It is perfectly safe to drink the tap water in Northern Ireland, restaurants are vetted for their hygiene and there are no special instructions regard immunisations. Most generic medicines can be bought over the counter in pharmacies although you will need a prescription from a doctor for sensitive drugs.
Major cities have 24-hour pharmacies but if you can’t find one and are in need of a certain medicine, have your hotel contact a local doctor or visit the emergency ward in the nearest hospital. The UK has a reciprocal health agreement with most countries of the EU so that if you are travelling from Europe and do become ill, you should receive free medical care on producing the necessary health card.
