The US Food and Drug Administration approved Janssen Pharmaceuticals Inc.'s esketamine on Tuesday for treatment-resistant depression; the drug is the chemical cousin of ketamine, the powerful anesthetic that has been used illegally as the club drug Special K. It will be sold as Spravato. It's for patients who have tried at least two other medications without success, and it should be taken with an oral antidepressant. There has been a longstanding need for additional effective treatments for treatment-resistant depression, a serious and life-threatening condition," Dr. Tiffany Farchione, acting director of the Division of Psychiatry Products at the FDA's Center for Drug Evaluation and Research, said. Spravato is a nasal spray administered by an approved health care provider in a doctor's office or a medical clinic. It may also be self-administered but only under the supervision of a care provider and cannot be taken home. Depending on the severity of the patient's depression, it is given either once a week or once every other week. The drug is rapidly acting, so it starts working faster than other antidepressants, according to Janssen. It works by restoring brain cells in patients with treatment-resistant depression. Currently available treatments for major depression are ineffective in 30% to 40% of patients. The drug was designated as a breakthrough therapy in 2013, a status intended to "expedite the development and review of drugs for serious or life-threatening conditions," the FDA said at the time.