ANS DRUGS

Anatomy & Physiology (ANS)

• Common sign and symptom for all ANS drugs - nausea and vomiting
• SNS (sympathetic nervous system) - also called thoracolumbar system
• “Fight or Flight” System
• α1 receptor - blood vessels, iris, bladder
• α2 receptor - nerve impulses, regulate norepinephrine, inhibit α1
• β1 receptor - cardiac tissue, lipolysis
• β2 receptor - smooth muscles in blood vessels, bronchial periphery, uterine muscles, inhibits β1
• PSNS (parasympathetic nervous system) - also called craniosacral system
• “Rest & Digest” System
• Muscarinic receptor - increases GI motility, bladder contractions, decreases HR
• Nicotinic receptor - causes muscle contractions, autonomic responses

Adrenergic Agonists / Sympathomimetics

• α & β Agonists
• Nonselective, affects all receptors
• Epinephrine
• Increases HR, RR, BP, myocardial contractility, dilation of bronchi, vasoconstriction
• Norepinephrine (Levophed)
• Slows heart rate, increases BP
• Dopamine (Myocard), Dobutamine (Dobutrex)
• Increases myocardial contractility, BP, HR
• α-Specific
• Affects only α receptors
• Phenylephrine (Dimetapp, Neozep, Decolgen)
• FOR SHOCK
• Vasoconstrictor with no effect to heart
• Found in COLD & ALLERGY PRODUCTS (constricts nasal arterioles thereby reducing nasal congestion resulting from nasal edema)
• Clonidine (Catapres)
• ONLY SYMPATHOMIMETIC THAT TREATS HYPERTENSION
• BEWARE: TCA’s, MAOI’s, propranolol, midodrine
• β2-Specific
• Affects β2 receptors only
• Isoproterenol
• FOR BRONCHOSPASM, HEART BLOCKS, & SOME ARRHYTHMIAS
• BEWARE: sympathomimetics, β-blockers

Adrenergic Blockers / Sympatholytics

• BEWARE: ginseng, celery, sage
• α & β Blockers
• Nonselective, affects all receptors
• Decreases BP & HR, increases renal perfusion, decreases renin secretion
• Amiodarone - Antiarrhythmic
• Carvedilol - Hypertension & Congestive Heart Failure
• Labetolol - Hypertension
• α-Specific
• Affects only α receptors
• Phentolamine
• FOR PHEOCHROMOCYTOMA
• PREVENTS TISSUE NECROSIS FROM EXTRAVASATION OF DOPAMINE OR NOREPINEPHRINE
• Causes VASODILATION & DECREASES NOREPINEPHRINE
• BEWARE: ephedrine, epinephrine, alcohol
• α1-Selective
• Affects only α1 receptors
• Decreases vascular tone, vasodilates
• Doxazosin, Terazosin - treats hypertension & benign prostatic hypertrophy (BPH)
• Prazosin - treats hypertension
• Tamsulosin & Alfuzosin - treats benign prostatic hypertrophy (BPH)
• BEWARE: vasodilators, antihypertensives
• β-Specific
• Affects only β receptors
• Propranolol - treats hypertension, angina, reinfarction of MI, STAGE FRIGHT
• Blocks β receptors in heart & juxtaglomerular apparatus
• BEWARE: clonidine, NSAIDs, epinephrine, ergot derivatives, insulin, DM drugs
• β1-Selective
• Affects only β1 receptors 
  
• Atenolol (Therabloc), Bisoprolol, Metoprolol (Neobloc), Nebivolol - treats hypertension
• BEWARE: clonidine, NSAIDs, barbiturates, epinephrine, lidocaine, prazosin, diuretics
•  Nursing Considerations:
• DON’T stop drug abruptly
• Stop drug only after physician’s orders
• Monitor BP, HR, RR, cardiac output
• DASH (dietary approach to hypertension)diet
• Smoking cessation
• Exercise
• Alcohol moderation

Cholinergic Agonists / Parasympathomimetics

• Direct-Acting
• Bethanecol - urinary retention & bladder atony; reflux esophagitis
• Indirect-Acting
• Blocks acetylcholinesterase accumulation
• Only slows progression of disease, doesn’t cure it
• FOR MYASTHENIA GRAVIS
• Ambenonium
• FOR ALZHEIMER'S DISEASE
• Donepezil, Tacrine
• Nursing Considerations
• Have ATROPINE SULFATE on standby (antidote)
• Provide support groups for Alzheimer’s patients
• Obtain baseline data before administering drug

Cholinergic Blockers / Parasympatholytics

• Atropine, Scopolamine (Buscopan), Ipratropium (Atrovent), Methscopolamine
• Blocks acetylcholine
• Relaxes GIT & GUT
• Dilates bronchi
• Nursing Considerations:
• Adequate hydration & temperature control
• Proper drug administration
• Provide patient teaching
• Monitor patient responses
• Provide comfort measures