Emergency valve for providing an alternative medication supply to a patient in case regular drug supply is disturbed, comprising a housing encompassing a chamber sealed by a membrane; a piston equipped with an infusion needle moveable in said chamber from a resting position in which the infusion needle is retracted to a forward position in which the infusion needle pierces said membrane sealing the chamber; said chamber being in fluid communication with an auxiliary opening of a regular drug conduit, said piston having a connecting unit connected to the infusion needle for connecting the infusion needle to the auxiliary opening of the regular drug conduit and for allowing drug flow from the regular drug conduit through the infusion needle when the piston and the infusion needle are in a forward position, and for blocking drug flow when the piston and the needle are in a resting position; a pressure sensitive system for moving the piston from the resting position to the forward position comprising: a surface of said piston being configured such that upon pressure increase in the regular drug delivery conduit due to blockage, said piston together with said infusion needle moves from the resting into said forward position; so that the connection unit is moved forward from a resting position between sealing rings (16, 17) towards the auxiliary opening of the regular drug conduit, so that drug can be supplied via the infusion needle which punctures the self-sealing membrane, thereby generating a bypass for drug supply, a return spring provided in a chamber of the housing, the return spring being connected to the moveable piston assisting to move said piston with the infusion needle into its resting position, such that upon pressure decrease, the piston and the needle are retracted towards the resting position, and the alternative drug supply is stopped as the connecting unit is closed by the first sealing ring, and a supporting line interconnecting the chamber containing the infusion needle and the chamber containing the return spring. a housing encompassing a chamber sealed by a membrane; a piston equipped with an infusion needle moveable in said chamber from a resting position in which the infusion needle is retracted to a forward position in which the infusion needle pierces said membrane sealing the chamber; said chamber being in fluid communication with an auxiliary opening of a regular drug conduit, said piston having a connecting unit connected to the infusion needle for connecting the infusion needle to the auxiliary opening of the regular drug conduit and for allowing drug flow from the regular drug conduit through the infusion needle when the piston and the infusion needle are in a forward position, and for blocking drug flow when the piston and the needle are in a resting position; a pressure sensitive system for moving the piston from the resting position to the forward position comprising: a surface of said piston being configured such that upon pressure increase in the regular drug delivery conduit due to blockage, said piston together with said infusion needle moves from the resting into said forward position; so that the connection unit is moved forward from a resting position between sealing rings (16, 17) towards the auxiliary opening of the regular drug conduit, so that drug can be supplied via the infusion needle which punctures the self-sealing membrane, thereby generating a bypass for drug supply, a return spring provided in a chamber of the housing, the return spring being connected to the moveable piston assisting to move said piston with the infusion needle into its resting position, such that upon pressure decrease, the piston and the needle are retracted towards the resting position, and the alternative drug supply is stopped as the connecting unit is closed by the first sealing ring, and a supporting line interconnecting the chamber containing the infusion needle and the chamber containing the return spring. a surface of said piston being configured such that upon pressure increase in the regular drug delivery conduit due to blockage, said piston together with said infusion needle moves from the resting into said forward position; so that the connection unit is moved forward from a resting position between sealing rings (16, 17) towards the auxiliary opening of the regular drug conduit, so that drug can be supplied via the infusion needle which punctures the self-sealing membrane, thereby generating a bypass for drug supply, a return spring provided in a chamber of the housing, the return spring being connected to the moveable piston assisting to move said piston with the infusion needle into its resting position, such that upon pressure decrease, the piston and the needle are retracted towards the resting position, and the alternative drug supply is stopped as the connecting unit is closed by the first sealing ring, and a supporting line interconnecting the chamber containing the infusion needle and the chamber containing the return spring.