PSYCHOLOGICAL RESPONSES TO THE NEEDLE-FREE MEDI-JECTOR(R) OR THE MULTIDOSE DISETRONIC(R) INJECTION PEN IN HUMAN GROWTH-HORMONE THERAPY

The aim of the study was to test the hypothesis that daily administrat ion of growth hormone using the Medi-Jector(R) Bi results in fewer adv erse psychological responses than needle injection with a multidose in jection pen. The Medi-Jector is a needle-free injection device that ca n deliver growth hormone subcutaneously through jet injection. The gro up studied consisted of 18 children aged 10 y or over who were partici pating in a study of the bioequivalence and bioequipotence of the admi nistration of growth hormone through jet injection or needle injection . Previously, all subjects had received growth hormone therapy with co mmercially available multidose injection pens. The study was designed as a prospective, randomized, two-period cross-over trial. A questionn aire was used to assess psychological responses such as non-compliance , opinion on ease of preparation, affective responses to administratio n and local side-effects, as well as overall preference. In addition, the subjects kept a diary during the study. The subjects found the Med i-Jector less offputting (p < 0.01), less painful with respect to both frequency (p < 0.04) and intensity (p < 0.01) and less unpleasant (p < 0.05) than a multidose injection pen with a 28G needle (p < 0.01). N o difference in compliance was detected. Most subjects preferred the M edi-Jector for future use (p < 0.05). The mean score on a 1-10 point s cale (10 is excellent) was 7.9 (SD 1.4) for the Medi-Jector and 6.8 (S D 2.3) for the multidose injection pen (p < 0.08). The prevalence of v isible bruises each day was higher (p < 0.01) with the Medi-Jector (2. 5, SD 2.1) than with the multidose injection pen (0.7, SD 1.1), but ch ildren showed indifferent affective responses to bruising. Thirteen ou t of 18 subjects decided to continue therapy with the Medi-Jector (p < 0.06). It is concluded that use of the Medi-Jector in growth hormone therapy tends to lead to fewer adverse psychological responses than a multidose injection pen with 28G needles.