Clinicians should monitor for potential drug-drug interactions (DDIs) when managing patients with rheumatoid arthritis (RA) who are being treated with Janus kinase (JAK) inhibitors, according to a recent study published in Rheumatology and Therapy.

Given the changing treatment landscape for RA, the study authors aimed to summarize information surrounding potential DDIs with JAK inhibitors in order to help providers and patients make informed decisions. “The objective of this retrospective, cross-sectional study was to describe the frequency of prescription claims for drugs that may interact and require adjustment in therapy with JAK inhibitors, without documentation of concomitant administration, among adult patients with RA in a large, administrative US claims database,” the study authors explained.

The authors utilized the IBM MarketScan Research Commercial and the Medicare Supplemental Database to obtain data on patients 18 years of age and older diagnosed with RA between January 1, 2013, and March 31, 2017 (the index period) who had at least 2 outpatient claims at least 30 days apart or at least 1 inpatient visit claim.


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“During the study period, from January 1, 2013 to March 31, 2018, strong organic anion transporter (OAT3) inhibitors, strong cytochrome P450 (CYP) 3A4 inhibitors, and moderate or strong CYP3A4 inhibitors in combination with strong CYP2C19 inhibitors, were identified as drugs with potential for drug–drug interactions with JAK inhibitors approved for RA treatment in the US,” the authors explained.

Of the total 152,853 patients who met eligibility criteria (76% female; median age, 57 years), up to 10% were found to have been prescribed a medication with a potential interaction with a JAK inhibitor. The authors reported that <0.1% of patients had a claim for a strong OAT3 inhibitor, 1% had a claim for the combination of a strong CYP3A4 plus a strong CYP2C19 inhibitor, 3% had a claim for a strong CYP3A4 inhibitor, and nearly 10% had claims for a moderate CYP3A4 as well as a strong CYP2C19 inhibitor.

  • The most commonly prescribed drugs reported in the study by metabolic pathway included:
  • Strong OAT3 inhibitors: probenecid, colchicine-probenecid
  • trong CYP3A4 inhibitors: clarithromycin, clotrimazole troche, clarithromycin ER, loperamide hydrochloride, suboxone
  • Moderate CYP3A4 inhibitors: fluconazole, sertraline hydrochloride, venlafaxine hydrochloride ER, paroxetine hydrochloride, lovastatin
  • Strong CYP2C19 inhibitors: fluconazole, amitriptyline hydrochloride, fluoxetine hydrochloride, lansoprazole, gemfibrozil.

The study authors noted that adverse clinical outcomes related to the potential co-administration of JAK inhibitors with these agents were not evaluated in the study. They added, “Many of the potentially interacting drugs observed in this real-word analysis may be used acutely (eg, antifungals), which may require a temporary treatment interruption or dose adjustment of the chronic RA therapy.”

Disclosure: Multiple authors declared conflicts of interest. Please refer to the original article for a full list of disclosures.

Reference

Walton A, Paik J, Quebe A, et al.  Frequency of prescription claims for drugs that may interact with Janus kinase inhibitors among patients with rheumatoid arthritis in the US. Rheumatol Ther. 2021 doi.org/10.1007/s40744-020-00275-8.

This article originally appeared on MPR