Impact of Interferons and Biological Drug Inhibitors of IL-2 and IL-6 on Small-Molecule Drug Metabolism Through the Cytochrome P450 System

Abstract

Objective: Assess the impact of interferons and interleukin (IL)-2 and IL-6 inhibitors on cytochrome P450 (CYP) drug metabolism in human subjects. Data Sources: PubMed search from 1980 to March 31, 2021, limited to human subjects and English language via search strategy: (biological drug names) [AND] (cytochrome [OR] CYP metabolism). Study Selection and Data Extraction: Narrative review of human studies assessing biological drugs in select classes that affect CYP drug metabolism. Data Synthesis: Exogenous interferons suppress CYP1A2 (theophylline, caffeine, antipyrone) clearance by 20% to 49% in patients; have minimal impact on CYP3A4 (midazolam and dapsone), CYP2C9 (tolbutamide), or CYP2C19 (mephenytoin) metabolism; and increase CYP2D6 (debrisoquine, dextromethorphan) metabolism. Biological IL-2 inhibitors (basiliximab, daclizumab) have no effect on metabolism via CYP1A2 (caffeine), CYP2C9 (s-warfarin), CYP2C19 (omeprazole), CYP2D6 (dextromethorphan), and CYP3A4 (midazolam, tacrolimus) but may enhance CYP3A4 (cyclosporin) metabolism over time. IL-6 inhibitors (sirukumab, tocilizumab, sarilumab) significantly enhance metabolism via CYP2C9 (s-warfarin), CYP2C19 (omeprazole), and CYP3A4 (simvastatin, midazolam) and reduce metabolism via CYP1A2 (caffeine). Relevance to Patient Care and Clinical Practice: Patients using interferons, IL-2, or IL-6 blocking drugs at steady state with CYP substrates could have altered drug metabolism and experience adverse events. With interferons and biological anti-inflammatory drugs, some isoenzymes will be inhibited, whereas others will be enhanced, and the magnitude of the effect can sometimes be significant. In clinical practice, clinicians may consider these metabolic changes as an additive effect to a patient’s entire disease and medication profile when determining risk/benefit of treatment. Conclusions: Interferon therapy or inflammatory suppression via IL-2 or IL-6 can alter steady-state concentrations of CYP-metabolized small-molecule drugs.