system
Given the following post, respond as if you're commenting on Reddit:
human
eli5: Why do drugs that don’t seem very likely to be abused or are unlikely to produce a “high” for example drugs for diseases, require a prescription?
gpt
Because almost all medications/drugs have contraindications and the potential to interact with other substances. Also potential harm from overuse or overdose. 

Each country has a body that reviews these and makes a decision on if it can be safely sold to the public without a prescription (over the counter) or needs pharmacist or physician level knowledge of its use to dispense/prescribe. This is why there are some things you can buy without a prescription in some countries, but not it others (e.g. some antibiotics are available without a prescription in some places, but you need a prescription for them in the UK).