause tachycardia or arrhytmia (b1) in pts w cardiac disease, contra w MAO inhibitors
Salmeterol and Formoterol
long acting selective B2 agonists; bronchodilators in meter dose inhaler cause sustain bronchodilation for 12 hrs. Salmeterol has delyaed onset. effective w corticosteroid. some increase in asthma related deaths. tx for nocturnal asthma.
Mirabegron
beta 3 agonist, relaxes detrusor smooth muscle, increase bladder capacity, may increase bp, may increase digoxin, decrease cyp2D6 that may enhance effect of drug metabolized by this pathwway like metoprolol
indirect adrenergic agonist
indirect agonist, can inhibit reuptake, cause release, inhibit degradation, potentiate effects of NE or Epi produced endogenously