Before taking amoxicillin,tell your doctor and pharmacist if you are allergic to amoxicillin; penicillin antibiotics; cephalosporin antibiotics such as cefaclor, cefadroxil, cefazolin (Ancef, Kefzol), cefepime (Maxipime), cefixime (Suprax), cefotaxime (Claforan), cefotetan, cefoxitin (Mefoxin), cefpodoxime, cefprozil, ceftaroline (Teflaro), ceftazidime (Fortaz, Tazicef, in Avycaz), ceftibuten, ceftriaxone, cefuroxime (Ceftin, Zinacef), and cephalexin (Keflex); any other medications; or any of the ingredients in amoxicillin capsules, tablets, or suspension. Ask your pharmacist for a list of the ingredients.tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: allopurinol (Lopurin, Zyloprim), other antibiotics, anticoagulants ('blood thinners') such as warfarin (Coumadin, Jantoven), oral contraceptives, and probenecid (Probalan, in Col-Probenecid). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.tell your doctor if you have mononucleosis (a virus; also called 'mono') and if you have or have ever had kidney disease, allergies, asthma, hay fever, or hives.tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking amoxicillin, call your doctor.if you have phenylketonuria (PKU, an inherited condition in which a special diet must be followed to prevent mental retardation), you should know that some amoxicillin chewable tablets are sweetened with aspartame that forms phenylalanine.