Used to be available in Thamel, but no longer. (At least, I tried a few years ago and was told by pharmacy they are no longer available.)
There are other good cough suppressants that do not have the constipation (or legal) issues of codeine, such as Dextromethorphan Hydrobromide 20mg.
"I assume that Dextromethorphan Hydrobromide is readily available at any pharmacy in Kathmandu?"
I would NOT assume this. I buy in Canada and bring with me. In general, I would get trusted over-the-counter meds at home (assuming they are not like codeine, in terms of legal issues).
Thai Laws, from initial reading, apply only if one clears customs. If one's transit is only through the transit lounge then codine in checked luggage is ok!
I will be reading this again and checking with Thai air but it seemed clear in the wording....I dare say it would be different if one was carrying items illegal at destination etc.
Codine works for a number of old sporting injuries for me when one must simply "crack on"
I am more than happy to corrected of course re customs.Edited: 18 October 2018, 06:39
John, in practice, I think you are correct.
That is, very unlikely it is an issue if only transiting through BKK.
(Indeed, highly unlikely to be an issue even if you are staying multiple days - - I did this in 2014 and 2016 before I found out my A-C&C tabs (which were OTC in Canada until this year) were actually not allowed.)
But who wants that worry/hassle!
It may still be technically illegal even if transiting BKK, aa bags are on Thai soil. Who knows. Again, highly unlikely to be an issue. Still, I switched to a better different/legal (and, as it turns out, better) cough suppressant.
Dextromethorphan Hydrobromide is available over the counter under a name Robitussin DM
DH available as other brands (including cheaper store-brands) and different formats (pills, liquids). We find pill format easiest for trekking.