Comparison of Liver Injury in Patients Taking Methotrexate and Leflunamide in Rheumatoid Arthritis

Background: Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects the joints, leading to inflammation and potential joint damage. Methotrexate (MTX) and Leflunomide (LEF) are commonly used disease-modifying antirheumatic drugs (DMARDs) for RA, but their hepatotoxic effects require careful monitoring. Objective: This study aimed to compare the incidence of liver injury in RA patients treated with Methotrexate versus Leflunomide. Methods: This prospective study was conducted from January 2023 to June 2023 and included 80 RA patients aged 20 years or older, who reported to the Medicine Department at Combined Military Hospital (CMH) Lahore. Patients were divided into two groups: Group A received 20 mg/day Methotrexate (n=40), and Group B received 20 mg/day Leflunomide (n=40). Exclusion criteria included pregnant females, patients with hepatitis B or C, those with known allergies to Methotrexate or Leflunomide, and alcoholics. Baseline investigations, including liver enzyme levels (ALT/AST), were performed, and patients were monitored every three months. Hepatotoxicity was defined as an increase in ALT/AST levels to at least twice the upper limit of normal (ULN). Data were analyzed using SPSS version 25.0, with mean and standard deviation for quantitative data and frequency and percentage for qualitative data. The Chi-square test was used to compare variables, with p<0.05 considered statistically significant. Results: Out of 80 patients, 43 (53.75%) were female, and 37 (46.25%) were male. In Group A, 7 patients (17.5%) had elevated ALT/AST levels, while 6 patients (15%) in Group B exhibited elevated liver enzymes. The mean age was 52.4 ± 8.3 years in Group A and 50.6 ± 9.1 years in Group B. The mean BMI was 26.7 ± 3.5 kg/m² in Group A and 27.1 ± 3.8 kg/m² in Group B. No statistically significant difference in hepatotoxicity was observed between the two groups (p>0.05). Conclusion: Methotrexate and Leflunomide were equally effective in treating RA, with no significant difference in liver toxicity observed between the two groups. Both medications have comparable risks for hepatotoxicity, necessitating regular liver function monitoring during treatment.