RESUMO
Background: Desmopressin is frequently used perioperatively in persons with nonsevere hemophilia A. However, increase in factor (F)VIII:C after desmopressin use is interindividually highly variable. Tachyphylaxis has only been reported in test setting for persons with hemophilia A, with a remaining response of approximately 70% after a second dose compared with that after a first dose. Objectives: To study tachyphylaxis of FVIII:C response after multiple administration(s) of desmopressin in perioperative persons with nonsevere hemophilia A. Methods: We studied FVIII:C levels after desmopressin before (day 0 [D0]) and on days 1 (D1) and 2 (D2) after surgery in 26 patients of the DAVID and Little DAVID studies. We studied tachyphylaxis by comparing the responses at D1 and D2 with that at D0. We also assessed the reproducibility of the D0 response in comparison to an earlier performed desmopressin test. Results: The median absolute FVIII:C increase was 0.50 IU/mL (0.35-0.74; n = 23) at D0, 0.21 IU/mL (0.14-0.28; n = 17) at D1, and 0.23 IU/mL (0.16-0.30; n = 11) at D2. The median percentage of FVIII increase after the second administration (D1) compared with the first (D0) was 42.9% (29.2%-52.5%; n = 17) and that of the third (D2) compared with the first (D0) was 36.4% (23.7%-46.9%; n = 11). The FVIII:C desmopressin response at D0 was comparable with the desmopressin test response in 74% of the patients. Conclusion: Tachyphylaxis in the surgical setting was considerably more pronounced than previously reported, with FVIII:C at D1 and D2 of 36% to 43% of the initial response. Our results may have important implications for monitoring repeated desmopressin treatment when used perioperatively.
RESUMO
Long-term adherence to prophylactic therapy is the key to successful prevention of bleeds in severe haemophilia. The present study aims to provide a systematic review of the literature on the determinants of adherence to prophylaxis in haemophilia. A literature search in the largest medical databases in Oct 2011 yielded 880 articles, which were reduced to 72 by further selection on title. Twenty-eight articles were excluded due to inclusion criteria. Full paper evaluation of 44 articles yielded five relevant articles that were critically appraised using the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) statement and items extracted from the critical appraisal criteria for cohort studies (Dutch Cochrane Centre). After critical appraisal, 2/5 studies were considered as the best evidence available. The results of these two studies were further used in the synthesis for description of the determinants of adherence. This concerned a total of 245 subjects in all age groups. Data were collected using questionnaires and interviews. Motivators for a high adherence were as follows: experience of symptoms, a positive belief of necessity of treatment and a good relationship with the health care provider. Important barriers were defined as: infrequent or absence of symptoms and increasing age. Two high-quality studies were identified. Reported determinants of adherence to prophylaxis were age, symptoms, beliefs, and the relation with the health care provider. This information may provide a first step towards a strategy to promote adherence in haemophilia, with an important focus on age-specific interventions and patient education.