Ok my Gourami has an ulcer on his side that despite much treatment doesn't seem to heal and is getting worse. I'm going to make one last attempt at treating it.

I have the following medicines:

Melafix (broad spectrum antibiotic)
Interpet no 9 (anti internal bacteria)
Protozin (antibacterial- used this a week ago and it had absolutely no effect)
Wormer plus (anto parasite)

Which should I use?

none, you are wasting your time with those medications.
Ulcers are caused by bacteria.
If you want to try and treat it then go to a fish vet and get some tetracycline or oxytetracycline. It kills most bacteria including the filter bacteria so use it in a bare tank with lots of aeration.
Sorry to put this so bluntly, but it will cost you more to visit the vet than to replace the fish.

Hmm, well i wont go to the vet but maybe i'll just try those lame english meds so i feel like i'm doing something and although he's my favourite and oldest fish if he dies he dies it seems there's not much you can do to help sick fish!

some sick fish you can treat, but ulcers are one of the hardest things to treat.

I had a clown fish that developed an ulcer,
Tried all the medications you have listed.
None worked. That in it self was not cheap.

I have to agree with colin you tryed all the uk meds by jbl fluranol, you need antibiotics.

How long do they take to die of ulcers? He seems fine in himself.. will he die of a secondary infection?

Thanks for the replies!

http://www.fbas.co.uk/Ulcers.html

Great link as always Wilder, thanks. It says that once the bacteria has been treated the ulcer can take 2-8 weeks to heal, it's been about 2 weeks so maybe he will get better it's just taking time. Either way I am treating him for the sake of it with an anti bacterial, it's only a 2 dose 4 day course so i will return him to the main tank over the weekend and then just leave him be and hope it heals!

Good luck.

Thanks

could try esha 2000
available in the uk