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Pain-Killing Nose Spray Tested
December 26, 2002 01:00:17 PM PST, Reuters
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An inhaled version of methadone may be a reasonable alternative to oral and intravenous versions of the pain-killing drug, according to a new study. However, the formulation used in the study needs to be modified, researchers say, since it irritated the nose.

Methadone, like morphine, is a type of drug called an opioid. Methadone is often used to treat heroin addiction, but the medication may also be used to relieve chronic pain. For people with cancer-related pain, oral opioids, particularly controlled-release morphine, are standard therapy.

For most people with moderate to severe cancer pain, oral opioids are effective, but some patients need other intravenous or inhaled forms of the drugs to keep pain under control. Methadone is cheaper than other opioids and has a long-lasting effect, but a nasal form of the drug is not available.

In the new study, which is reported in the journal Clinical Pharmacology & Therapeutics, researchers tested a nasal formulation of methadone in eight healthy men and women. Participants first received an oral or intravenous dose of methadone, then they received a dose of the drug from a nose spray.

Dr. Ola Dale of the Norwegian University of Science and Technology in Trondheim, Norway and colleagues found that methadone delivered through a nose spray was absorbed almost as rapidly as intravenous methadone. The duration of its effect was comparable to that of oral and intravenous versions of the medication.
However, patients experienced a burning sensation when they used the spray.

Nose sprays may be an alternative for methadone, but "improved formulations are desirable to reduce nasal irritation," the authors conclude.

SOURCE: Clinical Pharmacology & Therapeutics 2002;72:536-545.