I'm not sure what your character's suffering from but here's a few common medicines available in UK.
Brand names like Anadin - which is paracetemol, Disprin (soluble asprin) and Nurofen (ibruprofen) is popular too. Alka-Seltzer is a hangover remedy which gets rid of headache and settles the stomach.
Not sure what an anti-pyretic is- is it an anti-inflammatory? If so the Nurofen is good for that. If you had a sore ankle or something then you'd take Nurofen to reduce swelling and help with the pain.
Children would take Calpol (paracetamol liquid) or Nurofen liquid.
I'm not too sure about balms- I've used tiger balm for headaches in the past- it's very much an alternative remedy but pretty effective! If you had toothache you can buy Oil of Cloves (very traditional rememdy) or Anbesol which is a liquid- good for teething and other toothaches.
Or there's heat producing creams for aches and pains- Deep Heat being the most well known.
Hope this helps. PM me if you wish and I'll try and find something more specific.