Adverse effects of low dose methotrexate in rheumatoid arthritis patients. A hospital-based study

Area of Science:

• Rheumatology
• Pharmacology
• Clinical Medicine

Background:

• Methotrexate (MTX) is a cornerstone therapy for rheumatoid arthritis (RA).
• Understanding MTX side effects and associated risk factors is crucial for patient management.
• Identifying predisposing variables can optimize treatment strategies and minimize adverse events.

Purpose of the Study:

• To evaluate the spectrum and frequency of side effects associated with methotrexate treatment in rheumatoid arthritis patients.
• To identify potential clinical and demographic variables that predispose patients to methotrexate-induced adverse events.

Main Methods:

• Retrospective analysis of 116 rheumatoid arthritis patients treated with methotrexate over a 3-year period (2006-2008).
• Data collection included MTX side effects, patient demographics, and clinical characteristics.
• Statistical analysis, including logistic regression, was performed to identify predictive variables for MTX side effects.

Main Results:

• Gastrointestinal disturbances (31%) were the most common MTX side effect, followed by central nervous system symptoms (18%) and hepatotoxicity (14%).
• Methotrexate-induced lung injury and rheumatoid nodule enlargement were the least common (1%).
• Renal impairment (OR=7.14, p<0.05) was the most significant predictor of MTX side effects, along with male gender, non-Saudi nationality, smoking, steroid use, hypoalbuminemia, and extra-articular manifestations.

Conclusions:

• Methotrexate is a widely used and effective drug for rheumatoid arthritis, but careful monitoring for side effects is essential.
• Gastrointestinal disturbances are the most frequent adverse events, whereas pulmonary complications are rare.
• While several factors are associated with MTX side effects, renal impairment is a key risk factor requiring close attention in disease management.