A method of subcutaneous delivery of a drug or a therapeutic agent to a subject to treat a localized condition, the method including obtaining a liquid composition including the drug or the therapeutic agent dissolved in a tumescent solution, wherein the tumescent solution includes the drug or the therapeutic agent a vasoconstrictor; and a pharmaceutically acceptable carrier; and delivering a mass of the liquid composition subcutaneously to a localized tissue in the subject, wherein the drug or the therapeutic agent treats the localized condition in the localized tissue, wherein a concentration of the drug or the therapeutic agent subcutaneously delivered exceeds a concentration of the drug or the therapeutic agent that can be safely achieved by intravenous delivery, and wherein an amount of the drug or the therapeutic agent located at an outer boundary of the mass of fluid and available for absorption is less than an amount of the drug or the therapeutic agent located within a central portion of the mass of fluid and virtually isolated from the systemic circulation by virtue of capillary vasoconstriction.