A typical trantrum could go on for days instead of hours, that's number 1. I hope you don't already know that.
The effects of the drugs will likely not match the natural tendancy of people to be awake with the sun and asleep during the moon phase called night. They won't care if the moon and sun were designed and created for them or when the right time to sleep is.
Awarkward and different body language is another reason, which doesn't seem like a big problem. It is, if you consider this could trigger another person to notice they are high on drugs who is extremely against the drug for other reasons besides changes in body language.
Repetitive talking is another reason. It also doesn't seem like a big deal to repeat. Think about all the people who can barely stand to hear other people talking to them. If someone doubles their talking, especially saying the same thing, they double their chances of someone finally telling them to shut up.
Children learning new languages are taught to say hello first. Shut up is an advanced term for new speakers. It is taught last or not all.
Diet changes are another reason. Increased sugar intake has always been associated with comminng down off an illegeal drug high. People are not thinking very clearly when deciding what to eat after not eating for longer than normal. It doesn't matter if you are on drugs or not. Drugs don't undo facts. People need to eat healthy or they won't be able to think about food right. It gets worse after that.
As the drugs wear off people will often drink sugary energy drinks and eat candy.
A diet like that is worse than drugs. It could be a bad combination if you are already in a bad mood and have diabetes or are out of candy or money, or drugs.
Kids and homeless people are always going to eat more candy and cost more than we expect.
Take the time to talk to them and explain why they should follow the rules. Tell them about diabetes.
Or give them money or candy if you are short on time.