Dosing and uses of Enlon, Enlon Plus (edrophonium)
Adult dosage forms and strengths
injectable solution
- 10mg/mL
Myasthenia Gravis, Diagnosis
2 mg IV push over 15-30 seconds
If muscarinic side effects, fasciculations, & increased muscle weakness occur, discontinue test & give 0.4-0.5 mg atropine IV
If no response, give 8 mg after 45 seconds
May repeat test 30 minutes later
Reversal of Nondepolarizing Neuromuscular Blockers
10 mg IV over 30-45 sec q5-10min PRn
Not to exceed 40 mg
Terminate Paroxysmal Atrial Tachycardia
10 mg IV bolus into IV infusion line (5-7 mg in elderly/digitalized patients)
Pediatric dosage forms and strengths
injectable solution
- 10mg/mL
Myasthenia Gravis, Diagnosis
Infants
- 0.5-1 mg IM
- 0.1 mg followed by 0.4 mg if no response; not to exceed 0.5 mg
Children
- Initial: 0.04 mg/kg IV x1 (no more than 5 mg for <34 kg, 2 mg for >34 kg)
- If no response after 1 minute: 0.16 mg/kg IV x1
- Total dose should not exceed 0.5 mg for infants, 5 mg for <34 kg; 10 mg for >34 kg
Enlon, Enlon Plus (edrophonium) adverse (side) effects
Less severe & more short-lived than other cholinergic drugs
Frequency not defined
Nausea/vomiting
Increased peristalsis
Increased salivation
Urinary urgency
Weakness
Muscle cramps
Lacrimation/small pupils
Hypotension
Arrhythmia
Bradycardia
Laryngospasm
Cardiac standstill (rare)
Warnings
Contraindications
Hypersensitivity (some experts state may be used in small amounts w/ atropine)
GI & urinary obstructions
Cautions
Use caution in epilepsy, asthma, recent MI, hyperthyroidism, arrhythmias, peptic ulcer, patients receiving cardiac glycosides
Pregnancy (possible risk of uterine irritability & premature labor)
May be of limited usefulness in surgery due to brief duration
Higher doses should be preceded by atropine
Use in myathenia gravis may exacerbate muscle weakness
Risk of cholinergic crisis with overdose, which can be fataL
Does not antagonize, & in fact may prolong, phase I muscle relaxation by depolarizing neuromuscular blockers (eg, succinylcholine)
Pregnancy and lactation
Pregnancy category: C
Lactation: Excretion in milk unknown
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Enlon, Enlon Plus (edrophonium)
Mechanism of action
Inhibits destruction of acetylcholine by cholinesterase; facilitates transmission of impulses across myoneural function, which results in increased cholinergic responses such as miosis
Phamacokinetics
Onset: 30-60 sec (IV); 2-10 min (IM)
Duration: 10 min (IV); 5-30 min (IM)
Vd: 1.1 L/kg
Half-life:1.2-2.4 hr (adults); 2.4-4.4 hr (anephric patients)
Excretion: Urine
Administration
IV Compatibilities
Y-site: heparin, hydrocortisone Na-succinate, KCl, Vit B/C
IV Administration
IV push
For off-label use in cardiac arrhythmias, has been infused at 0.25-2 mg/min
