The canisters that Eva has found are nitrous oxide, a gas usually transferred into balloons before being inhaled recreationally. The drug has anaesthetic and depressant properties, causing a brief feeling of euphoria – which usually manifests as feeling happy, relaxed and giggly, and gives rise to the popular name “laughing gas” – as well as light headedness and dizziness. Some users experience headache, nausea and hallucinations.

Although the sensation is relatively brief, nitrous oxide is not without its risks and pharmacy teams can help raise awareness:

• Inhaling the gas directly from the canisters is dangerous because it is under pressure and can cause physical injuries
• Some people try and prolong the effect by inhaling it in an enclosed space, for example, with a plastic bag over their head, which obviously carries further risk
• Another way in which people may try and prolong the effect is by using several canisters in a short space of time, but this can cause loss of consciousness or suffocation due to the brain cells being starved of oxygen
• Regular or heavy use of nitrous oxide can deplete vitamin B12 levels, leading to anaemia and nerve damage
• Mixing drugs is never a good idea, but combining nitrous oxide with alcohol brings with it specific risks because both are depressants and so the effects on heart and breathing rate, etc. can be potentiated.