Alexza Pharmaceuticals ($ALXA) has won a long-sought approval for an antipsychotic drug called Adasuve from the FDA. The company plans to push the inhaled med onto the U.S. market early in the third quarter of 2013.

U.S. regulators stamped an approval of Alexza's inhaled version of the antipsychotic drug loxapine for adults struck with agitation linked to schizophrenia or bipolar disorder. The approval comes with warnings about serious adverse events such as potentially lethal bronchospasms and increased risk of death in elders with dementia-related psychosis.

The product will only be available through a REMS program to limit any harm to patients, and doctors are being warned against prescribing Adasuve for patients with lung ailments such as asthma and COPD.

Alexza filed for FDA approval of Adasuve three years ago, and as of September 30 the company had burned through $324.3 million during its hunt for its first product approval, according to its quarterly financial report. U.S. regulators granted that first approval last week and an EMA panel backed approval earlier this month for the EU market, raising the odds of Adasuve hitting shelves in Europe next year as well.

Amid its journey to an FDA approval, Alexza overcame multiple regulatory hurdles. The FDA denied Adasuve in October 2010 with a complete response letter. After the company took another shot with a submission in August 2011, the FDA handed the company another CRL this May for what the company presented as issues related to the device used to deliver its inhaled formulation of loxapine.

Adasuve isn't expected to climb to blockbuster sales levels like previous antipsychotics such as Zyprexa and Abilify. As quoted by Bloomberg, Roth Capital Partners analyst Scott Henry estimated U.S. sales of $207 million in 2016 for the product.

- here's the release

- see Bloomberg's article

Correction: The story was corrected to state that Adasuve will be commercially available in the third quarter, not the first quarter, as initially reported. We regret the error.