1909, from empathy on model of sympathetic and said to have been originally meant to be distinct from empathic. A 1918 article in The Journal of Abnormal Psychology (vol. XIII) emphatically recommended empathic:

Sympathetic, the adjective, seems to have built up—so philologists say—on the analogy of pathetic: that is, sympathetic ought to be sympathic as indeed in some languages it becomes. And a little of the pathos of pathetic has usually clung to sympathetic. As for empathy, however, the adjective empathic seems to be more suitable than empathetic, if only because the latter would even more damagingly suggest pathos. [E.E. Southard]

Related: Empathetically.

1909 [Titchener], from empathy + -ic. Related: Empathically. Treated as a coinage of Titchener's when it appeared in psychological writing; there are dozens of uses of empathic in printed material from the late 19th century but most of these appear to be errors for emphatic.

"understand and share the feelings of another," by 1917, from empathy + -ize. Related: Empathized; empathizing. Earlier appearances of the word in print seem to be an error for emphasize:

Obstetric Therapeutics.—Prof. Smiley will devote attention to this very important branch of the practice of medicine; he will especially empathize the Homoepathic therapeutics so often called for during the period of gestation. [The Medical Advance, Chicago, March 1895]

word-forming element meaning "near, at, in, on, within," from Greek en "in," cognate with Latin in (from PIE root *en "in"), and thus with en- (1). Typically assimilated to em- before -p-, -b-, -m-, -l-, and -r-.

Proto-Indo-European root meaning "to suffer."

It forms all or part of: anthropopathy; antipathy; apathy; empathy; idiopathy; nepenthe; osteopathy; -path; pathetic; -pathic; patho-; pathogenic; pathognomonic; pathology; pathos; -pathy; psychopathic; sympathy.

It is the hypothetical source of/evidence for its existence is provided by: Greek pathos "suffering, feeling, emotion, calamity," penthos "grief, sorrow;" Old Irish cessaim "I suffer;" Lithuanian kenčiu, kentėti "to suffer," pakanta "patience."