Colostrum has shown no drug interactions thus far, however, you may find a more pronounced effect in other supplements you may be taking, especially if the other supplements are intended for the GI tract. It is always recommended you consult a physician before starting colostrum or any other supplement.
Due to the healing effect colostrum has on the digestive tract, all substances taken simultaneously, including natural and conventional medicines will probably be absorbed better by the body, which is reflected int he pronounced effect. You may find you can reduce the quantity of other medications. Please discuss this with your general practitioner.