Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
43 Cards in this Set
- Front
- Back
|
What is the adrenergic system?
|
The adrenergic system includes neurons that synthesize and release NE into synapses and the adrenal medulla that synthesizes and releases Epi and NE into the bloodstream in a ratio of 4:1. Then there are the receptors for Epi and NE--includes parts of the CNS and the ANS.
|
|
|
Alpha 1 receptor
|
Post synaptic.
Gq-->phospholipase C, leads to an increase in IP3, DAG, and Ca++. |
|
|
Alpha 2 receptor
|
Mainly presynaptic (present on adrenergic neurons where their activation inhibits release of NE)
Gi-->adenylate cyclase, leads to a decrease in cAMP. |
|
|
Beta 1 receptor
|
Post synaptic
Gs-->adenylate cyclase, leads to an increase in cAMP |
|
|
Beta 2 receptor
|
Gs-->adenylate cyclase, leads to an increase in cAMP.
|
|
|
sympathomimetic drug
|
A substance that increase sympathetic activity. This can be achieved by directly stimulating adrenergic receptors or indirectly by increasing the levels of Epi or NE.
|
|
|
sypatholytic drug
|
A substance that decreases sympathetic activity. This can be achieved by directly blocking adrenergic receptors or indirectly by decreasing the levels of Epi or NE.
|
|
|
alpha-1 agonist
|
Clinical uses:
-nasal congestion -conjunctival hyperemia -hypotension adverse effects: -tissue necrosis (w/ extravasation) -hypertension -reflex bradycardia -rebound congestion -blurred vision -urinary retention -fetal hypoxia/bradycardia -diagnostic aid in opthalmology |
|
|
phenylephrine
|
alpha-1 agonist
Indications: -nasal congestion -diagnostic aid in optho -hypotension Pharmacokinetics: -metabolized by MAO (monoamine oxidase) Adverse Effects -tissue necrosis if extrav. -angina -marked bradycardia -hypertension -blurred vision Drug Interactions: -avoid w/ other direct or indirect sympathomimetics esp MAO inhibitors -no other vasoconstrictors -no w/ alpha 1 antagonists -no with atropine which blocks the vagal reflex bradycardia Cautions: -in patients taking antihypertensive agens -pregnancy: category C |
|
|
Beta-1 agonist
|
clinical uses:
-heart failure and cardiogenic shock Adverse effects: -angina -arrhythmias -tolerance |
|
|
Dobutamine
|
A Beta-1 agonist with wk Alpha-1 and Beta-2 agonist activity.
Indications: -heart failure -cardiogenic shock Pharmacokinetics: -administered by continuous IV -metabolized by COMT -v. short 1/2 life (2 mins) Contraindications: avoid in-- -pts w/ idiopathic hypertrophic subaortic stenosis -pts w/ atrial tachycardia/fib; there is a risk that an atrial arrhythmia can propagate to the ventricles since AV conduction is inc. -pts w/ coronary artery disease Adverse effects: -angina -arrhythmias Drug Interactions: avoid w/ -beta blockers -COMT inhibitors -hypertensive drugs Cautions: -pregnancy: category C |
|
|
Beta-2 agonist
|
Clinical Uses:
-bronchospasm -hyperkalemia -premature labor Adverse Effects: -hypokalemia -tremors -arrhythmias -worsening of diabetes mellitus -nausea, dyspepsia |
|
|
Albuterol
|
A beta-2 agonist
Indications: -acute bronchospasm -asthma -bronchospasm prophylaxis Pharmacokinetics: -mostly excreted by the kidneys Contraindications: avoid in pts -w/ idiopathic hypertrophic subaortic stenosis -w/ atrial tachycardia/fib -w/ coronary artery disease -w/ conditions that favor a long QT interval Adverse Effects: -sinus tachycardias and premature ventricular contractions -dyspepsia -hyperglycemia -hypokalemia -tremors Drug Interactions: avoid w/ -beta blockers (cause bronchoconstriction) -other beta agonists (cardiac risk) -MAO-inhibitors & tricyclic antidepressants -drugs that prolong the QT interval cautions: don't use w/ -renal impairment -diabetes mellitus -pregnancy: category C |
|
|
salmeterol
|
long acting Beta-2 agonist used for
-asthma -bronchospasm phrophylaxis -bronchitis -COPD |
|
|
isoproterenol
|
Beta-2 and Beta-1 agonist
used for: -AV block -cardiopulm resuscitation -acute bronchospasm *inc CO, inc HR, dec MAP |
|
|
Alpha-1 antagonists
|
Clinical Uses:
-hypertension -benign prostatic hyperplasia Adverse Effects: -orthostatic hypotension -nasal congestion -urinary urgency -drowsiness -male impotence |
|
|
Prazosin
|
An alpha-1 antagonist-short acting
