Emergency Drugs

Question 0

Phenylephrine: Class, Action, and Indication

Answer 0

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)

Question 1

Phenylephrine: dilution

Answer 1

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)

Question 2

Phenylephrine: Dose, Onset, Duration of Action, Metabolism

Answer 2

Dose: 50-200mcg (continuous infusion of 20-50mcg/min)
Onset: immediate
Duration of Action: 5-20 min
Metabolism: hepatic

Question 3

Phenylephrine differences from norepinephrine

Answer 3

Phenylephrine is less potent and longer lasting

Question 4

Ephedrine: dilution

Answer 4

50mg/mL vial

Dilute in 5mL syringe for 10mg/mL OR dilute in 10mL syringe for 5mg/mL

Question 5

Ephedrine: Class, Action, and Indication

Answer 5

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

Question 6

Ephedrine: Dosage, Onset, Duration

Answer 6

Dosage: 5-25 mg IV/IM
Onset: immediate
Duration: 10-60 min

Question 7

Ephedrine: Metabolism, Cautions

Answer 7

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)

Question 8

Phenylephrine vs. ephedrine: Which do you not give to someone taking betablockers, which do you not give to someone on MAOIs or TCAs?

Answer 8

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

Question 9

You need to give a pregnant women one of the emergency drugs because she is hypotensive, which do you give? (phenylephrine or ephedrine)

Answer 9

Ephedrine

Question 10

Phenylephrine vs. Ephedrine: which works indirectly/directly, which is has more work on the heart, which one increases/decreases HR

Answer 10

Phenylephrine: directly (ephedrine indirect)
Phenylephrine is more work on the heart (harder for elderly people)
Phenylephrine decreases HR
Ephedrine increases HR

Question 11

Atropine: dilution/preporation

Answer 11

0.4-1 mg/mL
1mg total, 3mL syringe
NO dilution

Question 12

Atropine: class, mechanism of action, indication

Answer 12

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

Question 13

Atropine: dose, onset, duration, metabolism

Answer 13

Dose: 15-75 mcg/kg or 0.4-1mg for adults
Onset: immediately
Duration: 1-2 hours
Metabolism: hepatic

Question 14

Succinylcholine: preparation/dilution

Answer 14

20mg/mL in 10mL syringe

No dilution, straight from vial

Question 15

Succinylcholine: class, mechanism of action, indications

Answer 15

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

Question 16

Succinylcholine: dose, onset, duration of action, metabolism

Answer 16

Dose: 20-40mg IV/IM (for laryngospasm), (1mg/kg for intubation)
Onset: 30-60 sec
Duration: 3-5 min
Metabolism: plasma cholinesterases

Question 17

Succinylcholine: side effects

Answer 17

Dysrhythmias (brady, junctional, ventricular), hyperkalemia, fasciculations, myalgia, increased GI pressure, increased ICP, increased IOP, masseter spasm, histamine release, malignant hyperthermia

Question 18

Difference between atropine and glycopyrrolate (Rubinul)

Answer 18

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

Question 19

labetalol: class, dose, duration of action

Answer 19

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)

Question 20

labetalol: contraindications

Answer 20

contraindications: avoid in asthmatics (bc bronchoconstriction), make sure HR is normal before giving

Question 21

If intubating a patient with CAD, which beta blocker would you use?

Answer 21

Esmolol

Question 22

Esmolol: dose, onset, duration of action

Answer 22

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

Question 23

Metoprolol: side effects, dose

Answer 23

It crosses the BBB, so CNS depression
Dose: 1mg/mL, only give 1mg at a time
B1 blocker