A device, comprising: - a housing having a first end, a second end, a first cylinder positioned within the housing, a second cylinder positioned within the housing and parallel to the first cylinder, and a channel connecting the first cylinder to the second cylinder proximate to the second end; - a piston slidably positioned within the first cylinder; - a deployment spring configured to force the piston toward the second end of the housing; - an activation trigger positioned proximate to the first end of the housing, wherein the activation trigger is configured to retain the piston proximate the first end of the housing prior to actuation of the activation trigger, and wherein the activation trigger is configured to release the piston and to allow the piston to move along the first cylinder upon actuation of the activation trigger; - a penetrable septum positioned at the first end of the housing proximate to the activation trigger, wherein the penetrable septum separates an interior of the housing from an external environment surrounding the housing; - a cartridge having a first end and a second end, wherein the cartridge contains at least one therapeutic agent, wherein the cartridge is positioned within the second cylinder such that the first end of the cartridge faces the first end of the housing and the second end of the cartridge faces the second end of the housing, and wherein the cartridge has a plunger at the second end thereof; - a needle hub positioned adjacent to the first end of the cartridge and within the second cylinder, wherein the cartridge is slidably positioned within the needle hub; - a dual-ended needle positioned within the needle hub; and - a fluid positioned within the first cylinder, the channel, and the second cylinder, wherein the piston is configured such that, when the activation trigger is actuated, the activation trigger releases the piston and the deployment spring causes the piston to travel along the first cylinder toward the second end of the housing, thereby driving at least some of the fluid through the channel into the second cylinder, thereby driving the cartridge, the needle hub, and the needle toward the first end of the housing, and thereby causing the needle to penetrate the septum and subsequently to penetrate the cartridge; and wherein the plunger is configured such that continued travel of the fluid causes the plunger to move within the cartridge and force at least some of the at least one therapeutic agent to extrude through the needle. - a housing having a first end, a second end, a first cylinder positioned within the housing, a second cylinder positioned within the housing and parallel to the first cylinder, and a channel connecting the first cylinder to the second cylinder proximate to the second end; - a piston slidably positioned within the first cylinder; - a deployment spring configured to force the piston toward the second end of the housing; - an activation trigger positioned proximate to the first end of the housing, wherein the activation trigger is configured to retain the piston proximate the first end of the housing prior to actuation of the activation trigger, and wherein the activation trigger is configured to release the piston and to allow the piston to move along the first cylinder upon actuation of the activation trigger; - a penetrable septum positioned at the first end of the housing proximate to the activation trigger, wherein the penetrable septum separates an interior of the housing from an external environment surrounding the housing; - a cartridge having a first end and a second end, wherein the cartridge contains at least one therapeutic agent, wherein the cartridge is positioned within the second cylinder such that the first end of the cartridge faces the first end of the housing and the second end of the cartridge faces the second end of the housing, and wherein the cartridge has a plunger at the second end thereof; - a needle hub positioned adjacent to the first end of the cartridge and within the second cylinder, wherein the cartridge is slidably positioned within the needle hub; - a dual-ended needle positioned within the needle hub; and - a fluid positioned within the first cylinder, the channel, and the second cylinder, wherein the piston is configured such that, when the activation trigger is actuated, the activation trigger releases the piston and the deployment spring causes the piston to travel along the first cylinder toward the second end of the housing, thereby driving at least some of the fluid through the channel into the second cylinder, thereby driving the cartridge, the needle hub, and the needle toward the first end of the housing, and thereby causing the needle to penetrate the septum and subsequently to penetrate the cartridge; and wherein the plunger is configured such that continued travel of the fluid causes the plunger to move within the cartridge and force at least some of the at least one therapeutic agent to extrude through the needle.