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STUDY GUIDE #1: REVERSAL AGENTS= ANTIMUSCLE RELAXANTS
Reversal Agents
A reversal agent is any drug used to reverse the effects of anesthetics, narcotics or potentially toxic agents. Examples: Antilirium,
digibind, mestinon, narcan, neostigmine, protopam, pyridostigmine, romazicon, tensilon.
As patients emerge from anesthesia, they need to breathe autonomously, swallow normally, cough and clear lung secretions, and sit
up. To do these things, almost all the effects of neuromuscular blockers must be gone. However, on their own, muscle relaxants wear
off slowly. Therefore, after surgery, the anesthesiologist usually gives an "anti-muscle relaxant," a reversal agent. Reversal agents—
anticholinesterases such as edrophonium (Enlon), neostigmine (Prostigmine), and pyridostigmine (Mestinon)—increase the signaling
effect of the body's acetylcholine by slowing its normal breakdown.
Reversal agents are effective at speeding up patients' abilities to uses their muscles. Unfortunately, the reversal agents can cause their
own side effects: bradycardia, narrowing of the bronchi, contraction of intestinal muscles, and excess salivary and bronchial
secretions. These side effects are caused by stimulation of the muscarinic form of the cholinergic receptors, while the reversal effects
are cause by stimulation of the nicotinic form of the cholinergic receptors. Therefore, the unwanted side effects can be selectively
blocked by administering muscarinic anticholinergic drugs (atropine or glycopyrrolate) along with the reversal agent.
Drug side effects can be reported to the FDA at 1-800-FDA-1088
DRUG
DRUG INFO
0.4 mg/ml
ATROPINE
amine anticholinergic
DOSE: 15-70mcg/kg
ONSET: 15-30 s
PEAK: 2 m
DURATION: 1-2 hrs
REVERSAL AGENT FOR
2
DRUG
DRUG INFO
REVERSAL AGENT FOR
0.2 mg/ml
ROBINUL
(glycopyrrolate)
anticholinergic
NARCAN
(naloxone)
-ENLON
(TENSILON)=(Plain
Enlon, without Atropine)
DOSE: 10-20 mcg/kg
ONSET: 1m
PEAK: 5m
DURATION: 2-4hrs
0.4 mg/ml
-OPIOID ANTAGONIST (EX. Morphine; Versed
[Midazoliam] )
DOSE: 1-10mcg/kg
ONSET: 1-2m
PEAK: 5-15m
DURATION: 1-4hrs
-ANTICHOLINESTERASE
10mg/ml
DOSE: 0.5-1 mg/kg
ONSET: 30-60s
PEAK: 1-5m
-ENLON PLUS=
(Edrophonium + atropine); DURATION: 5-20m
- Edrophonium is indicated to reverse the
neuromuscular blockade produced by many
nondepolarizing agents, including atracurium,
gallamine, metocurine, mivacurium, pancuronium,
rocuronium, tubocurarine, and vecuronium
0.5-1 mg/ml
PROSTIGMINE
(neostigmine)
-ESTER ANTICHOLINESTERASE
DOSE: 0.04-0.07MG/KG
ONSET: 1-3m
PEAK: 5-7m
DURATION: 40-60m
3
DRUG
REGONAL OR
MESTINON
(pyridostigmine)
ROMAZICON
(flumazenil)
DRUG INFO
5 mg/ml
DOSE: 0.1-0.25mg/kg
ONSET: 2-5m
PEAK: 5-15m
DURATION: 90m
1 mg/ml
REVERSAL AGENT FOR
-ESTER
ANTICHOLINESTERASE
-BENZODIAZEPINE ANTAGONIST
DOSE:8-15 mcg/kg, 0.2mg typical adult
ONSET: 1-2m
PEAK: 6-10m
DURATION: 30-60m
Protamine sulphate neutralizes the anticoagulant
action of heparin: before surgery; after renal
dialysis; after open-heart surgery, if excessive
bleeding occurs and when an overdose has
inadvertently been given.
PROTAMINE SULFATE
Below (pg. 4) is a list of reversal drugs not
commonly used in the O.R.
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DRUG
PHYSOSTIGMINE
(ANTILIRIUM)
DIGIBIND (digoxin
immune FAB)
DRUG INFO
REVERSAL AGENT FOR
Physostigmine is used to reverse CNS effects
resulting from clinical or toxic dosages of drugs
(e.g., some antihistamines, antimuscarinics,
0.5–2 mg; may repeat dose every 20 minutes until antiparkinsonian agents, phenothiazines) capable of
response occurs or adverse cholinergic effects occur. producing anticholinergic syndrome and from
intoxication with certain plants (e.g., Atropa
belladonna [deadly nightshade], Brugmansia
species [angels’ trumpet], Datura stramonium
[jimsonweed, thorn apple, locoweed], Lantana
camara.
Digoxin immune FAB is used as an antidote to treat
a life-threatening overdose of digoxin or digitoxin.
IV:
PROTOPAM
(Pralidoxime chloride)
Information Source: http://www.drugs.com/
(2011)
In the US, Pralidoxime (pralidoxime systemic) is a
member of the drug class antidotes and is used to
treat anticholinesterase overdose, nerve agent
poisoning and organophosphate poisoning (some
pesticides).