Xywav and Xyrem have some similarities and differences. Both drugs are used to treat narcolepsy symptoms of excessive daytime sleepiness and cataplexy. But Xywav is also approved to treat idiopathic hypersomnia.Both Xywav and Xyrem contain the active ingredient sodium oxybate. Xywav also contains three other active ingredients: calcium oxybate, magnesium oxybate, and potassium oxybate.However, Xywav contains less sodium (salt) than Xyrem. For this reason, Xywav is generally a safer option for people following a low sodium diet for conditions such as high blood pressure or kidney disease.Both Xywav and Xyrem have boxed warnings for the risks of central nervous system (CNS) depression and misuse.* Due to these risks, the drugs are available only through the Xywav and Xyrem risk evaluation and mitigation strategy (REMS) program. The healthcare professional prescribing these drugs and the pharmacy dispensing them must be certified by the REMS program.If you have other questions about how Xywav compares with Xyrem, talk with your doctor or pharmacist.* A boxed warning is the most serious warning from the FDA. To learn more, see the “Xywav precautions” section.