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Echothiophate Iodide

Generic name: echothiophate iodide ophthalmic

Brand names: Phospholine Iodide

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Solution Reconstituted, Ophthalmic:

Phospholine Iodide: 0.125% (5 mL)


Mechanism of Action

Long-acting inhibition of cholinesterase enhances activity of endogenous acetylcholine. Reduced degradation of acetylcholine leads to continuous stimulation of the ciliary muscle producing miosis; other effects include potentiation of accommodation and facilitation of aqueous humor outflow, with attendant reduction in intraocular pressure.


Onset of Action

Miosis: ≤60 minutes; Peak effect: Intraocular pressure decrease: 24 hours

Duration of Action

Miosis: 1 to 4 weeks; Intraocular pressure: Days to weeks.

Use: Labeled Indications

Accommodative esotropia: Concomitant esotropias with a significant accommodative component

Elevated intraocular pressure: Reduction of elevated intraocular pressure


Hypersensitivity to echothiophate or any component of the formulation; most cases of angle-closure glaucoma without iridectomy (due to possibility of increasing angle block); active uveal inflammation

Dosage and Administration

Dosing: Adult

Elevated intraocular pressure: Ophthalmic:

Initial: Instill 1 drop in affected eye(s) twice daily (prior to bedtime and in the morning)

Maintenance: Twice-daily dosing is preferred, but some patients have been treated with once-daily or every-other-day dosing (with 1 dose just prior to bedtime).

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Esotropia, accommodative: Children and Adolescents: Ophthalmic:

Diagnosis: Instill 1 drop once daily into both eyes at bedtime for 2 to 3 weeks

Treatment: Instill 1 drop every other day in both eyes; gradually lower dose as treatment progresses. Maximum daily dose: 1 drop once daily in both eyes. Note: Use lowest frequency which gives satisfactory response; if necessary, more aggressive therapy may be used for short periods of time.


Pour diluent into drug container; without compressing rubber bulb, insert dropper assembly into drug container and screw down tightly. Shake well to ensure mixing.


Ophthalmic: Proper administration technique is required for maximal benefit. The nasolacrimal duct(s) should be compressed for 1 to 2 minutes after instillation of the drops. Excess fluid around the eye should be blotted with tissue; wash hands after instillation.


Store undiluted vials at 2°C to 8°C (36°F to 46°F). Store reconstituted solutions at ~25°C (~77°F); do not refrigerate; discard unused solution after 4 weeks.

Drug Interactions

Cyclopentolate: May diminish the therapeutic effect of Echothiophate Iodide. Monitor therapy

Mivacurium: Echothiophate Iodide may increase the serum concentration of Mivacurium. Monitor therapy

Succinylcholine: Echothiophate Iodide may increase the serum concentration of Succinylcholine. Management: For patients receiving echothiophate iodide eye drops, consider using a neuromuscular-blocking agents other than succinylcholine. If succinylcholine is used, consider a reduced dose, and monitor for enhanced/prolonged effects. Consider therapy modification

Adverse Reactions

Frequency not defined.

Cardiovascular: Bradycardia, cardiac abnormality, flushing, hypotension

Central nervous system: Brow ache, myasthenia

Dermatologic: Diaphoresis

Gastrointestinal: Diarrhea, nausea, vomiting

Ophthalmic: Blepharospasm, blurred vision, burning sensation of eyes, cataract, conjunctival abnormalities (thickening), conjunctival erythema, eye redness, increased intraocular pressure (paradoxical), iris cyst, iritis (latent), lacrimal duct obstruction (nasolacrimal canal), lacrimation, miosis, myopia, retinal detachment, stinging of eyes, uveitis (activation)

Respiratory: Dyspnea


Concerns related to adverse effects:

  • Cardiac irregularities: Temporarily or permanently discontinue if cardiac irregularities occur.
  • Cholinergic effects: Discontinue if symptoms of excess cholinergic activity (eg, salivation, sweating, urinary incontinence); overdosage may result in cholinergic crisis, which must be distinguished from myasthenic crisis.

Disease-related concerns:

  • Asthma: Not generally recommended for use in patients with asthma.
  • Cardiovascular disease: Not generally recommended for use in patients with bradycardia, hypotension or recent MI. In a scientific statement from the American Heart Association, ophthalmic cholinergic agents have been determined to be agents that may exacerbate underlying myocardial dysfunction (magnitude: minor) (AHA [Page 2016]).
  • Gastrointestinal disease: Not generally recommended for use in patients with spastic gastrointestinal disturbances or peptic ulcer disease.
  • Parkinsonism: Not generally recommended for use in patients with Parkinsonism.
  • Seizure disorder: Not generally recommended for use in patients with a history of seizure disorder.
  • Vagotonia: Not generally recommended for use in patients with vagotonia.

Concurrent drug therapy issues:

  • Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Other warnings/precautions:

  • Appropriate use: Do not use for tonometric glaucoma, or in patients with active or history of uveitis, or history of retinal detachment. Use cautiously prior to ophthalmic surgery due to risk of blood in the anterior chamber. Digital compression of the nasolacrimal ducts for 1 to 2 minutes following instillation to minimize drainage into the nasal chamber is recommended. Wash hands following instillation.
  • Exposure to pesticides and insecticides: Use with caution in patients exposed to carbamate- or organophosphate-type insecticides and pesticides; absorption of the pesticide through skin or respiratory tract may result in additive systemic effects; respiratory masks and frequent clothing changes may be necessary during exposure to pesticides in patients receiving echothiophate iodide.
  • Tolerance: Patients may develop tolerance after prolonged use; a rest period restores response to the drug.

Monitoring Parameters

Baseline measurement of anterior chamber angle; routine lens examinations (for opacities and during treatment of accommodative esotropia); IOP (at different times of the day)


Pregnancy Considerations

Animal reproduction studies have not been conducted.

Patient Education

  • Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
  • Patient may experience burning, stinging, blurred vision, headache, eye redness, eyelid twitching, or watery eyes. Have patient report immediately to prescriber vision changes, eye pain, severe eye irritation, fast heartbeat, slow heartbeat, abnormal heartbeat, diarrhea, bladder incontinence, drooling, muscle weakness, sweating a lot, or shortness of breath (HCAHPS).
  • Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

Source: Wolters Kluwer Health. Last updated October 1, 2019.