Image: 4 panels organized in a rectangle following a sequential order like a comic strip. The first panel is of a man with a very serious face stating, "Hey man, got any diphenhydramine?" The second panel is a grainy picture of the actor Robert Downey Jr. with a slightly inquisitive face and saying, "What's that?" The third panel is an identical copy of the first image and saying, "Benadryl the allergy medicine." The fourth and final panel is a grainy picture of Bobby rolling his eyes and taking a deep breath.
Edit: Tony Start -> Robert Downey Jr. I didn't know that Tony Stark was a character Robert Downey Jr. played 🤦♂️
Yes but. From what I've heard, sometimes when switching to a generic, there might be subtle differences in manufacturing that affect how an individual absorbs it. For something minor - an off the shelf pain killer - probably not a problem. For someone where it's imperative that they maintain a certain blood level of the drug, some caution is a good idea.