What are the management options for Plaquenil (hydroxychloroquine)-induced pigment reduction?

Management of Hydroxychloroquine-Induced Retinal Pigment Reduction

The primary management for hydroxychloroquine-induced retinal pigment reduction is immediate discontinuation of the medication, as there is no effective treatment to reverse established retinal toxicity. 1

Understanding Hydroxychloroquine Retinopathy

Hydroxychloroquine (Plaquenil) retinopathy is a serious complication characterized by damage to photoreceptors that can progress to retinal pigment epithelium (RPE) disruption. This toxicity:

• Initially affects photoreceptors before causing RPE damage 1
• Can continue to progress even after drug discontinuation 1
• Is not treatable once established, making early detection crucial 1
• Presents different patterns based on ethnicity:
  • Parafoveal distribution in European descent patients
  • More peripheral extramacular distribution near the arcades in Asian patients 1

Risk Factors for Retinal Toxicity

Several factors increase the risk of developing hydroxychloroquine retinopathy:

• Daily dose exceeding 5 mg/kg real body weight (most significant risk factor) 1
• Duration of treatment (especially >5 years) 2
• Cumulative dose >1000g 3
• Pre-existing retinal or macular disease 1
• Chronic kidney disease 1
• Concomitant tamoxifen use 2

Clinical Presentation

Patients with hydroxychloroquine retinopathy may present with:

• Central or paracentral scotomas 4
• Normal visual acuity in early stages (most patients are asymptomatic) 1
• Reading difficulties or metamorphopsia in perceptive patients 1
• "Bull's eye" maculopathy in advanced cases (should no longer be seen with proper screening) 1
• Progressive visual loss if the drug is not discontinued 4

Management Algorithm

1. Immediate discontinuation of hydroxychloroquine

   • This is the only effective intervention for established toxicity 1, 4
   • Decision should be made in conjunction with the prescribing physician 5

2. Ophthalmologic follow-up

   • Continue monitoring as toxicity may progress even after drug discontinuation 1
   • Document extent of damage to establish baseline for future comparison

3. Consider alternative medications

   • For patients with autoimmune conditions requiring antimalarial therapy:
     • Consider alternative immunosuppressants in consultation with rheumatologist
     • For lupus patients, options include azathioprine, methotrexate, or mycophenolate mofetil 1

4. Supportive care for visual impairment

   • Low vision aids for patients with significant visual loss
   • Visual rehabilitation services if needed

Prevention Strategies

To prevent hydroxychloroquine retinopathy:

1. Proper dosing

   • Keep daily dose ≤5 mg/kg real body weight 1
   • Calculate dose based on real weight rather than ideal weight 1

2. Regular screening

   • Baseline examination before starting treatment 1
   • Annual screening after 5 years of use (or sooner with risk factors) 3
   • Screening should include:
     • 10-2 automated visual fields
     • At least one objective test: spectral domain optical coherence tomography (SD-OCT), multifocal electroretinogram (mfERG), or fundus autofluorescence (FAF) 3

3. Patient education

   • Inform patients about risk of toxicity and importance of screening 3
   • Advise about possible symptoms to report (reading difficulties, missing central vision)

Important Caveats

• No treatment exists to reverse established hydroxychloroquine retinopathy 3
• Toxicity may continue to progress even after drug discontinuation 1
• Visual acuity may remain good until advanced stages, making screening crucial 1
• The goal of screening is to detect early changes to minimize (not necessarily prevent) visual loss 3
• Amsler grid testing is no longer recommended for screening 3

By following these guidelines, clinicians can minimize the risk of permanent vision loss from hydroxychloroquine retinopathy through early detection and prompt discontinuation of the medication when toxicity is identified.