Pen epinephrine side effects?

C priors...: When used properly, like when have an anaphylaxis (acute allergy reaction) to something very allergic to (bee sting, peanuts, shellfish..), it will reverse the potentially fatal effects of the reaction --severe bronchospasm of lung causes tight breathing, swelling of the throat (preventing air from getting into lungs), ...Then it should not have any side effects. Perhaps some sense of palpitation..