Hello PZ world!
Everyone knows about beta-blockers, which decrease fear and panic.
I suggest to add an opportunity to take Beta2-adrenergic agonists (in Russian β2-адреномиметики) which have an interesting effect. Beta2 agonists help to catch a second wind very fast, because they increase sustainability to muscle loading. Its negative aspect is addiction may also be included into the game mechanics.
Thank you for reading!
Good luck!