RUSSIA - Oct. 30 - Health Ministry Names Gas Used In Theatre Siege.

Health Minister Yuri Shevchenko tells a news conference that the gas that killed 117 hostages in Moscow on Oct. 26 was an opiate-based form of the drug fentanyl. (This comes days after Western experts first identified the substance). Shevchenko acknowledges that the gas was based on derivatives of fentanyl, a commonly used anaesthetic, saying it was deployed to "neutralise the terrorists". Despite the large number of fatalities, he denies that doctors were ill-prepared to handle the consequences for the hundreds of hostages in the theatre, and stresses that the use of the gas did not violate the international ban on chemical weapons. At the same news conference, Mikhail Avdyukov, the Moscow prosecutor, pledged a thorough investigation into the deaths of the hostages. According to US experts, fentanyl belongs to a group of medicines called narcotic analgesics that suppress breathing. While similar to morphine and Demerol, medical specialists said fentanyl is 100 times more potent than morphine. A normal dosage goes to the brain but is then redistributed quickly to the rest of the body, making it a short-acting anesthesia. But a larger dose does not redistribute as well, remaining concentrated in the brain and shutting down respiratory functions.