Up to 800 health centers have been approved to administer Johnson & Johnson's new ketamine-like depression drug, which was cleared for sale last month, and patients are already using it, the company said Tuesday.

Spravato, or esketamine, won federal approval March 5 for treatment-resistant depression. It's similar to ketamine, a sedative known as the club drug "Special K" that's increasingly being studied and used to treat depression.

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Spravato's side effects include sedation and dissociation. It also carries the potential risk of misuse and abuse. Acknowledging these factors, the FDA stipulated Spravato must be administered in a medically supervised health-care setting where patients are monitored. Pharmacies, doctor's offices and clinics also need to be certified.

In a little more than a month, J&J has certified up to 800 sites, putting the company "well on track" with its plans for the year, Jennifer Taubert, executive vice president of pharmaceuticals, told analysts on a call Tuesday discussing first-quarter earnings results. She said a number of patients have received their first dose, with some receiving multiple doses.

"So we believe that we're off to a very, very strong start with Spravato, and that it is going to be an important growth driver for us," she said.