Quote: (If you're comfortable with the technique of giving intra-muscular injections, it's useful to keep a couple of injectable medications on hand as well....
That said, two injectables that are extremely useful to have around are Banamine (flunixin megalumine), which can be used to ease the discomfort of colic, and Acepromazine, a tranquilizer...)
Please don't ever use the injectable Banamine as a IntraMuscle shot. This can create severe abscesses in the muscle. It is best used as an IV shot. You can get a tube of Banamine paste from your vet to keep on hand instead. It does not work as quickly, but is safe if you cannot perform an IV injection.
As for Ace, it's not always the best to use on geldings, as it can potentially cause paralysis in the muscles that assist the horse in extending and retracting the penis from the sheath. A safer option is Xylazine. Keep in mind, that an IntraMuscle injection will require a significantly higher dose that an IV injection for the same effect. There is a product on the market now that again, you can get from your vet, that is a paste tranquilizer.