An intranasal form of morphine (Rylomine, Javelin Pharmaceuticals) provides similar pain relief, is easier to administer, and is as safe as intravenous morphine in treating moderate-to-severe pain following surgery, investigators reported this week at the 22nd Annual Meeting of the American Academy of Pain Medicine in San Diego.
Rylomine is also less subject to abuse than conventional forms of morphine, presenter Dr. Daniel Carr, from Javelin Pharmaceuticals in New York, told Reuters Health.
The morphine in Rylomine is compounded with an agent that prolongs its contact with the nasal tissue, thus permitting better absorption into the bloodstream, the researcher explained.
“By staying longer in contact with the nasal mucosa, it gives blood levels indistinguishable from a 20-minute IV infusion of morphine,” he added.
Carr and colleagues performed a randomized, double-blind study to evaluate the safety and efficacy of Rylomine on 4-hour total pain relief. Groups of 23 to 46 patients were randomly assigned to varying doses of Rylomine or to IV morphine or placebo.
The experimental intranasal form of morphine worked just as well as the IV form, the authors report.
Local side effects associated with nasal administration were mild and included bad taste, nasal congestion, nasal discomfort, throat irritation and sneezing. Local adverse events associated with IV administration included burning, itching, and rash at the infusion site.
General adverse events related to active drug, regardless of route of administration, were dose related and consistent with morphine’s pharmacologic effects, including fainting, dizziness, nausea, and sedation.
Carr pointed out that the nasal spray can be easily self-administered, “instead of having a complicated patient-controlled analgesia machine that requires programming - and which can be misprogrammed.”
He noted that the product they are developing is intended to have a single 7.5-mg dose in a sprayer, with nothing left in the sprayer once the dose is used.
“Perhaps a bigger concern than ‘does it work?’ is its potential for abuse,” he continued.
Carr explained that among opiate abusers, “the least amount of morphine equivalent they want per hit is 25 mg to achieve a high. The maximum amount of absorption you could get with our device is about 20 mg.” That’s because “the nasal membrane can only hold a limited amount of spray before it starts dripping off.”
Consequently, “even if they had room full of the stuff, it would be nearly impossible to get the desired euphoria by using this method.”
He noted that his group is about to embark on phase III trials. They will be seeking approval in the US and Europe for the drug to be administered in a medically supervised setting for acute, moderate-to-severe pain.
Revision date: June 22, 2011
Last revised: by Jorge P. Ribeiro, MD