Pharmacokinetics of tazarotene and acitretin in psoriasis.

INTRODUCTION: Psoriasis is a prevalent cutaneous condition with severe physical and psychological manifestations. Since the advent of biologics, clinical outcomes in psoriasis have improved. However, retinoids are useful in the correct clinical context. Tazarotene and acitretin are currently the only US Food and Drug Administration approved retinoids for treatment of psoriasis. Both topical tazarotene and oral acitretin act on retinoic acid receptors and retinoid-X-receptors, resulting in altered gene expression of inflammatory cytokines and inhibition of keratinocyte proliferation. Areas covered: This article provides an in-depth pharmacologic and clinical review on the use of tazarotene and acitretin in psoriasis. The PubMed database was searched using combinations of keywords: acitretin, bioavailability, dosing, efficacy, etretinate, interactions, mechanism, pharmacodynamics, pharmacokinetics, pharmacogenetics, psoriasis, safety, tazarotene, tolerability, and toxicity. Expert opinion: Tazarotene and acitretin are effective treatments for psoriasis. Benefits include lack of immunosuppression and success treating inflammatory psoriasis. When combined with other topical and systemic agents, both retinoids improve clinical efficacy while lowering the treatment threshold. However, topical adherence and bothersome side effects can limit retinoid use. Acitretin and tazarotene both improve outcomes through a unique mechanism that especially benefits subsets of patients, despite side effects and limitations.