Incidence of Induration Caused by Sustained Release Preparation Psychiatric Patients and its Related Factors

Abstract

In this study I investigated the intramuscular injection of a sustained release preparation psychiatric patients. My aim was to clarify the incidence of induration and its related factors in order to consider methods for prevention of induration. Induration was confirmed in 11.0% of all cases, 30.0% of the patients developed induration, and induration newly occurred in 10.0% of the patients during the investigation period. The size of the induration ranged from 2×2 cm to 5×7 cm, and its hardness ranged from +7.4 to +12.3 relative to the normal area. By 8 weeks after injection, the induration showed a reduction in both size and hardness. However, because nurses performed injection on the same side, the induration again increased in size. Observation of induration was difficult by thermography but possible using ultrasonography. The factors associated with induration were active degradation, use of haloperidol decanoate, and an insufficient needle implant depth. I thought that induration might be prevented if injection was made deeply into a muscle, and that the muscle at the injection site remained active.