Phospholine Iodide

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Phospholine Iodide

Classes

Other Miotics-Antiglaucoma Agents

Administration
Ophthalmic Administration

For topical application to the eye only.
Instruct patient on proper instillation of eye suspension.
Instruct patient to apply pressure to the inner corner of the eye for 1 to 2 minutes after instillation of the drops to help minimize drainage into the nose and throat, remove excess solution around the eyes with a tissue, and wash hands after use.

Extemporaneous Compounding-Ophthalmic

Compounding of Phospholine Iodide:
Use aseptic technique.
Tear off aluminum seals. Remove and discard rubber plugs from both drug and diluent containers.
Pour diluent into the drug container.
Unwrap and remove dropper. Holding the dropper by the screw cap, insert it into the drug container and screw down tightly without compressing the rubber bulb.
Shake for several seconds to mix the solution.

Adverse Reactions
Severe

ocular hypertension / Delayed / Incidence not known
retinal detachment / Delayed / Incidence not known
uveitis / Delayed / Incidence not known

Moderate

cataracts / Delayed / Incidence not known
myopia / Delayed / Incidence not known
blurred vision / Early / Incidence not known
respiratory depression / Rapid / Incidence not known
myasthenia / Delayed / Incidence not known
urinary incontinence / Early / Incidence not known
iritis / Delayed / Incidence not known

Mild

ocular irritation / Rapid / Incidence not known
lacrimation / Early / Incidence not known
headache / Early / Incidence not known
ocular pain / Early / Incidence not known
diarrhea / Early / Incidence not known
hyperhidrosis / Delayed / Incidence not known

Common Brand Names

Phospholine Iodide

Dea Class

Rx

Description

Ophthalmic cholinesterase-inhibitor miotic agent
Used in adults to decrease intraocular pressure; used in pediatric patients to diagnose and treat concomitant esotropias with a significant accommodative component
Contraindicated in patients with active uveal inflammation, angle-closure glaucoma without iridectomy, or a hypersensitivity to the drug

Dosage And Indications
For the treatment of increased intraocular pressure.
NOTE: Use is contraindicated in most cases of angle-closure glaucoma without iridectomy and in patients with active uveal inflammation.
Ophthalmic dosage Adults

1 drop instilled in the eye(s) twice daily, in the morning and at bedtime, is the preferred regimen; however, a change in therapy is indicated if the tension fails to remain at an acceptable level while on this regimen. May consider reducing the dose to 1 drop per day or every other day if needed.

For the diagnosis and treatment of strabismus of the accommodative esotropia type. For diagnosis of accommodative strabismus. Ophthalmic dosage Children and Adolescents

Instill 1 drop into both eyes once daily at bedtime for 2 for 3 weeks.

For the treatment of accommodative strabismus. Ophthalmic dosage Children and Adolescents

Initiate treatment using the lowest frequency that will give a satisfactory response. The maximum usual recommended dose is 1 drop daily, although more intensive therapy has been used for short periods. After the initial diagnostic period, the dose may be reduced to 1 drop every other day and gradually decreased as treatment progresses. Treatment may be continued for as long as the drug is tolerated. If tolerance develops, a rest period will restore the initial effect of the drug. If treatment is gradually withdrawn after 1 to 2 years and symptoms recur, surgery should be considered.

Dosing Considerations
Hepatic Impairment

Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed.

Renal Impairment

Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed.

Drug Interactions

There are no drug interactions associated with Echothiophate products.

How Supplied

Phospholine Iodide Ophthalmic Pwd F/Recon: 0.125%

Maximum Dosage
Adults

2 drops/day per affected eye.

Geriatric

2 drops/day per affected eye.

Adolescents

1 drop/day per affected eye.

Children

1 drop/day per affected eye.

Mechanism Of Action

Echothiophate is an indirect-acting parasympathomimetic agent. By interfering with the enzymatic destruction of acetylcholine, echothiophate potentiates the action of acetylcholine at cholinergic synapses. The pupil of the eye is constricted by contraction of the iris sphincter, producing miosis. Contraction of the ciliary muscle produces spasm of accommodation. In glaucoma, the intraocular pressure rises to an unacceptable level, producing pain and abnormal vision; if untreated, it can cause loss of sight. In open-angle glaucoma, echothiophate contracts the ciliary muscle and widens the trabecular meshwork, increasing the outflow of aqueous humor, which reduces intraocular pressure. In closed-angle glaucoma, echothiophate-induced miosis relieves the blockage of the trabecular meshwork by the peripheral iris, allowing the anterior chamber of aqueous humor to enter.

Pharmacokinetics

Echothiophate is administered topically to the eye. Echothiophate is protein-bound in blood and tissues and oxidized and hydrolyzed in tissues by phosphorylphosphatases. The drug is excreted almost entirely as metabolites in the urine.

Other Route(s)

Ophthalmic Route
A decrease in pressure occurs within 4 hours after application, with maximal effect achieved within 24 hours. Miosis occurs within an hour of application and peaks within 2 hours. Echothiophate penetrates into ocular tissue through the cornea, the amount varying according to a number of factors. Systemic absorption through the conjunctiva and lacrimal drainage system can produce parasympathomimetic effects. Following ophthalmic application of echothiophate, systemic anticholinesterase activity is detectable within a few minutes. Repeated administration will cause decreased cholinesterase concentrations in both plasma and erythrocytes in most patients. Application of finger pressure to the inner canthus for 1—2 minutes following instillation of the drops is important in reducing the amount of drug systemically absorbed.

Pregnancy And Lactation
Pregnancy

The use of echothiophate during pregnancy has not been evaluated. It is unknown if the drug can cause fetal harm or affect reproductive capacity. Administer echothiophate during pregnancy only if clearly needed.

It is not known whether echothiophate is excreted in human milk. Although the extent of absorption is unclear, chronic use of echothiophate ophthalmic solution may have systemic effects which indicates some degree of absorption occurs. According to the manufacturer, because many drugs are excreted in human milk, and because of the potential for serious adverse reactions from echothiophate, a decision should be made whether to discontinue breast-feeding or to discontinue the drug, taking into account the importance of the drug to the mother. To minimize the amount of drug that reaches systemic circulation and breast milk, apply pressure over the tear duct by the corner of the eye for 1 minute after each topical application. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally administered drug, health care providers are encouraged to report the adverse effect to the FDA.