Anticholinergics Flashcards
1
Q
Atropine: class + structure + use
A
- ADD DETAILS FROM ANTI ARRHYTHMIC CARD
- class
- antimuscarinic/anticholinergic
- structure
- natural tertiary amine → crosses BBB
- uses
- symptomatic bradycardia (most potent increase in HR)
- PEA/Asystole
- combination with anticholinesterase for NMB reversal (edrophonium)
- antisialagogue
- bronchodilation
- mydriasis (pupil dilation)
- cycloplegia (paralysis of accomodation)
2
Q
atropine: MOA
A
- Competitive inhibition of Ach at muscarinic receptors of organs innervated by cholinergic postganglionic nerves
- blocking normal cholinergic tone allows sympthetic responses to dominate
- Increases HR by blocking acetylcholine effects on the SA node
- antagonizes histamine and serotonin
3
Q
atropine: PK
A
- Onset: 1 min
- DOA: 30-60 min
- E1/2: 2.3 hrs
- Vd: 1.6 L/kg
- PB: 40%, mostly to alpha-1 glycoprotein
- Metabolism: hydrolysis in the liver
- Elimination: 18% unchanged in the urine
4
Q
atropine: SE
A
-
NEURO:
- blurred vision (mydriasis and cycloplegia)
- increased IOP
- sedation
- (central anticholinergic syndrome) - crosses the BBB & can cause delirium, irritability, stupor, restlessness, disorientation, hallucinations, respiratory depression, & coma
-
CV:
- ↑ HR, CO, arrhythmias (PVC’s, AV dissociation)
-
PULM:
- dry mouth (xerostomia)
- bronchodilation
-
GI/GU:
- ↓GI motility and secretions
- urinary retention
-
SKIN:
- inhibits sweating
5
Q
atropine: cautions/contraindications/drug interations
A
- cautions/contraindications
- narrow angle glaucoma
- MG (unless used to treat side effects of AchE inhibitor)
- Elderly → CAS
- Pts where tachycardia would be harmful: thyrotoxicosis, pheochromocytoma, CAD
- Mobitz type II block
- GI obstruction/ileus
- avoid in hyperpyrexial patients because Atropine inhibits sweating
- Patients who have had heart transplants will be unaffected by antimuscarinics to increase HR
- drug interactions
- Anticholinergic medications (including phenothiazines and TCAs) may increase anticholinergic effects when used concurrently
- avoid using sympathomimetic amines concurrently → may cause tachyarrhythmias
6
Q
atropine: dose
A
- Bradycardia: 0.4-1.0 mg IV (max 3 mg)
- Pre-op antisialogogue: 0.2 to 0.4 mg IV 30-60 min prior.
- Combination w/ anticholinesterase to reverse paralytic: Atropine 7-15 mcg/kg co-administered with edrophonium 0.5 – 0.75 mg/kg
- Asystole, PEA: 1 mg q 3-5 min
- Bronchodilation: 2 mg in 5 cc NS via nebulizer
7
Q
glycopyrrolate: class + structure + use
A
- class
- synthetic anticholinergic/antimuscarinic agent
- structure
- quaternary ammonium → does not cross BBB (consider in elderly)
- uses
- preop antisialogogue - reduce salivary, tracheobronchial, & pharyngeal secretions & to reduce the volume & free acidity of gastric secretions (more potent than atropine)
- tx of vagal reflex bradycardia (Used to block cardiac vagal inhibitory reflexes during induction of anesthesia & intubation. Used intraoperatively for its moderate effects on inc. HR. Ideal for treating bradycardia resulting from airway manipulation, surgical manipulation, or anesthetic drugs → (less potent than atropine)
- NDNMB reversal with neostigmine - Used to antagonize muscarinic side effects during reversal of muscle relaxants w/anticholinesterase drugs
8
Q
glycopyrrolate: MOA
A
- Competitive inhibition of Ach at muscarinic receptors of organs innervated by cholinergic postganglionic nerves
- blocking normal cholinergic tone allows sympthetic responses to dominate
- Increases HR by blocking acetylcholine effects on the SA node
9
Q
glycopyrrolate: PK
A
- Onset: 2-3 min
- Peak: 3-5 min
- DOA: 2-4 hrs
- E1/2: 1.25 hrs
- Vd: 0.4 L/kg
- Poorly lipid soluble (quaternary ammonium structure)
- Elimination: 85% excreted unchanged in the urine
10
Q
glycopyrrolate: SE
A
-
NEURO:
- Blurred vision (mydriasis and cycloplegia)
- increased IOP
-
CV:
- ↑ HR, CO (moderate compared to atropine)
- tachydysrhythmias, AV dissociation, PVCs
-
PULM:
- dry mouth (xerostomia)
- bronchodilation
-
GI/GU:
- N/V, bloated feeling
- ileus
- constipation
- urinary retention
- ↓ secretions & GI motility
-
SKIN:
- decreased sweating, overheating in children and the elderly
11
Q
glycopyrrolate: cautions/contraindications
A
- Neonates and elderly
- Narrow angle glaucoma
- Myasthenia Gravis
- Pts where tachycardia would be harmful: thyrotoxicosis, pheochromocytoma, CAD
- Mobitz type II block
- GI obstruction/ileus
- Avoid in renal disease (renally excreted)
- Will not increase HR in heart TX
- DILUENT INCOMPATIBILITIES: Lactated Ringer’s solution; Pregnancy Cat. B
12
Q
glycopyrrolate: dose
A
- Antisialogogue & Bradycardia: 0.1-0.2 mg IV/IM/SC
-
Combination w/ anticholinesterase to reverse NDNMB
- Glycopyrrolate (.01 - .02 mg/kg) given with neostigmine (.05 - .07 mg/kg) OR
- 0.2 mg glycopyrrolate for each 1.0 mg of neostigmine IV in same syringe OR
- 0.01 mg/kg glycopyrrolate
13
Q
scopolamine: class + structure + use
A
- class
- anticholinergic/antimuscarinic
- structure
- natural tertiary amine → crosses BBB
- use
- sedation (most potent)
- antisialogogue (most potent)
- mydriasis and cycloplegia (most potent)
- bradycardia (least potent)
- motion induced N/V; N/V associated with anesthesia
- biliary and ureteral smooth muscle relaxation
- bronchodilation
14
Q
scopolamine: MOA
A
- Competitive inhibition of Ach at muscarinic receptors of organs innervated by cholinergic postganglionic nerves
- blocking normal cholinergic tone allows sympthetic responses to dominate
15
Q
scopolamine: PK
A
- Onset: 10 min
- DOA: 2 hrs
- E1/2: 4.5 hrs, although full recovery may take 3-7 days
- highly lipid soluble
- easily penetrates the BBB and placenta
- Metabolism: extensive metabolism in liver
- Elimination: 1% excreted unchanged in urine
19
Q
anticholinergic effect comparison (chart)
A
