A 34-year-old woman comes to the clinic with a facial rash, joint pains, and oral ulcers. She has no associated fever or other systemic symptoms and otherwise feels well. Medical history is unremarkable, and the patient's only concurrent medication is an oral contraceptive. She does not smoke and consumes alcohol only on social occasions. Antinuclear and anti-double-stranded DNA antibody titers are elevated. Creatinine and complement levels are normal. The patient is diagnosed with systemic lupus erythematosus, and therapy with hydroxychloroquine is initiated. Which of the following evaluations should be done periodically while the patient is taking this medication?

A. Audiometry
B. Echocardiogram
C. Eye examination
D. Liver function panel
E. Pulmonary function tests
F. Thyroid-stimulating hormone

Correct Answer: C. Eye Examination.

Hydroxychloroquine (Antimalarial drug)

↓

Inhibits lysosomal activity

↓

Antigen presentation ↓

↓

Immune Complex Formation ↓
↓

Accumulation of Drugs in Retinal Tissues [Retinal pigment epithelium (RPE)]

↓

Retinal Toxicity
↓
Disruption of RPE Function

(RPE supports photoreceptors and maintains the blood-retinal barrier)
↓
Photoreceptor Damage

↓

Damage to cones and rods

↓
Visual Disturbances

Blurred vision, color vision changes, and possible vision loss
↓
Periodic Eye Examinations Recommended

Regular screening for retinal changes during hydroxychloroquine treatment

Early detection of toxicity to prevent permanent damage

Why Other Options are Wrong:

1. Audiometry

   • Reason: Hydroxychloroquine is not known to cause ototoxicity or hearing loss. Audiometric evaluation is unnecessary for patients taking this medication, as it does not impact hearing function.

2. Echocardiogram

   • Reason: While SLE can affect the heart (e.g., pericarditis, Libman-Sacks endocarditis), hydroxychloroquine does not have direct cardiac toxicity. Routine echocardiograms are not required solely due to hydroxychloroquine use.

3. Liver Function Panel

   • Reason: Hydroxychloroquine is not primarily associated with liver toxicity. Although some medications used in SLE may affect liver function, routine liver panels are not specifically warranted for hydroxychloroquine.

4. Pulmonary Function Tests

   • Reason: Hydroxychloroquine is not linked to pulmonary toxicity. While SLE can cause pulmonary complications, such as pleuritis or interstitial lung disease, these would not be monitored specifically due to hydroxychloroquine use.

5. Thyroid-stimulating hormone (TSH)

   • Reason: Hydroxychloroquine does not have a direct effect on thyroid function. While SLE can be associated with autoimmune thyroid disease, TSH monitoring is not specifically indicated for patients taking hydroxychloroquine.

FLASHCARDS

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