What drugs can be used if allergic to codeine?

Tramadol. http://www.uic.edu/pharmacy/services/di/faq/codeine.php.
Codeine allergy. There are many alternatives. Just because you are allergic to Codeine dose not mean that you are allergic to hydrocodone, Oxymorphone , oxycodone. Depending on the allergy morphine may be acceptable. Synthetic opiates demerol, (meperidine hydrochloride) alfentanyl, sufenta, or fentanyl are perfectly safe , .
Codeine allergy. Its hard to tell which drugs can be used. However, any drugs containing Codeine can induce allergic reaction in patient allergic to codeine.