Pre-treatment with corticosteroids (prednisone) and antihistamines (diphenhydramine) may decrease frequency/severity of allergic reactions. May exacerbate sickling in sickle cell disease. Associated with nephrotoxicity. Contraindicated in severe hepatic impairment. Caution in mild-to-moderate liver disease, hypertension, debilitated patients, pheochromocytoma, previous reaction to contrast dye or iodine-based contrast media, asthma, renal impairment or predisposed to contrast-induced nephrotoxicity (diabetes, the elderly, concomitant medications such as metformin). Never use for intrathecal administration (acute renal failure, cardiac arrest, cerebral hemorrhage, coma, death, paralysis, and seizures can occur).