Its generic name is diphenhydramine and it comes in many different forms some oral and others topical.
But what exactly are said side effects?
The website suggests seeking immediate medical help if you experience any of these symptoms.

And there’s zero chance, today, it would have been approved for over-the-counter sale.
Even if it made it as a prescription medicine, it would be plastered with warning labels."
Therefore, second-generation allergy medicines appear to be far safer as they adhere to more rigorous standards.

Mainly, they don’t induce drowsiness.
