Multiple Use Disposable Injection Pen

A medication injection pen, comprising:

• a housing;
• a push button at a proximal end of said housing;
• a dose set knob (DSK) comprising at least one internal tooth and a ring of DSK ratchet teeth on said dose set knob;
• a driver including at least one external tooth and a ring of driver ratchet teeth on said driver,
• a clicker operatively engaged between said dose set knob and said driver having at least a DSK ratchet arm for engaging said DSK ratchet teeth and at least a driver ratchet arm for engaging said driver ratchet teeth;
• wherein said driver is prevented from rotating with said dose set knob while moving axially with said dose set knob during dose setting and dose correcting, and when said push button is depressed, said clicker is moved distally and pushes said driver distally such that said at least one external tooth of said driver engages said at least one internal tooth of said dose set knob thereby forcing said driver to rotate with said dose set knob during an injection.