An intravenous (IV) spike for administering a medicinal fluid from a container includes an elongate body having an upper portion and a lower portion, and a plurality of screw threads disposed along and protruding radially outward from an outer surface of the lower portion of the elongate body. The elongate body is configured to be coupled to a drip chamber. The outer surface is configured to engage an internal surface of an outlet port of the container in a coupled configuration. In the coupled configuration edges of the screw threads grip and engage the internal surface of the outlet port of the container to create a seal between the lower portion of the elongate body and the outlet port of the container and to retain the body in the outlet port.