Use of antimalarials in dermatology

Area of Science:

• Dermatology
• Rheumatology
• Pharmacology

Background:

• Chloroquine and hydroxychloroquine have been utilized for over 60 years to treat inflammatory conditions.
• Their complex mechanisms of action continue to reveal new therapeutic indications.
• Fear of side effects, particularly irreversible retinopathy, often restricts their clinical application.

Purpose of the Study:

• To highlight the importance of correct dosing for safe and effective antimalarial therapy.
• To review the established and emerging indications for chloroquine and hydroxychloroquine in inflammatory diseases.
• To emphasize the safety profile when maximal daily dosages are observed.

Main Methods:

• Dosage calculations based on ideal body weight (3.5-4 mg/kg for chloroquine, 6-6.5 mg/kg for hydroxychloroquine).
• Consideration of actual body weight if lower than ideal body weight.
• Review of therapeutic applications in various dermatological and rheumatological conditions.

Main Results:

• Adherence to maximal daily dosages significantly reduces the risk of side effects, including retinopathy.
• Safe and effective treatment is achievable for conditions such as lupus erythematosus, REM syndrome, porphyria cutanea tarda, cutaneous sarcoidosis, and dermatomyositis.
• Antimalarials can be effective in refractory cases of Sjögren syndrome, granuloma annulare, and erosive lichen planus, sometimes in combination with quinacrine.

Conclusions:

• Chloroquine and hydroxychloroquine are essential, well-tolerated drugs in dermatology.
• Correct dosing is paramount for ensuring safety and efficacy.
• These antimalarials are valuable as part of combination therapy, e.g., with corticosteroids, due to synergistic effects and reduced adverse events.