Direct-Acting

• Epinephrine, Norepinephrine, Dopamine - natural catecholamines
• Isoproterenol - synthetic catecholamine
• Pharmacodynamics of Direct Acting non-selective agonists:

  A) Norepinephrine

  B) Epinephrine

  C) Dopamine

  D) Isoproterenol

  
• Epinephrine - potent vasoconstrictor and cardiac stimulant, DOC for Anaphylactic shock
• Norepinephrine aka "Levarterenol" - first line inotropic agent in the management of septic shock, systemically in certain types of hypotension
• Dopamine - immediate metabolic precursor of NE, DOC for septic shock
• Isoproterenol - potent bronchodilator, used in management of bronchial asthma and COPD
• Methoxamine - direct acting a1-receptor agonist, used to relieve attacks of paroxysmal supraventricular tachycardia
• Midodrine - used for the treatment of postural hypotension, prodrug that is hydrolyzed to desglymidodrine
• Phenylephrine - has longer duration of action than the catecholamines, used as mydriatic and decongestant
• Phenylpropanolamine - otc agent combined in numerous weight reduction and cold medications but withdrawn from otc in the USA because it is associated with Hemorrhagic stroke
• Xylometazoline and Oxymetazoline - topical nasal decongestant
• Phenylephrine, Naphazoline, Xylometazoline, and Oxymetazoline - also formulated as eye drops for temporary relief of minor eye redness or discomfort caused by minor irritants; sympathomimetics administered as ophthalmic drops are also useful in localizing the lesion in HORNER'S SYNDROME
• Rebound Hyperemia - after the drug wears off, the blood vessels will revert back to their original size, after prolonged used those blood vessels can permanently enlarge, causing the red eye to look even worse
• Rhinitis Medicamentosa - a condition of rebound nasal congestion suspected to be brought on by extended use of topical decongestants
• Clonidine - alternative drug for ADHD, used in treatment of diarrhea in diabetics, diminish menopausal hot flushes
• Methylphenidate - DOC for ADHD
• Labetalol - DOC for clonidine induced hypertension
• Sodium Nitroprusside (Nifedipine in PH) - DOC for clonidine induced hypertensive crisis
• Methyldopa - a prodrug, alternative in mgt. of HTN during pregnancy
• Guanfacine and Guanabenz - used in mild to moderate hypertension, in combination with a diuretic
• Apraclonidine and Brimonidine - analog of clonidine, lower intraocular pressure and are approved for use in glaucoma with direct neuroprotective effects
• Dexmedetomidine - centrally acting alpha 2-selective agonist, used in sedation of px during treatment in an intensive care setting
• Tizanidine - central muscle relaxant, congener of clonidine, used in multiple sclerosis
• Dobutamine - chemical structure resembles dopamine, can reveal areas of ischemia, used as a pharmacologic cardiac stress test
• Drugs for bronchial asthma:

  A) Salbutamol

  B) Terbutaline

  C) Pirbuterol

  D) Fenoterol

  E) Salmeterol

  F) Bambuterol

  G) Fluticasone

  H) Budesonide

  
• Terbutaline, Ritodrine, Isoxuprine - drugs that are used as tocolytic agents
• Terbutaline - used in mgt. of symptomatic bradycardia
• Fenoldopam - peripheral vasodilation in some vascual beds
• Bromocriptine, Pergolide, Ropinirole - mimics dopamine actions in CNS, used in Parkinson's disease, and Prolactinemia