Doctors welcomed federal approval this week of a new, fast-acting nasal spray for depression. But also they expressed concerns about its cost and long-term effects, as well as the logistics of administering it in accordance with safety requirements.

The new drug, esketamine, made by Janssen Pharmaceuticals, won approval from the Food and Drug Administration on Tuesday for people who have received little or no relief from other antidepressants. The F.D.A.’s decision followed months of anticipation; esketamine, which will be marketed under the name Spravato, is the first prescription for depression derived from ketamine, an old and widely used anesthetic.

The recommended course of the newly approved drug is twice a week, for four weeks, with boosters as needed, in conjunction with one of the commonly used oral antidepressants. But both esketamine and ketamine have side effects, including out-of-body sensations and hallucinations, and have the potential for abuse. The F.D.A. issued strict safety requirements: Doses must be taken in a doctor’s office or clinic, with patients monitored for at least two hours, the experience must be entered in a registry, and patients should not drive on the day of treatment.

“These issues raise barriers,” said Dr. Erick Turner, a psychiatrist at Oregon Health & Science University. “People have to come in twice a week to the hospital and stick around for two hours being monitored. So you’ve got to have space for them, and the question is, where? The waiting room’s not going to work — in the clinic somewhere, which can be hard to find. And then someone’s got to drive them home.”