A painkiller and a piña colada are both classic tropical cocktails that include rum, pineapple, and coconut, but a painkiller also includes orange juice and is garnished with ground nutmeg. A piña colada is often blended and served as a frozen cocktail, whereas the painkiller is served over ice. Both drinks taste sweet and tropical, but the painkiller cocktail tastes more citrusy with a hint of spice from the nutmeg garnish.