Keppra, or levetiracetam, is an antiepileptic drug. It is popular, safe, effective and has minimal side effects. But one important (uncommon) side effect is rage.
LEV was rated as very effective by 40% of the patients. In contrast to
only 9% of the controls, a considerable number of patients reported a
behavioral change while taking LEV (12% very negative, 25% negative,
16% positive, 6% very positive). Negative ratings were due to loss of
self-control, restlessness, sleep problems, and, most importantly,
Keppra rage can be a very big deal. It can happen to conscious, normal, intelligent people and such people might be aware that their tempers are somehow very short.
I am desperately seeking advice. I am engaged and my fiance has
epilepsy. We have been together 5 years, and in the past couple of
years since he started taking keppra, he has drastically changed. Most
of the time, he is his normal self, the person I love, but he often
gets extremely irritated and freaks out, yelling and cursing, not just
at me, but at other people as well. He seems to have no ability to
cope with the slightest issues that would roll of most people's back
without so much as a second thought. Even worse is that every so often
(once a month or so) he flies into these uncontrollable rages that
absolutely terrify me. We will be having a normal conversation, both
in great moods, and suddenly he is kicking walls and throwing things
with a blank stare like he isn't even really there. It really scares
me and this never happened before the keppra. He isn't honest with his
doctor about the side effects because he is too afraid to get off
keppra and try something else because he thinks it will trigger
seizures during the transition
You could use this for your story. Tweak keppra into a fictional drug - perhaps an anti seizure drug which did not make it to market because despite its efficacy, the incidence of rage was near 100%. When your protagonist slips it to the other characters, they become extremely aggressive and short tempered. Careful what you wish for, dude!