Tensilon

edrophonium

(e-droh-fone-ee-yum) ,

Enlon

(trade name),

Tensilon

(trade name)

Classification

Therapeutic: antidotes
Pharmacologic: anticholinesterases
Pregnancy Category: C

Indications

Diagnosis of myasthenia gravis.Assessment of adequacy of anticholinesterase therapy in myasthenia gravis.Differentiating myasthenic from cholinergic crisis.Reversal of muscle paralysis from nondepolarizing neuromuscular blocking agents.

Action

Inhibits the breakdown of acetylcholine so that it accumulates and has a prolonged effect. Effects include miosis; increased intestinal and skeletal muscle tone; bronchial constriction; bradycardia; increased salivation, lacrimation, and sweating.

Therapeutic effects

Short-lived improvement in muscular function in patients with myasthenia gravis.
Reversal of nondepolarizing neuromuscular blocking agents.

Pharmacokinetics

Absorption: Absorption following IM and subcut administration not known.
Distribution: 1.1 L/kg.
Metabolism and Excretion: Unknown.
Half-life: 73–126 min.

Time/action profile (cholinergic activity)

ROUTEONSETPEAKDURATION
IM2–10 minunknown5–30 min
IV30–60 secunknown10 min

Contraindications/Precautions

Contraindicated in: Hypersensitivity; Mechanical obstruction of the GI or GU tract; Hypersensitivity to bisulfites; Obstetric: May cause uterine irritability after IV administration near term; newborns may display muscle weakness; Lactation: Lactation.
Use Cautiously in: History of asthma; Cardiovascular disease; Because some patients may be extremely sensitive to the effects of anticholinesterases, atropine should be available in case of excessive dosage.

Adverse Reactions/Side Effects

Central nervous system

  • seizures (life-threatening)
  • dizziness
  • dysphasia
  • dysphonia
  • weakness

Ear, Eye, Nose, Throat

  • diplopia
  • lacrimation
  • miosis

Respiratory

  • bronchospasm (most frequent)
  • excess secretions (most frequent)

Cardiovascular

  • bradycardia (most frequent)
  • hypotension

Gastrointestinal

  • abdominal cramps (most frequent)
  • diarrhea (most frequent)
  • dysphagia
  • excess salivation (most frequent)
  • vomiting (most frequent)
  • nausea

Genitourinary

  • incontinence
  • urinary frequency

Dermatologic

  • sweating (most frequent)
  • rashes

Musculoskeletal

  • fasciculation

Interactions

Drug-Drug interaction

Action may be antagonized by drugs possessing anticholinergic properties, including antihistamines, antidepressants, atropine, haloperidol, phenothiazines, quinidine, and disopyramide.Prolongs action of depolarizing muscle-relaxing agents (succinylcholine, decamethonium ).May lead to ↑ bradycardia in patients receiving digoxin.Angel's trumpet, jimson weed, and scopolia may antagonize cholinergic effects.

Route/Dosage

Diagnosis of Myasthenia Gravis
Intravenous (Adults) 2 mg; if no response, administer an additional 8 mg after 45 sec; may repeat test in 30 min. If cholinergic response occurs after initial 2 mg dose, administer atropine 0.4–0.5 mg IV. Patients >50 yr should be pretreated with atropine to prevent bradycardia/hypotension.
Intravenous (Children >34 kg) 2 mg; if no response after 45 sec, may administer 1 mg every 30–45 sec to a total of 10 mg.
Intravenous (Children <34 kg) 1 mg; if no response after 45 sec, may administer 1 mg every 45 sec to a total of 5 mg.
Intravenous (Infants) 0.5 mg.
Intramuscular (Adults) 10 mg. If cholinergic response occurs, may repeat 2-mg dose in 30 min to rule out false-negative reaction. Patients >50 yr should be pretreated with atropine to prevent bradycardia/hypotension.
Intramuscular (Children >34 kg) 5 mg.
Intramuscular (Children <34 kg) 2 mg.
Assessment of Anticholinesterase Therapy
Intravenous (Adults) 1–2 mg 1 hr after oral anticholinesterase dose.
Differentiation of Cholinergic from Myasthenic Crisis
Intravenous (Adults) 1 mg; may give additional 1 mg 1 min later.
Reversal of Nondepolarizing Neuromuscular Blocking Agents
Intravenous (Adults) 10 mg; may repeat as needed (not to exceed 40 mg). Doses of 0.5–1 mg/kg have been used.

