Qualities of purifying medicine

Purifying medicine is very sharp, hot, mobile (sara) and vikasi (the verse also seems to name subtlety), and by these it cleanses upward or downward. The emetic carries the unripe doshas upward, while the purgative, being digested, carries the ripe doshas downward; the commentary adds that the purgative works by its qualities and the emetic by its specific potency (prabhava).