The invention relates to an improvement in a method of rapidly inducing thrombolysis in a mammal comprising intramuscularly administering a composition comprising (1) a protein-thrombolytic agent and (2) an enhancer in an amount sufficient to increase the rate of absorption of the thrombolytic agent into the bloodstream of the mammal. The improvement comprises intramuscularly administering with the enhancer a protein thrombolytic agent having a rate of disappearance from the blood lower than that of wild-type t-PA in an amount sufficient to produce a thrombolytically effective level of the thrombolytic agent in the bloodstream of the mammal for a period of time sufficient to induce and complete thrombolysis, wherein the amount is such that significant bleeding resulting from the presence of and persistence of the thrombolytic agent in the bloodstream is avoided.
