Moderate weekly alcohol consumption in rheumatoid arthritis (RA) patients who take methotrexate (MTX) therapy may not be as dangerous as previously suggested, according to new research.
The study, “Quantifying the hepatotoxic risk of alcohol consumption in patients with rheumatoid arthritis taking methotrexate,” was recently published in the journal Annals of the Rheumatic Diseases.
Methotrexate is a first-line immunosuppressant often prescribed to patients with RA. The medication is generally well tolerated, however it is known to have the potential to cause liver damage (hepatotoxicity).
Given the well-known adverse effects of alcohol on the liver, RA patients on MTX have traditionally been advised to limit or even avoid alcohol while taking the medication. The official guidelines set forth by the American College of Rheumatology (ACR) recommend abstaining from alcohol with only occasional exceptions, according to the authors.
While the risk of hepatotoxicity in patients taking methotrexate has been researched at length, there is little evidence regarding the combined effects of MTX and alcohol on liver toxicity.
To further quantify the risk of hepatotoxicity in RA patients taking MTX who also consume alcohol, the researchers reviewed data on 11,839 patients with RA who had started methotrexate treatment between 1987 and 2016.
The researchers defined hepatotoxicity as an elevation in the liver enzymes alanine transaminase and aspartate aminotransferase. An elevation in liver enzymes greater than three times the upper normal limit is referred to as transaminitis, a concept frequently utilized in the clinical setting as a surrogate for liver injury.
Rates of transaminitis were compared to weekly alcohol consumption in RA patients taking MTX.
In this study, a unit of alcohol represents 10 mL or eight grams of pure alcohol.
The researchers found that, overall, increased weekly alcohol consumption was associated with an increased risk of transaminitis. Consuming 15 to 21 alcoholic unit drinks was associated with a possible risk of hepatotoxicity, while consuming more than 21 unit drinks per week significantly increased the risk of transaminitis.
Interestingly, consuming fewer than drinks a week did not appear to be associated with an increased risk of transaminitis.
Despite the findings, the authors caution that monitoring for transaminitis may not fully capture all liver damage occurring in patients taking methotrexate who are also consuming alcohol. They note that patients can sometimes develop severe liver damage without an associated transaminitis.
“In conclusion, in the largest study of its kind to date, we have shown no increase in the risk of transaminitis in patients who consume [less than] 14 units alcohol per week while taking MTX,” researchers wrote. “This may provide the practical and useful information that drinking alcohol within nationally recommended levels in the U.K. is safe, in terms of risk of transaminitis, for patients commencing MTX therapy for RA.”