Indications: -benign prostatic hyperplasia -HTN Adverse Effects: -intraoperative floppy iris syndrome during surgery for cataracts -hypotension -drowsiness -erectile dysfunction Drug Interactions avoid w/: -antihypertensive agents -MAO inhibitors due to additive hypotensive effects -NSAIDs due to inhibition of vasodilatory PG's -avoid ethanol due to potentiation of hypotensive effect -drugs w/ alpha-1 agonist activity Cautions pts w/: -angina b/c severe hypotension may cause or worsen angina -having occupations for which alertness is req. -elderly pts who are more susceptible to hypotension and drowsiness -pregnancy |
|
|
Beta-1 Antagonists
|
Clinical Uses:
-hypertension -angina and post MI ischemia -arrhythmia Adverse Effects: -congestive heart failure -av block -cardiac risks if abrupt withdrawal **at high doses, selective beta-1 antagonists have beta-2 antagonist activity** |
|
|
Atenolol
|
A beta-1 antagonist
Pharmacokinetics: -low-lipid solubility and eliminated by the kidneys Contraindications: -AV bock, sick sinus syndrome and severe bradycardia (all b/c of the depressed conduction through the AV node) -cardiogenic shok and acute pulmonary edema (b/c of the decreased cardiac output) Adverse Effects: -sinus bradycardia -AV block -hypotension -CHF Drug Interactions avoid w/: -drugs that significantly depress AV nodal conduction or myocardial function -NSAIDs (dec antihypertensive effects of beta-1 antagonists) -beta-1 agonists -antacids (dec F of atenolol) Cautions: -when stopping treatment reduce dosage gradually; abrupt withdrawal may exacerbate angina or precipitate rebound htn, MI, or ventricular arrhythmias -pts w/ renal impairment -pts w/ cerebrovascular disease -pts taking antihypertensives -pregnancy: category D |
|
|
Beta-2 antagonists
|
Clinical Uses:
-essential tremor -glaucoma Adverse Events: -bronchospasm -myalgia -increased peripheral resistance -diarrhea, nausea, vomiting -hyperglycemia **there is no selective beta-2 antagonist available. only non-selective beta-blockers are available** |
|
|
Propranolol
|
A beta-1 and beta-2 antagonist
Indications: -htn -angina -MI -supraventricular arrhythmia -tremor Pharmacokinetics: -highly lipophilic w/ hepatic elimination (CYP2D6) Contraindications: -AV block, sinus syndrome and severe bradycardia -cardiogenic shock and acute pulmonary edema -pulmonary diseases Adverse Effects: -sinus bradycardia, AV block, HTN, CHF -diarrhea, nausea, vomiting -myalgia, hyperglycemia Drug Interactions avoid w/ drugs -that significantly depress AV nodal conduction or myocardial function -NSAIDs (dec antihypertensive effects of beta-1 antagonists) -adrenergic agonists -inhibitors and inducers of CYP2D6 Cautions: -when stopping treatment reduce dosage gradually;abrupt withdrawal may xacerbate angina or precipitate rebound htn, mi, or ventricular arrhythmias -caution w/ pts w/ diabetes -initiate therapy w/ lower doses in pts w/ hepatic impairment -pregnancy: category c |
|
|
doxazosin, terazosin
|
benign prostatic hyperplasia, htn (shorter acting is prazosin, longer acting is doxazosin)
|
|
|
tamsulosin
|
benign prostatic hyperplasia
|
|
|
metoprolol
|
HTN, angina, MI, supraventricular arrhythmias, tremor
|
|
|
timolol
|
glaucoma, HTN, MI, migraine prophylaxis
|
|
|
carvedilol
|
HTN, angina, MI, heart failure
|
|
|
labetalol
|
HTN
|
|
|
Alpha-2 agonist
|
Clinical Uses:
-hypertension -opiate withdrawal -glaucoma -pain Adverse Effects -xerostomia -hypotension -constipation -sexual dysfunction -rebound hypertension -drowsiness **at high doses, selective alpha-2 agonists have alpha-1 agonist activity** |
|
|
Clonidine
|
An alpha-2 agonist
Indications: -HTN, severe pain, opiate withdrawal Pharmacokinetics: -highly lipid soluble -50% eliminated by kidneys Contraindications -breastfeeing Adverse Effects -HTN -drowsiness -constipation -xerostomia -erectile dysfunction Drug Interactions: avoid w/ -antihypertensive agents -CNS depressants -drugs that cause bradycardia -drugs that have alpha-1 agonist or alpha-2 antagonist activity Cautions: -when stopping treatment reduce dosage gradually to avoid severe rebound HTN -pts w/ cerebrovascular disease, MI, or severe heart failure -pts having occupations for which alertness is req. -pts w/ renal impairment -pregnancy: category |
