Skinfold thickness for rivastigmine patch application in Alzheimer's disease.

ABSTRACT

RATIONALE Rivastigmine patches are used for patients with Alzheimer's disease (AD), but little is known about the serum concentration of rivastigmine and its metabolite or clinical adherence in relation to skinfold thickness after rivastigmine patch application. OBJECTIVES: The aim of this study was to examine the association between rivastigmine and NAP 226-90 serum concentration and skinfold thickness and to determine the appropriate skinfold thickness for the use of rivastigmine patch in patients with AD. METHODS: Patients with AD who continuously used rivastigmine patches (4.6 mg/24 h, 5 cm2) for more than 6 months were recruited. The serum concentrations of rivastigmine and NAP 226-90 were measured. Skinfold thickness was measured using a Lange Skinfold Caliper. RESULTS: In total, 91 patients with AD (40 men and 51 women) participated in this study on skinfold thickness measurement. Among them, 27 patients were examined for rivastigmine and NAP 226-90 serum concentrations, with mean concentrations of 1.0 ± 0.6 ng/mL and 3.6 ± 3.6 ng/mL, respectively. The skinfold thickness in the subscapular area was significantly negatively correlated with the NAP 226-90 serum concentration (Spearman's rank correlation coefficient = - 0.47, P = .01). In addition, patients with AD and a subscapular skinfold thickness of ≥25 mm exhibited a significantly high risk of decreased Mini-Mental Status Examination score and nonadherence to a rivastigmine patch (odds ratio 3.00; 95% confidence interval = 1.076-8.366, P = .03). CONCLUSIONS: Subscapular skinfold thickness was significantly negatively correlated with the NAP 226-90 serum concentration and may be considered an appropriate predictor of response and adherence to clinical application of a rivastigmine patch.