Vel, om ikke jeg husker helt feil så er det visst ikke anbefalt å skyte kodein i det hele tatt.

"Codeine can be administered by many routes, this includes, SC, IM (intramuscularly), as an enema, and orally. Note, codeine can't be administered safely by IV (intravenously) injection as it can result in pulmonary edema (fluid in lungs), facial swelling and other life threatening complications."

Fra erowid, så ville ikke ha satt det intravenøst om jeg var deg :=)