|
|
Alpha-2 antagonists
|
Clinical Uses:
-erectile dysfunction Adverse effects: -HTN -tachycardia -anxiety -insomnia |
|
|
Yohimbine
|
An Alpha-2 antagonist
Indications: -erectile dysfunction Pharmacokinetics: -absorption v. variable Contraindications: -angina pecoris -cardiac disease -HTN -pregnancy and breast feeing Adverse Effects: -anxiety, insomnia -HTN -tachycardia Drug Interactions: avoid w/ -MAO inhibitors, tricyclic antidepressants and alpha-1 agonists -alpha-2 agonists Cautions -avoid in female patients -cnt w/ pts w/ hepatic disease or renal impairment -cnt in pts w/ depression or other psychiatric illness |
|
|
Brimonidine
|
Alpha 2 agonist
indications: glaucoma |
|
|
Methyldopa
|
Alpha-2 agonist
indications: HTN |
|
|
Phenoxybenzamine
|
alpha-1/ alpha-2 antagonist
indications: pheochromocytoma (irreversible antagonist) |
|
|
phenolamine
|
alpha-1/alpha-2 antagonists
indications: pheochromocytoma, dermal necrosis (reversible antagonist) |
|
|
Norepiniphrine
|
an Alpha-1, alpha-2, and Beta-1 agonist
indications: -cardiogenic shock -Hypotension -septic shock Parmacokinetics: -IV administration -very short 1/2 life Contraindications: -hypotension secondary to blood volume deficits Adverse Effets: -tissue necrosis if extravasation Drug Interactions: avoid w/ -beta blockers -alpha-blockers -atropine which blocks vagal reflex bradycardia -MAO inhibitors -vasopressors Cautions: -use with ctn w/ other adrenergic agonists -pregnancy: category c CO: stays the same HR: goes down MAP: goes up |
|
|
Epinephrine
|
An alpha1, alpha2, beta1, beta2 agonist
Indications: -bronchospasm -anaphylaxis -cardiopum resuscitation -glaucoma Pharmacokinetics: -IV, inhalation or topical administartion -v. short action Contraindications: -closed-angle glaucoma -hemorrhagic shock -intraarterial administration -labor -MAO inhibitor therapy -sulfite hypersensitivity. Adverse Effects: -angina -arrhythmias -dsypnesa -hypokalemia -tremors -tissue necrosis Drug Interactions: -avoid w/ MAO inhibitors, sympatholytics and sympathomimetics -avoid w/ vasopressors Cautions: -pregnancy: Category C **at high doses, the alpha-1 effects dominate **at low doses, the beta-1 and beta-2 effects dominate -inc CO -inc HR -inc MAP |
|
|
Dopamine
|
A dopaminergic, alpha-1, and beta-1 agonist
Indications: -hypotension -heart failure -cardiogenic and septic shock Pharmacokinetics: -IV administration -v. short half life Contraindications: -hypovolemia -pheochromocytoma -v fib and tachycardia Adverse Effects: -angina -dyspnea -hypotension, htn -arrhythmias -tissue necrosis if extrav. of high dose infusion Drug Interactions: avoid w/ -MAO inhibitors, sympatholytics and sympathomimetics -vasopressors Cautions: -pregnancy: category C **at v. high doses, the alpha-1 effects dominate **at high doses, the beta-1 effects dominate **at low doses, the dopaminergic effects dominate (vasodil of renal, mesenteric, and coronary vascular beds) -inc CO -inc HR -inc MAP |
|
|
Indirect Sympathomimetics: uptake inhibitors
|
Prolong the time that released NE remains in the synaptic cleft.
Ex: -cocaine -tricyclic antidepressants (amitriptyline) -methylphenidate |
|
|
Indirect Sympathomimetics: releasers
|
Reverse the action of the vesicle transporters, increasing the concentration of catecholamines in the cytoplasm which drives the uptake site in the reverse direction and releases the catecholamines:
Ex: Amphetamines Pseudoephedrine |
|
|
Indirect Sympathomimetics: metabolism inhibitors
|
Prolong the 1/2 lives of catecholamines. MAO inhibitors allow more catecholamines to be released w/ each action potential
MAO inhibitors: -phenelzine -selegiline -tranylcypromine |
|
|
Indirect Sympatholytics: synthesis inhibitors
|
inhibit the formation of all catecholamines
ex: -Metyrosine blocks tyrosine hydroxylase |
|
|
Indirect Sympatholytics: storage inhibitors
|
deplete the vesicular pool of catecholamines and the amount of catecholamines to be released w/ each action potential. However, prior to depletions, there is an inc in released catecholamines. So these agents are initially sympathomimetics and then sypatholytics.
ex: -Reserpine irreversibly damages the vesicles. |
