An apparatus, comprising: a housing defining an inner volume configured to receive a safety tab; a cartridge assembly, at least a portion of the cartridge assembly configured to be movably disposed in the housing, the cartridge assembly including a first movable member and a second movable member, the first movable member defining an inner volume, at least a portion of the second movable member being movably disposed in the innervolume of the first movable member between a first position and a second position relative to the first movable member, wherein the safety tab is a substantially elongate member disposable within a slot in the proximal end portion of the housing, whereby the safety tab can traverse the inner volume of the housing such that when the cartridge assembly is inserted into the inner volume of the housing, the safety tab engages an outer surface of the cartridge assembly and engage the first movable member to limit at least a distal movement of the first movable member relative to the housing; a first reservoir disposed within the inner volume of the first movable member such that the first reservoir is disposed in a distal position relative to the second movable member, the first reservoir containing a drug when the second movable member is in its first position relative to the first movable member, the first reservoir being placed in fluid communication with the inner volume of the first movable member when the second movable member is in its second position relative to the first movable member; and a second reservoir at least partially defined by the housing, a portion of the first movable member being movably disposed in the second reservoir, the second reservoir being fluidically isolated from the inner volume of the first movable member when the second movable member is in its first position relative to the first movable member, the second reservoir being placed in fluid communication with the inner volume of the first movable member when the second movable member is moved toward its second position relative to the first movable member to receive a volume of the drug from the first reservoir, the first movable member and the second movable member collectively configured to be moved from a first position relative to the housing to a second position relative to the housing to expel the volume of the drug from the second reservoir. a housing defining an inner volume configured to receive a safety tab; a cartridge assembly, at least a portion of the cartridge assembly configured to be movably disposed in the housing, the cartridge assembly including a first movable member and a second movable member, the first movable member defining an inner volume, at least a portion of the second movable member being movably disposed in the innervolume of the first movable member between a first position and a second position relative to the first movable member, wherein the safety tab is a substantially elongate member disposable within a slot in the proximal end portion of the housing, whereby the safety tab can traverse the inner volume of the housing such that when the cartridge assembly is inserted into the inner volume of the housing, the safety tab engages an outer surface of the cartridge assembly and engage the first movable member to limit at least a distal movement of the first movable member relative to the housing; a first reservoir disposed within the inner volume of the first movable member such that the first reservoir is disposed in a distal position relative to the second movable member, the first reservoir containing a drug when the second movable member is in its first position relative to the first movable member, the first reservoir being placed in fluid communication with the inner volume of the first movable member when the second movable member is in its second position relative to the first movable member; and a second reservoir at least partially defined by the housing, a portion of the first movable member being movably disposed in the second reservoir, the second reservoir being fluidically isolated from the inner volume of the first movable member when the second movable member is in its first position relative to the first movable member, the second reservoir being placed in fluid communication with the inner volume of the first movable member when the second movable member is moved toward its second position relative to the first movable member to receive a volume of the drug from the first reservoir, the first movable member and the second movable member collectively configured to be moved from a first position relative to the housing to a second position relative to the housing to expel the volume of the drug from the second reservoir.