Welcome to just Answer. If you routinely use Anadin Extra (aspirin/paracetamol/caffeine) for pain relief, there is no reason you cannot take it along with your antibiotic. They will not interfere with one another. Be sure to take the Anadin with food to help prevent stomach upset, and drink lots of water while taking both products. Hope you feel better soon.
Yes, it will not interfere with your antibiotics.