All countries have a separate medical system. In UK there is GP system and you might be required to register formalities.
As for any medicine it is always better to have it prescribed by a doctor as self medication
could be dangerous
Generally common colds subside on their own in 3-5 days and for symptomatic relief warm saline gargles/ steam inhalations work well and for fever paracetamol
is taken sometimes anti allergic are also added for severe rhinitis
(runny nose, nasal congestion
etc for which nasal decongestant drops are also instilled.So depending on symptoms doctors advise medication.Also for dry or productive cough suitable cough syrups are advised. So one has to follow medical systems prevalent anywhere