The most common side effects of AURYXIA, when it is used to lower phosphorus in the blood for adult patients with CKD on dialysis, include: Diarrhea Nausea Constipation Vomiting Cough AURYXIA contains iron and may cause dark stools, which are considered normal with oral medications containing iron. For more information ask your healthcare provider or pharmacist. Tell your healthcare provider if you have any side effect that bothers you or that does not go away. Call your healthcare provider for medical advice about side effects. You may report suspected side effects to Akebia Therapeutics, Inc. at 1-844-445-3799 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.