Patient evaluation of a new injection pen for growth hormone treatment in children and adults.

The aim of this study was to evaluate patients' perception and acceptance of a new multi-dose injection device (Genotropin Pen) for recombinant growth hormone (GH) supplied in a two-chamber cartridge. The pen is combined with a very thin needle (B-D Microfine + (29 G) and meets future demands when dosing of GH will be changed from International Units (IU) to milligrams (mg). A total of 39 children receiving GH treatment (East Hospital, Gothenburg and St Bartholomew's Hospital, London), aged between 7 and 17 years, and 39 GH-treated adults (Sahlgrenska Hospital, Gothenburg and Karolinska Hospital, Stockholm), aged between 20 and 68 years, participated in the study. The daily dose ranged from 0.3 mg to 2.6 mg. The injections were given subcutaneously, once daily, and most of the patients used the thigh as an injection site. After a trial period of 2 weeks, injection technique, pain, fear of injection and convenience of the Genotropin Pen were compared with the experience with the prestudy device (Genotropin KabiPen 16, 16(8) or 36) by questionnaire. A total of 95% of the patients preferred the Genotropin Pen to the prestudy device for the following reasons: a greater certainty of correct dosing with the digital display; the possibility of correcting the set dose; the lock function of the injection button when injection is complete; more comfortable to hold due to the design and the plastic material; and reduced pain when injecting due to the thinner needles. Four patients (5%) preferred the prestudy device KabiPen as they considered this to be 'good enough'. Thus, the Genotropin Pen is a convenient injection device and most patients prefer it to the KabiPen.