New River says NRP104 unlikely to be abused intravenously

By Elaine Rigoli

Tampa, Fla., June 20 - New River Pharmaceuticals, Inc. said a clinical abuse liability study of NRP104 (lisdexamfetamine dimesylate) suggested the drug may have a lower potential for abuse among drug abusers.

The study was a double-blind, placebo- and active-controlled, single-dose crossover pharmacodynamic and pharmacokinetic study to evaluate the safety, tolerability and abuse liability of intravenously administered NRP104 in healthy adult volunteers with histories of stimulant abuse.

NRP104 is the subject of a New Drug Application filed with the Food and Drug Administration Dec. 6, 2005 seeking approval for three therapeutic doses (30, 50 and 70 mg) of NRP104 for the treatment of attention-deficit/hyperactivity disorder in pediatric populations.

On a mole weight basis, the amphetamine free base content in NRP104 50 mg is equivalent to the amphetamine free base content of 20 mg of d-amphetamine sulphate, a schedule 2 stimulant, according to a news release.

Given intravenously, d-amphetamine sulfate 20 mg produced significant responses on the measures of amphetamine-like effects that peaked within 15 minutes of administration.

These included significant euphoric responses and amphetamine-like subjective effects, the release said.

Under the same conditions, NRP104 50 mg did not produce euphoria or amphetamine-like subjective effects, as evidenced by the lack of significant responses on these same scales.

The company said it believes that this indicates that lisdexamfetamine dimesylate 50 mg given intravenously is significantly less reinforcing than d-amphetamine 20 mg given intravenously.

Even though they contain equal amounts of d-amphetamine base, in the treatment enjoyment assessment questionnaire administered at the end of the study, eight out of nine (89%) of the study subjects stated that they would not take lisdexamfetamine dimesylate 50 mg again, while six out of nine (67%) of the study subjects stated that they would take 20 mg d-amphetamine again.

The company said these results indicate that NRP104 appeared to have little likelihood for abuse by the intravenous route.

New River Pharmaceuticals is a specialty pharmaceutical company located in Radford, Va.

© 2015 Prospect News.
All content on this website is protected by copyright law in the U.S. and elsewhere. For the use of the person downloading only.
Redistribution and copying are prohibited by law without written permission in advance from Prospect News.
Redistribution or copying includes e-mailing, printing multiple copies or any other form of reproduction.