An autoinjector is provided that includes an actuator assembly having an actuator body and a relief valve assembly. The actuator body includes a receptacle, an open distal end in fluid communication with the receptacle, and a channel in fluid communication with the receptacle. The relief valve assembly includes a first timing member and a second timing member. The first timing member is movable between a primary position and a secondary position under the influence of a force. The second timing member is movable between a first position directly engaged with the first timing member and a second position spaced from the first timing member.