I think Customs has better things to worry about, than a few codeine tabs in someone's purse.

Personally I do not worry too much about carrying personal use quantities of medication when I am travelling. Sometimes I will dump my various pills into a vitamin bottle, but that's more to cut down on the number of bottles rattling around in my toilet kit than a real effort to hide what I'm carrying. I never carry more of anything than I am likely to need while I'm travelling.

I fly internationally at least once a month on average, and I have never once had a customs agent check my meds, prescription or otherwise. Not when I'm leaving the USA, not when I'm clearing customs in Madrid or Stockholm or Jakarta, and not when I'm clearing customs again back home.

I've had my luggage THOROUGHLY searched only twice in 20 years, by US customs, but they were more concerned with counting the cash I had with me to see if I was bringing in more than the allowed $10,000, and checking my receipts to see if I was smuggling shoes or something. They barely gave a second look to my various prescription bottles, vitamins, and assorted blister packs of IOP products that I routinely travel with.

The only scare I ever had in this regard was quite recently. While I was waiting by the luggage carousel for my bags to show up, some customs guys came around with the sniffer dogs, and the dogs went nuts for my carry-on, like it was full of hashish or something. I had several scripts with me, including hydro from an IOP, plus some blister packs of Ritalin and Ambien, plus some antibiotics and some Prednisone I was taking for an infected rash.

Turned out it was the Prednisone that the dogs were after, not the hydro! When they saw the label on the bottle the customs guys just laughed and waved me on.