Availability

Injection: 10 mg/mL
In combination with: atropine (Enlon-Plus). (See combination drugs).

Nursing implications

Nursing assessment

  • Assess neuromuscular status (ptosis, diplopia, vital capacity, ability to swallow, extremity strength) prior to and immediately after administration.
    • Reversal of nondepolarizing neuromuscular blocking agents is more rapid in pediatric patients.
    • To differentiate myasthenic from cholinergic crisis, assess for increased weakness, diaphoresis, increased saliva and bronchial secretions, dyspnea, nausea, vomiting, diarrhea, and bradycardia. If these symptoms occur after administration of edrophonium, patient is in cholinergic crisis. If strength improves after administration of edrophonium, patient is in myasthenic crisis.
  • Atropine may be used for treatment of cholinergic symptoms. Oxygen and resuscitation equipment should be available.

Potential Nursing Diagnoses

Ineffective breathing pattern (Indications)

Implementation

  • For myasthenia gravis patients, diagnostic IV dose and dose to differentiate myasthenic from cholinergic crisis should be administered by a physician.
  • Intravenous Administration
  • Diluent: Administer undiluted with a tuberculin syringe. Concentration: 10 mg/mL.
  • Rate: Administer doses over 30–45 sec.
  • Y-Site Compatibility: heparin, hydrocortisone, potassium chloride, vitamin B complex with C

Patient/Family Teaching

  • Inform patient that the effects of this medication last up to 30 min.

Evaluation/Desired Outcomes

  • Relief of myasthenic symptoms.
  • Differentiation of myasthenic from cholinergic crisis.
  • Reversal of paralysis after anesthesia.

Tensilon

a trademark for an anticholinesterase drug (edrophonium).

Tensilon®

Edrophonium chloride Pharmacology A short-acting anticholinesterase used to diagnose myasthenia gravis and reverse the effects of nondepolarizing neuromuscular blockers. See Myasthenia gravis, Reversal agent.

Tensilon

trademark for edrophonium chloride; used in the diagnosis of myasthenia gravis, known as the Tensilon test.
References in periodicals archive ?
Because of the fact that many of these symptoms may present with GBS as well, myasthenia gravis will need to be ruled out through testing such as electromyography, Tensilon testing, and an assay for Ach-receptor binding antibodies.
2) Tensilon (edrophonium) has not been available in SA for some time, and neostigmine (intramuscular delivery) may be used instead.
Tensilon (3 hydroxy-phenyl dimethyl ethyl ammonium bromide, or edrophonium) was selected from a group of compounds as the one possessing the greatest anticholinergic activity and the least muscarinic effect.
A provisional diagnosis of MG was given to the patient and this was later confirmed through a positive tensilon test and a positive blood test for ACH antibodies.
The diagnosis is primarily made using the Tensilon test.
The results of repetitive stimulation and Tensilon testing were normal.
Levo-Dromoran is a medication for the management of severe pain and Tensilon is used for the treatment of myesthenia gravis.
She will very likely have a difficult time finding someone who will take her seriously and do the Tensilon test, but she should not stop until she does.
Tensile properties of the specimens were measured with an Orientec Tensilon RTC-1250A tensile tester.
Laryngeal electromyography showed a 20% decreased recruitment response in the left cricothy-roid muscle, which did not improve with Tensilon (edrophonium chloride) testing.
The two additional products acquired in this transaction are Tensilon for the treatment of myesthenia gravis and Levo-Dromoran for severe pain management.