Parasympatholytic

                                                                        Anticholinergic (vagolytic)

Blocks effects of parasympathetic innervation to the heart which                                                                                                      enhances both sinus node automaticity and AV conduction

                                                                        Relaxes smooth muscle in bronchial tree = bronchodilation

                                                      •                  Inhibits glandular secretion in respiratory tract

                                                      •                  Inhibits secretions from sweat and salivary glands

Symptomatic bradyarrhythmias

                                                      •                  Symptomatic conduction defects, ie. Stokes-Adams syndrome

                                                      •                 

CPA (asystole, PEA algorithm)

                                                      •                   Organophosphate (cholinergic) poisoning

                                                      •                  Status asthmaticus (aerosol nebulizer route)

Acute psychosis, vasodilation, dehydration, elevated surface temp., mydriasis.                                                                                          Mad as a hatter, red as a beet, dry as a bone, hot as a hare, blind as a bat.

MONITOR VS, EKG, & mental status

                                    •                 

May increase myocardial O2 demand in MI patients and aggravate chest pain                                                      •                 

Too low a dose may cause paradoxical bradycardia

                                    •                 

Exacerbation of glaucoma                                                                                                                                                                 

Can cause acute urinary retention in males with enlarged prostate

ACLS: Atropine has been reported to be harmful in some patients with AV block at the HIS-Purkinje  level (type II  AV block and third-degree AV block with a new wide-QRS complex). 

               Atropine may be used in these situations, but watch closely for paradoxical slowing.

Dose dependent sympathomimetic

At lower drip rates of 1-2 ug/kg/min, stimulate dopaminergic receptors                                                                              to produce cerebral, renal, and mesenteric vasodilation               

At drip rates of 2-10 ug/kg/min,  B1 effects predominate

(predominantly inotropic effect) with alpha effect beginning (vasoconstriction)

At drip rates 10 -20ug/kg/min, alpha effects predominate with renal, mesenteric, and peripheral arterial, and venous vasoconstriction with                                                                                          marked increae in SVR (systemic vascular resistance)

At drip rates > 20ug/kg/min alpha effects similar to norepinephrine predominate with marked peripheral vasoconstriction and tachycardia

Cardiogenic shock

Other types of shock after adequate fluid resuscitation                  

Symptomatic bradycardia unresponsive to Atropine or external pacemaker

Hypovolemia BEFORE fluid resuscitation

                                                                        •                  Pts. taking monamine oxidase inhibitors                                                                                                                                               

Pheochromocytoma (can precipitate hypertensive crisis)

                                                                        •                  Uncorrected tachyarrhythmias

Monitor VS and EKG

Stop infusion if diastolic pressure rises > 90 mm Hg                 

                                                      •                  Incompatible with NaHCO3 since alkaline environment may inactivate dopamine                                                                                                                                                                                           

Avoid extravasation which will cause tissue necrosis and tissue sloughing.  Inform ER RN or MD since local injection of Regitine will be required.