Most of them. Haven't needed to take the GI meds other than cimetidine, which I take not just for my guts and acid reflux but also for its cytochrome P450-3A4 inhibitor properties so as to allow my prescription morphine and oxy to act for longer and be more bioavailable.
Found a pharmacy today that carries both a tincture of opium cough mixture over the counter, although I bought none, because they also stock codeine syrup (600mg per bottle, I think the bottle capacity is 200 or 250ml, can't remember which.), so I bought a bottle of that instead. There are two kinds, both the same strength, but one is sugar free flavoured with vile synthetic orange, its disgusting tasting, whilst the other one tastes lovely, full of sugar though, and flavoured with a little chloroform. That I find most surprising as its somewhat hepatotoxic, indeed I was shocked to discover it in this day and age being in a medical product meant for ingestion.
Just drank the equivalent of half a gram of codeine about half an hour to 45 minutes ago, and am just beginning to start feel a lovely warm glow and getting all itchy. Took it with a shot of 60-70mg oxy. Mmmm....thats certainly done wonders for my cough. Its been driving me nuts, caused partly by acid reflux and my throat has been absolute murder all week, had to leave part of my sausages with last night's sausage, fried eggs chips and beans supper because it hurt too much to swallow.