Why is latanoprost (prostaglandin F2 alpha analogue) held in a patient with stroke-like symptoms?

Latanoprost and Stroke-Like Symptoms: Clinical Rationale

Latanoprost is held in patients with stroke-like symptoms because prostaglandin analogues can cause retinal vascular complications including retinal artery embolus, retinal detachment, and vitreous hemorrhage, which may mimic or complicate the neurological assessment of acute stroke. 1

Primary Safety Concerns

Retinal Vascular Events

• The FDA label for latanoprost documents "extremely rare reports" of retinal artery embolus, retinal detachment, and vitreous hemorrhage during clinical studies 1
• These retinal vascular events can present with sudden vision loss that may be confused with stroke-related visual symptoms or represent concurrent vascular pathology 1
• In patients with diabetic retinopathy specifically, vitreous hemorrhage risk is documented with latanoprost use 1

Macular Edema Risk

• Cystoid macular edema is a recognized adverse effect of latanoprost, occurring both during clinical trials and in post-marketing surveillance 1
• Macular edema can cause acute vision changes that complicate the neurological examination of stroke patients 1, 2
• Isolated cases of cystoid macular edema have been reported, requiring full investigation of any patient complaining of reduced vision while using the drug 2

Clinical Decision Algorithm

When to Hold Latanoprost

Immediate discontinuation is warranted when:

• Patient presents with acute neurological symptoms including vision changes 1
• Stroke workup is underway and visual symptoms need clear assessment without confounding medication effects 1
• Patient has diabetic retinopathy and presents with acute vision loss (risk of vitreous hemorrhage) 1

Risk Stratification Factors

High-risk features requiring latanoprost discontinuation:

• Active stroke symptoms with visual complaints 1
• Recent retinal vascular events 1
• Diabetic retinopathy with hemorrhagic complications 1
• Unexplained vision reduction requiring investigation 2

Mechanism of Concern

Prostaglandin-Mediated Vascular Effects

• Latanoprost is a prostaglandin F2α analogue that works by increasing uveoscleral outflow 3, 4
• Prostaglandins have systemic vascular effects beyond their ocular mechanism 5
• While systemic cardiovascular effects are rare, they include chest pain/angina pectoris occurring at 1-2% incidence 1

Inflammatory Complications

• Intraocular inflammation (iritis/uveitis) is documented as an adverse effect 1
• Herpes keratitis reactivation has been reported in post-marketing surveillance 1, 5
• These inflammatory processes could theoretically complicate acute stroke assessment 1

Critical Pitfalls to Avoid

• Do not assume all vision changes in stroke patients are neurological—latanoprost can independently cause retinal artery embolus and macular edema that require ophthalmologic evaluation 1
• Do not restart latanoprost without ophthalmologic clearance if vision changes occurred during stroke presentation 1, 2
• Do not overlook diabetic retinopathy status—these patients face higher risk of vitreous hemorrhage with latanoprost use 1

Post-Stroke Management Considerations

Resumption Criteria

• Ophthalmologic examination should confirm no retinal vascular complications before restarting 1, 2
• Stroke workup should be complete with clear attribution of visual symptoms 1
• Alternative glaucoma medications may be considered if retinal vascular risk remains elevated 3

Monitoring Requirements

• Any patient complaining of vision reduction while using latanoprost requires full ophthalmologic investigation 2
• Patients with pre-existing diabetic retinopathy need heightened surveillance for hemorrhagic complications 1