Emergency Drugs Flashcards
Phenylephrine: Class, Action, and Indication
Class: synthetic non-catecholamine
Action: alpha1-adrenergic receptor stimulant
Intense vasoconstriction (veno>art), Increased systolic and diastolic BP, increased SVR, reflex bradycardia
Indication: hypotension, sympathectomy (but not for OB)
Phenylephrine: dilution
10mg/mL vial
Dilution in 100mL bag of saline per one vial OR
Double dilution: dilute vial in 10mL syringe (now it is 1mg/1mL), discard 9mg, dilute again with 9mL (now its 0.1mg/1mL=100mcg/1mL)
Phenylephrine: Dose, Onset, Duration of Action, Metabolism
Dose: 50-200mcg (continuous infusion of 20-50mcg/min)
Onset: immediate
Duration of Action: 5-20 min
Metabolism: hepatic
Phenylephrine differences from norepinephrine
Phenylephrine is less potent and longer lasting
Ephedrine: dilution
50mg/mL vial
Dilute in 5mL syringe for 10mg/mL OR dilute in 10mL syringe for 5mg/mL
Ephedrine: Class, Action, and Indication
Class: Synthetic non-catecholamine
Action: indirect beta and alpha adrenergic stimulant (stimulate vesicles to release catecholamines to work on these receptors)
Vasoconstriction, increased systolic and diastolic BP (minimal SVR change), increased contractility, increased HR, bronchodilation
Indication: hypotension, OK to use for OB patients
Ephedrine: Dosage, Onset, Duration
Dosage: 5-25 mg IV/IM
Onset: immediate
Duration: 10-60 min
Ephedrine: Metabolism, Cautions
Metabolism: hepatic, renal
Cautions: pt taking MAOI’s, traumas and repeated dosing can cause tachyphylaxis (they get used to the drug and it becomes ineffective)
Phenylephrine vs. ephedrine: Which do you not give to someone taking betablockers, which do you not give to someone on MAOIs or TCAs?
Phenylephrine should not be given to patients on beta blockers (bc when alpha is stimulated and beta is blocked, the heart will not pump efficiently)
Don’t give ephedrine to patients on MAOIs/TCAs because they have too many presynaptic catecholamines (ephedrine stimulates release of catecholamines from vesicles), causing these to be released would be dangerous
You need to give a pregnant women one of the emergency drugs because she is hypotensive, which do you give? (phenylephrine or ephedrine)
Ephedrine
Phenylephrine vs. Ephedrine: which works indirectly/directly, which is has more work on the heart, which one increases/decreases HR
Phenylephrine: directly (ephedrine indirect)
Phenylephrine is more work on the heart (harder for elderly people)
Phenylephrine decreases HR
Ephedrine increases HR
Atropine: dilution/preporation
0.4-1 mg/mL
1mg total, 3mL syringe
NO dilution
Atropine: class, mechanism of action, indication
Class: anticholinergic, Indication: Bradycardia
Action: antagonizes Ach at muscarinic receptor, Structure: tertiary amine
Antagonizes Ach (by preventing it from binding to muscarinic receptor.. works on Parasympathetic) increase HR, decrease secretions (gastric, mucous), relax bronchial smooth muscle, reduce GI tone/motility, decrease esophageal sphincter pressure, mydriasis (pupils dilate), urine retention, crosses BBB so sedation, nervousness, confusion, hallucinations, delirium, coma
Atropine: dose, onset, duration, metabolism
Dose: 15-75 mcg/kg or 0.4-1mg for adults
Onset: immediately
Duration: 1-2 hours
Metabolism: hepatic
Succinylcholine: preparation/dilution
20mg/mL in 10mL syringe
No dilution, straight from vial
Succinylcholine: class, mechanism of action, indications
Class: depolarizing muscle relaxant
Action: It attaches to alpha subunits of nicotinic cholinergic receptor and mimics acetylcholine, depolarizing postsynaptic neuromuscular membrane, but it hydrolyzes slower than Ach creating sustained paralysis of the receptor channels (it causes fasciculation then paralyzes)
Indication: vocal cord paralysis for intubation or treatment of laryngospasm
Succinylcholine: dose, onset, duration of action, metabolism
Dose: 20-40mg IV/IM (for laryngospasm), (1mg/kg for intubation)
Onset: 30-60 sec
Duration: 3-5 min
Metabolism: plasma cholinesterases
Succinylcholine: side effects
Dysrhythmias (brady, junctional, ventricular), hyperkalemia, fasciculations, myalgia, increased GI pressure, increased ICP, increased IOP, masseter spasm, histamine release, malignant hyperthermia
Difference between atropine and glycopyrrolate (Rubinul)
Glycopyrrolate: doesn’t cross BBB so no sedative effects (atropine shouldn’t be given in dementia patients, it does cross BBB), more potent antisialagogue, less potent at increasing HR, dosage is 0.2-0.4mg IV, and it is combined with an anticholinesterase to reverse muscle relaxant, also it doesn’t work immediately like atropine does, it takes a few minutes
labetalol: class, dose, duration of action
class: nonselective beta blocker (with small alpha effect)
dose: 0.25mg/kg (start with bolus 5-10mg)
duration: 2-18 hours (tell PACU if it has been given)
labetalol: contraindications
contraindications: avoid in asthmatics (bc bronchoconstriction), make sure HR is normal before giving
If intubating a patient with CAD, which beta blocker would you use?
Esmolol
Esmolol: dose, onset, duration of action
Dose: pushes of 10-15mg (or bolus then drip) Onset: 2 min Duration: 9 min So this is a very quick acting drug B1 blocker
Metoprolol: side effects, dose
It crosses the BBB, so CNS depression
Dose: 1mg/mL, only give 1mg at a time
B1 blocker
