Advice for DXM first time trip

[Red Fox]

In the UK (where SWIM lives) there is an over-the-counter cough syrup that is for children aged 1 to 12 years old. It is called "Children's Coughs & Colds" and is marketed by Benylin. On the box which contains the bottle inside it says "Contents" and all it says is that each 5ml of syrup contains Dextromethorphan Hydrobromide 5mg and Triprolidine Hydrochloride 0.625mg. How much of the syrup in a bottle should be taken and is the other substance potentially dangerous at all??? Would SWIM need to extract to achieve effects of the DXM or could SWIM just drink the whole syrup?