What monitoring is recommended for patients on hydroxychloroquine (HCQ)?

Hydroxychloroquine Monitoring Recommendations

Patients on hydroxychloroquine (HCQ) should receive baseline ocular examination within the first year of starting therapy, followed by annual screening beginning after 5 years of use for patients without major risk factors, and earlier for those with risk factors. 1

Ophthalmologic Monitoring

Baseline Screening

• A baseline fundus examination should be performed within the first year of starting HCQ to rule out preexisting maculopathy 1
• For patients with pre-existing macular conditions, baseline screening should include automated visual fields and spectral-domain optical coherence tomography (SD-OCT) 1, 2

Regular Screening Schedule

• For patients on acceptable doses without major risk factors, annual screening can be deferred until after 5 years of HCQ use 1
• After 5 years, annual screening should include:
  • Automated visual fields (10-2 pattern for non-Asian patients; 24-2 or 30-2 for Asian patients) 1
  • Spectral-domain optical coherence tomography (SD-OCT) 1
• For patients at higher risk of retinal damage, annual screening should begin sooner and include best corrected distance visual acuity (BCVA), visual fields, and SD-OCT 3

Additional Testing When Available

• Multifocal electroretinogram (mfERG) can provide objective corroboration for visual fields 1
• Fundus autofluorescence (FAF) can show damage topographically 1, 2

Laboratory Monitoring

• Annual complete blood count (CBC) and liver function tests (LFTs) are conditionally recommended 1
• Package insert indicates periodic laboratory monitoring should be performed for patients on prolonged therapy 1

Risk Factors for Retinal Toxicity

• High daily dose (>5.0 mg/kg of actual body weight) 1, 3
• Long duration of use (>5 years) 1
• Renal disease or impaired renal function 1, 3
• Concomitant use of tamoxifen 1, 3
• Concurrent macular disease 1, 3
• Asian descent (may show extramacular pattern of damage) 1

Dosing Considerations

• Maximum recommended daily dose is 5.0 mg/kg of actual body weight 1
• At recommended doses, risk of toxicity is:
  • Under 1% in the first 5 years of therapy 1
  • Under 2% up to 10 years 1
  • Increases to almost 20% after 20 years 1

Important Clinical Considerations

• Retinopathy is not reversible, and there is no present therapy 1, 4
• Early detection (before RPE damage) is crucial to prevent central visual loss 1, 2
• Retinal toxicity can progress even after discontinuation of HCQ 1, 4
• Visual acuity usually remains excellent until severe stages of damage 1
• Questionable test results should be repeated or validated with additional procedures to avoid unnecessary cessation of valuable medication 1

Special Populations

• In pediatric patients, yearly screening is recommended rather than waiting 5 years between baseline and subsequent annual screening 1
• In Asian patients, visual field testing should be performed in the central 24 degrees instead of the central 10 degrees 3

Communication

• Patients and prescribing physicians should be informed about the risk of toxicity, proper dose levels, and the importance of regular screening 1
• Screening can be viewed as a means of helping patients continue HCQ safely as much as preventing retinal damage 1