Assessment of calcium and vitamin D medications adherence in patients with hypoparathyroidism after thyroidectomy

In this study, we found that patients with hypoparathyroidism had a problem with calcium medication compliance, and this problem increased with the duration of the disease. We also showed that patients are concerned about the possible side effects of drugs.

Introduction: In this study, we aimed to evaluate adherence to active vitamin D and calcium replacement in patients with post-surgical hypoparathyroidism.

Methods: To elucidate the medication adherence, we performed a questionnaire survey using the six-item "Medication adherence questionnaire"(MAQ). The first, second, and sixth questions reflect the motivation status of the patients whereas the third, fourth, and fifth questions reflect the knowledge about the medication that is received. The responses are scored and patients are classified regarding their motivation to and knowledge about the particular drug.

Results: Totally, 64 patients (male: 12/female: 52; mean age 48.6±11.6 years) who had post-operative hypoparathyroidism were included in our study. Median disease durance was 60 months (min-max: 12-295 months). We found that motivation score of calcium usage was significantly lower compared to vitamin D usage (p<0.001). The calcium motivation score was reversely correlated with disease duration (r= -0.256 and p=0.046). The most common worry about calcium usage was nephrotoxicity, and the most common worries about calcitriol treatment were kidney damage and polyuria. One-third of the patients were taking oral calcium and calcitriol less than the recommended dose.

Conclusion: One-third of patients lack motivation to use calcium whereas half of the patients experiences anxiety about drug-related side effects. This is a preliminary study showing that vital calcium and active vitamin D intake may be interrupted due to side effect anxiety.