It's all about licensing.
OTC codeine isn't licensed for sale to certain people, including pregnant women. When your doctor prescribes it, he or she is giving it out under the licensing that applies for prescribd medications.

I may be missing something though.
(lympicita_ie, Tue 16 Mar 2010, 20:47, 1 reply)

Yeah, makes sense.
It's perfectly reasonable, it's just that I only have 3 x 30mg codeine to do me for the next 36 hours (plus some ineffective tramadol that makes me vomit).
( crackhouseceilidhband Fuck off back to Mumsnet, Tue 16 Mar 2010, 20:50, closed)

Have you tried
Putting on something loose fitting and trying another pharmacy?
(Puddle of Sugar was still wallpapering on, Wed 17 Mar 2010, 14:12, closed)