Feasibility and acceptability of an intranasal diamorphine spray as an alternative to injectable diamorphine for maintenance treatment.

An intranasal (IN) diamorphine spray was investigated as a possible alternative to injectable diamorphine for maintenance treatment. Plasma morphine and 6-monoacetylmorphine (6MAM) concentrations and pharmacodynamic responses were measured for 4 h following intravenous (IV) and IN administration of 40 mg diamorphine in 4 patients prescribed injectable diamorphine. The two routes were primarily differentiated by the significantly greater speed and magnitude of peak plasma morphine and 6MAM concentrations for IV versus IN diamorphine. Beyond this initial peak, mean ratings suggested that withdrawal suppression and positive effects were at least as strong for IN compared to IV administration. All subjects gave favourable appraisals of the IN diamorphine spray, citing advantages including ease of use, the avoidance of needle hazards, and reduced stigma. IN administration may be an alternative or supplementary form of diamorphine maintenance and deserves serious further investigation.