Let me preface this by saying that DD had a lot more tantrum-like behavior without her meds, so it may simply be a sign of a bad week (or a lousy night's rest because she did refuse to go to sleep when I sent her at 8:30p ... and was still up messing around with her toys & window blinds at 10:30p) but here goes:

Over the past several weeks, DD has had a few destructive tantrums both at home and at school.

At home, she has broken her bedside lamp (I still don't know how, but she snapped the bulb socket out of a PBK lamp), had a fit about not understanding a new subtraction task at school (broke a pencil & tore the cover of her math book), acted out for 90 minutes at a Girl Scout meeting with another troop (apparently, she was upset that another child was "yelling" in the space - DD's school cafeteria), acted out for 20 minutes at another off-site meeting (while visiting a food bank to hear the charitable organization's director speak, DD proclaimed she was bored after being told off for trying to head to a 2nd floor because she was "just so curious" then she started head-butting me and flipping the lights on & off until she finally asked to use the restroom) and had another fit where she detached the glass cover of her ceiling fixture and dropped it (it shattered on her bedframe, spewing glass all over her bedding, her detritus-covered floor, and most of her room.)

Today, she got into an argument with a child (who has been a problem for her for at least a week, perhaps more) about a board game she and another classmate were playing, which resulted in both boys teasing her ... and the original child who'd begun the issue ended up with a bite. (He claims DD bit him. While I'd like to believe that she didn't, and she says she didn't, I wouldn't put it past her to bite or scratch this kid.)

Most of her tantrums seem to happen when things change from her expected pattern - the new location for the Scout meetings, taking her tablet (or a game/app on the tablet) away, being taunted/teased, having a substitute teacher, etc.

We have been trying to help her feel empowered enough to speak with whoever the on-site grownup is when incidents happen at school.
For things at home, I try to lay out clear expectations for her behavior BEFORE we go into a new situation, but she isn't always a great listener. (And, well, she sometimes can't help it if her meds have worn off.)

DH and I are trying to decide if these are enough evidence to call her doctor and try to tease out if this is a medication issue or just a disrupted schedule issue. She does have her physical coming up in a couple of weeks, and it seems that a lot of her acting out has to do with being kept indoors (it's been bitterly, dangerously cold outside lately), so it may just be excessive energy.

How do other folks deal with this?