* Analysts had seen approval of drug likely
* AcelRx says requests made by FDA "manageable"
* Shares tumble as much as 62.6 pct to $2.00 (Adds CEO comments)
By Manas Mishra
Oct 12 (Reuters) - Shares of AcelRx Pharmaceuticals Inc plunged more than 60 percent on Thursday after the U.S. Food and Drug Administration declined to approve its opioid painkiller Dsuvia.
There were more than 33,000 deaths in the United States in 2015 related to the abuse of the family of heavy-duty painkillers, and the resulting outcry has made the FDA extremely cautious about issuing new approvals.
The FDA last month rejected another opioid painkiller made by Intellipharmaceutics International Inc , asking for more proof of the drug's ability to prevent abuse.
AcelRx said the recommendations in the FDA's letter on Thursday were "manageable" and focused, and that it would resubmit the application for Dsuvia.
The regulator in its complete response letter to AcelRx had requested for additional safety data from the drug and for certain changes in the directions of use to ensure proper administration of the drug.
The change in instructions would be related to clearer communication to healthcare providers to properly administer the tablets, the company said on a conference call.
Analysts had been optimistic that Dsuvia would eventually be approved, citing its limited abuse potential as well as the regulator's decision to not hold an advisory committee meeting.
Dsuvia is a formulation of an opioid drug that is marketed for intravenous delivery, and is meant to be administered orally in patients using the company's proprietary delivery technology.
It would be used in medically supervised settings, such as emergency services and ambulatory surgical centers, an element which traditionally limits the potential for abuse.
The rejection was clearly disappointing and approval had been seen as likely, given the lack of a committee meeting, RBC Capital Markets analyst Randall Stanicky said in a client note.
"Our cash runway is pretty solid, based on the fact that we have $67.9 million in the bank, and we can utilize that to complete the Dsuvia marketing application resubmission," AcelRx Chief Executive Vincent Angotti told Reuters.
The marketing application for its other drug, Zalviso, which the company planned to submit by the year end, would remain unaffected, Angotti added.
Shares of the company plummeted as much as 62.6 percent to $2.00 on Thursday. (Reporting by Manas Mishra in Bengaluru; Editing by Martina D'Couto)