IgG1-monoclonal antibody directed against tumor necrosis factor used for treatment of auto-immune diseases like Rheumatoid Arthritis. Minimal or low excretion into breast milk due to high molecular weight. In breastfed babies whose mothers were on this medication plasma levels were undetectable and failed to show side effects. It should be avoid in the first two post-partum weeks since pass of significant amounts of IgG to the milk can occur in the first 3 - 4 post-partum days.