echothiophate iodide (Phospholine Iodide)

Dosing and uses of Phospholine Iodide (echothiophate iodide)

• Adult
• Pediatric

 

Adult dosage forms and strengths

ophthalmic solution

• 0.125%

 

Open Angle or Secondary Glaucoma

Initial: 0.03% solution instilled in affected eye(s) twice daily (AM & HS); may use higher dose (>0.06%) if unsatisfactory response

Maintenance: 1 dose every other day

 

Advanced Chronic Simple Glaucoma/Glaucoma Following Cataract Surgery

Initial 0.03% instilled in affected eye(s) twice daily

Higher strengths usu necessary if transferred after unsatisfactory response with other drugs

 

Pediatric dosage forms and strengths

ophthalmic solution

• 0.125%

 

Accommodative Esotropia

Initial (Dx): 0.125% solution instilled in both eyes qHS for 2-3 weeks

Maintenance (if Dx+)

• 0.125% solution qOTHERday
• May be gradually lowered

 

Phospholine Iodide (echothiophate iodide) adverse (side) effects

Frequency not defined

Burning

Bradycardia

Flushing

Hypotension

Stinging

Lacrimation

Iris cyst formation

Diarrhea

Nausea

Vomiting

Blurred vision

Ciliary redness

Increased intraocular pressure

Miosis

Myopia

Uveitis activation

Lens opacities

Retinal detachment

Lid muscle twitching

 

Warnings

Contraindications

Hypersensitivity

Active uveitis

Angle clossure glaucoma

Relative: history of retinal detachment; quiescent/history of uveitis

 

Cautions

Caution in marked vagotonia, bronchial asthma, spastic GI disturbances, peptic ulcer, pronounced bradycardia & hypotension, recent MI, epilepsy, parkinsonism

Concomitant cholinergic drugs (succinylcholine, systemic myasthenia gravis drugs)

Potential for conjunctival thickening, retinal detachment, lens opacity

Discontinue if cholinergic side-effects occur (hyperhidrosis, sialorrhea, urinary incontience, diarrhea etc) or cardiac irregularities

Do not use more frequently than q12hr

Few weeks of therapy may depress plasma and erythrocyte cholinesterase levels

Perform baseline measurement of anterior chamber angle and perform routine lenss examination; do not use for tonometric glaucoma, or with active history of uveitis

 

Pregnancy and lactation

Pregnancy category: C

Lactation: Discontinue drug or do not nurse

 

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 Phospholine Iodide (echothiophate iodide)

Mechanism of action

Cholinesterase inhibitor; enhances activity of endogenous acetylcholine, which leads to continuous stimulation of the ciliary muscle producing miosis and fascilitation of humor outflow that may reduce intraocular pressure

 

Pharmacokinetics

Onset of action: 10-30 min (miosis); 4-8hr (IOP); 24 hr (peak effects IOP)

Duration: 1-4 weeks (miosis)