Blood-thinning medications include medications such as Aspirin, Marcoumar/Warfarin and Xarelto. Since these delay clotting and prolong bleeding, some treatments cannot be carried out while you are taking these medications. Therefore, one should not take Aspirin (e.g. for a headache or flu symptoms) for a week prior to treatment. If blood thinners have to be taken regularly due to cardiovascular disease, they should not discontinued (even temporarily) without prior consultation with the attending physician or your family doctor.