The first thing to remember is that OTC medications come with instructions for a reason.
These instructions are tested for the most effective safe doses.
Yes, many of these medications can be prescribed at higher doses.
But the reason why it takes a doctor’s prescription for a higher dose is because tests showed that higher levels need to be under a doctor’s supervision in order to avoid issues.
And this is especially true if you have any health issues that you’re already taking medication to cope with.
Interactions between prescribed medications and OTC medications can be disastrous if you don’t check with a doctor or pharmacist for compatibility.