Adasuve, which delivers an older antipsychotic drug called loxapine, passes through the lungs and into the bloodstream faster than a typical pill. Loxapine is available as an oral drug for schizophrenia.

The company said the product will include a boxed safety warning about potentially dangerous side effects including the potential for fatal bronchial spasms in people with asthma or chronic obstructive pulmonary disorder and a higher risk of death in elderly people with dementia-related psychosis.

Adasuve use will be restricted to mitigate the potential harm of bronchial spasms, Alexza said.

The FDA also required Alexza to conduct a large post- marketing clinical trial of patients to assess the real-world use of the drug.

"We believe that the ability to deliver medications rapidly and non-invasively will be important for patients and the professionals who care for them," Chief Executive Thomas King said in the statement.

Three injectable drugs, Bristol-Myers Squibb's Abilify, Eli Lilly's Zyprexa and Pfizer Inc's Geodon, are currently approved to calm patients with schizophrenia or bipolar disorder.

Adasuve, Alexza's most advanced drug, will be available for commercial launch early in the third quarter of 2013, the company said.

Earlier this month, European health regulators recommended approval of Adasuve.

The FDA denied approval to Adasuve in May, after it found deficiencies at the company's Mountain View, California manufacturing facility during an inspection.

The company's shares fell 12 percent in the after market trading after the trade was halted at $5.79 before the drug- approval announcement.

(Reporting by Prateek Kumar; Editing by Sreejiraj Eluvangal)

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