Date of Award


Degree Type

Selective Evidence-Based Medicine Review

Degree Name

Master of Science in Health Sciences - Physician Assistant


Physician Assistant Studies

Department Chair

John Cavenagh, MBA, PhD, PA-C


OBJECTIVE: The objective of this selective EBM review is to determine whether or not Methotrexate (MTX) is an effective treatment in partially or totally reducing the symptoms of Myasthenia Gravis (MG) patients.

STUDY DESIGN: Review of three English language studies; one Case Series Study following 3 patients with concomitant MG and Rheumatoid Arthritis treated with MTX published in 2014, one Single-Blind Randomized Control Trial (RCT) comparing MTX and AZA (Azathioprine) published in 2011, and one Double-blind, placebo-controlled Randomized Control Trial published in 2016.

DATA SOURCES: Three primary research studies published in peer reviewed journals; found on the PubMed database. Each study’s results included patient oriented outcomes that were relevant to this selective EBM review.

OUTCOMES MEASURED: Each study assessed the MG outcomes and quality of life measures after treatment with Methotrexate. The two RCTs used the following assessment tools to quantify their outcomes: Quantitative MG (QMG) Score, Manual Muscle Testing (MMT), MG Quality of Life (MGQOL), MG-Activities of Daily Living (MG-ADL), Minimum Manifestations Status (MMS), and MG Composite Change.

RESULTS: The Case Series Study showed an association between MTX and improved MG symptoms; however it did not show cause and effect. The Single-Blind RCT compared MTX and AZA (enrollment: AZA n = 15; MTX n = 16). Similarities between both groups were found in regards to MMS after 24 months (AZA n = 7; MTX n = 9; p = 0.83; ABI = .03; NNT = 34), and safety; giving promise to MTX’s efficacy. The Double-blind, placebo-controlled RCT (enrollment: MTX n = 25; Placebo n = 25) found MTX did not improve QMG, MMT, MGQOL, MG-ADL, or MG Composite Change over 12 months. Withdrawals: Placebo n = 7; MTX n = 1; no serious MTX-related adverse events were encountered. Both RCT’s data was determined to be not statistically significant due to small enrollment size. P-values were >0.05 and 95% CI were too wide to be precise.

CONCLUSION: Based on the Case Series Study and two RCTs, MTX is not an effective treatment in partially or totally reducing the symptoms of MG patients.