Characterising Hand Tremor in Adult Kidney Transplant Recipients: Its Impact on Daily Activities and Relationship With Tacrolimus Administration and Exposure

ABSTRACT Aim This study aimed to characterise hand tremor and examine its relationship with tacrolimus administration time and systemic exposure in adult kidney transplant recipients early post‐transplantation. Methods Quantitative and qualitative data on hand tremor were collected from patients receiving immediate‐release tacrolimus, approximately 1 month post‐transplantation. Smartphone accelerometry was used to objectively assess tremor pre‐ and 2 h post‐tacrolimus administration and values were compared using a Wilcoxon signed‐rank test. A Welch's analysis of variance (ANOVA) was used to determine if tacrolimus trough concentration ( C 0 ), 2 h post‐dose concentration ( C 2 ) and the ratio of C 2 / C 0 were significantly different between patients reporting no, mild or moderate/severe tremor. Results One hundred and seven patients enrolled in the study. Eighty percent of patients reported hand tremor, often during voluntary hand movement. Thirty‐eight percent said it interfered with daily activities, impeding their ability to perform basic daily tasks required for eating, drinking, accessing medicines and working. Hand tremor was not more severe at 2 h post‐tacrolimus intake. Tacrolimus exposure was not associated with patient‐reported tremor severity. Significantly greater amplitude and power in hand movement were detectable by smartphone accelerometry in patients reporting hand tremor. Conclusion Hand tremor is highly prevalent early post‐transplantation and has a major impact on patient functionality and quality of life. Further research is needed to develop novel tacrolimus exposure estimates that better correlate with tremor, and to identify improved ways to clinically assess, manage and mitigate the impact of hand tremor following transplantation. Smartphone accelerometry may be a useful tool in assessing tremor in future studies.