My son travels with 2 epipens, a bottle of Benedryl (larger than 4 ounces), inhalers, albuterol for his nebulizer (plus a portable battery powered nebulizer). You don't need any doctor's note for the US or anything. Any medications are also exempt from the liquid limit rule.
Always carry ALL your medications on you! Also, if you have one carry on that is only meds, it cannot count against your carry on limit on planes (so if you have a cpap machine or something, to keep in mind). I put all our meds in one carry on bag for our trips.