DL-HYOSCYAMINE

A toxic alkaloid extracted from belladonna and another members of thenightshade family, it is typically used to dilate the eye and to stopmuscular spasms. Pharmacologic action: Parasympatholytic. Competitive blockade of acetylcholine at muscarinic receptors. Increases sinus knot automaticity and AV conduction. Uses: Treat bradycardia, asystole, and AV block Dose: 0.5 - 1.0 mg for bradycardia each 3 - 5 min to a total doze of 0.04 mg/kg. Doses less than 0.5 mg can reason a paradoxical bradycardia due to sympathomimetic effects Typically 3 mg is adequate to completely block vagal effects Atropine is well absorbed via endotracheal route - administer 1-2 mg diluted in 10 mL sterile water or usual saline. Potential complications: 1. Tachyarrhythmias 2. Exacerbation of myocardial ischemia 3. Low doze may reason paradoxical bradycardia 4. Dry mouth, urinary retention, flushed and hot skin 5. Crosses blood-brain barrier which can reason delirium Note: The denervated heart will not respond to atropine.