Opioid-Related Disorders clinical trials

Buccal Versus Injectable Naloxone: a Phase I Healthy Volunteer Study

Naloxone is the standard treatment in response to cases of suspected opiate overdose. Buccal formulation of naloxone is a novel alternative to the licensed naloxone injection which, by removing the risk of accidental needle-stick, may be safer and easier to administer. Current UK policy allows the emergency administration of naloxone by any member of the general public (Strang, Kelleher, Best, Mayet, & Manning, 2006), and the preventative provision of naloxone to drug users and their family members ("take-home naloxone") is possible on a prescription basis. Thus, buccal naloxone may be particularly suitable for administration by family members who are providing interim overdose management care while awaiting the arrival of an ambulance. The aim of this study is to examine the bioavailability and dose proportionality of buccal naloxone compared with the licensed injection standards (intravenous, intramuscular). The investigators hypothesise that buccal naloxone is not inferior to the injection reference in absorption kinetics, i.e. time elapsed till peak concentration (Tmax; primary outcome), peak plasma concentration (Cmax), overall absorption (AUC), bioavailability (F%) and, duration of action (mean terminal half-life; T1/2). The investigators propose a pharmacokinetic pilot investigation with within-subjects (crossover) design, comparing two doses (0.8 mg; 1.6 mg) of buccal naloxone hydrochloride solution to the licensed intramuscular (IM; 0.8 mg) and intravenous (IV; 0.8 mg) routes of injection. The investigators will invite four healthy (i.e., non-opioid using) male volunteers (n=4, not powered), each of whom will attend four experimental sessions at counterbalanced sequence. Each volunteer will receive naloxone hydrochloride doses of 0.8 mg IM, 0.8 mg IV, 0.8 mg buccal, and 1.6 mg buccal, with only one dose administered per session. Blood concentrations will be measured at selected times during each session to establish speed of naloxone absorption, time to peak concentration, estimated half-life, and overall bioavailability. This dose-ranging pilot will inform future work by providing preliminary data on buccal naloxone absorption into the bloodstream and by establishing feasibility of the buccal route for naloxone delivery.