Can Plaquenil Cause Lung Disease?
While hydroxychloroquine (Plaquenil) does not typically cause direct pulmonary toxicity as a primary adverse effect, the available evidence does not identify lung disease as a recognized complication of this medication. The American College of Chest Physicians guidelines extensively detail hydroxychloroquine's toxicity profile without listing pulmonary toxicity as a concern, focusing instead on cardiac, ocular, neuromuscular, and gastrointestinal adverse effects 1.
Primary Toxicities to Monitor
The well-established adverse effects of hydroxychloroquine include:
Ocular toxicity: Irreversible retinopathy is the most serious concern, though risk remains <1% in the first 5 years and <2% up to 10 years when dosed at ≤5.0 mg/kg real body weight 2. Ophthalmologic screening every 6-12 months is recommended 1, 2.
Cardiac toxicity: Cardiomyopathy, heart block, and QRS/T-wave abnormalities can occur with prolonged therapy 1. Hydroxychloroquine causes less cardiac disturbance than chloroquine 1.
Neuromuscular toxicity: Toxic myopathy and peripheral neuropathy may develop with prolonged use, but these improve if the drug is promptly withdrawn 1.
Gastrointestinal effects: GI upset, headache, and visual disturbances are common with oral therapy 1.
Use in Lung Disease Patients
Importantly, hydroxychloroquine has been used to treat certain lung diseases rather than cause them:
The medication has been employed in sarcoidosis and pulmonary fibrosis as an anti-inflammatory agent 1.
Multiple studies have investigated hydroxychloroquine for childhood interstitial lung diseases (chILD), with a generally favorable safety profile 3, 4, 5, 6.
A randomized controlled trial in chILD found hydroxychloroquine was well tolerated with adverse events not different from placebo 5.
Clinical Caveat
The one respiratory manifestation mentioned in guidelines relates to sirolimus (not hydroxychloroquine), where evaluation for drug-induced pulmonary toxicity is recommended if new respiratory symptoms develop 1. This distinction is critical—hydroxychloroquine does not carry this same pulmonary toxicity warning.
Monitoring Recommendations
For patients on hydroxychloroquine therapy 1, 2:
- Ophthalmologic examination every 6-12 months
- Consider yearly ECG, particularly in asymptomatic patients
- Monitor for drug interactions with D-penicillamine and cimetidine
- Dose should not exceed 250 mg/day to minimize irreversible retinopathy and ototoxicity risk
The evidence consistently demonstrates that hydroxychloroquine is generally safe with a well-characterized toxicity profile that does not include pulmonary disease as a recognized adverse effect 2, 4.