Correct spelling for the English word "svapnia" is [svˈapniə], [svˈapniə], [s_v_ˈa_p_n_i__ə] (IPA phonetic alphabet).
Trade name of a preparation of opium, used in doses of gr. 1/2-1 (0.03-0.06).
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.