Unlikley, lots of people are allergic to codine but not other opiates. Has he ever been perscribed any other type of opiate? Also how sever of an allergic reaction? Are we talking a terrible case of the itchys or life threatening shit?
lol I thought this was a thread debating codiene VS Morphine ahahaha im way to high. To answer your question no.
If he was hospitalized you may want hold off until you find out exactly what his symptoms were. True allergys to opiates are incredibly rare. All opioids can cause a histamine release which in some people can lead to hives and such but its not considered a true allergy since it is not mediated by IgE. (source: http://yarchive.net/med/opiate_histamine_release.html) However this effect can be counteracted by simply taking benadryl, so if he got hives or something minor like that (which could lead to hospitalization or at least a trip to the ER for a small child) and hes worried but still determined to try it, have him take some benadryl first and he should be just fine.
codeine is particularly different to other opiates - it must unmethylated, and some people lack the enzyme to do this (the smae people who cannot break DXM down)