Dried Blood Spot Analysis for Therapeutic Drug Monitoring of Antipsychotics: Drawbacks of Its Clinical Application.

BACKGROUND: Dried blood spot (DBS) sampling offers a minimally invasive sampling method for therapeutic drug monitoring of antipsychotics. To facilitate implementation in clinical practice, the aim of this study was to perform a clinical validation study of a DBS method for quantification of risperidone, aripiprazole, pipamperone, and their major metabolites 9-OH risperidone and dehydro-aripiprazole in a real-life, clinical setting. METHODS: Paired DBS and venous plasma samples were analyzed (n = 35 for risperidone, n = 21 for aripiprazole, n = 21 for pipamperone). Estimated plasma concentrations were calculated from DBS concentrations based on hematocrit and/or Deming regression formulas. Deming regression and Bland-Altman analyses were used to determine the agreement between the calculated and measured plasma concentrations. For Bland-Altman analysis, the following acceptance limit was used: for a minimum of 67% of the samples, the difference of the 2 measurements should be within 20% of their mean. RESULTS: The median venous plasma levels were 0.9 mcg/L for risperidone, 14.8 mcg/L for 9-OH risperidone, 135.4 mcg/L for aripiprazole, 54.9 mcg/L for dehydro-aripiprazole, and 56.4 mcg/L for pipamperone. All antipsychotics required different correction formulas of DBS concentrations for best agreement. Subsequently, no constant or proportional bias was observed using Deming regression analysis. With Bland-Altman analyses, for risperidone, 45% of the samples were within the 20% limits; for 9-OH risperidone, 36%; for aripiprazole, 45%; for dehydro-aripiprazole, 35%; and for pipamperone, 43%. CONCLUSIONS: The DBS method to quantify risperidone, aripiprazole, pipamperone, and their major metabolites did not meet the acceptance criteria in the Bland-Altman analyses. Therefore, this DBS method was not clinically valid. This study shows the importance of a clinical validation study with use of Bland-Altman plots before clinical implementation.

[Sexuality and contraception in young people with mild intellectual disability; a qualitative study on the basis of 28 interviews]. / Seksualiteit en anticonceptie bij licht verstandelijk beperkte jongeren; een kwalitatief onderzoek op basis van 28 interviews.

OBJECTIVE: To investigate how doctors can improve the advice and education about sexuality and contraception given to young people with mild intellectual disability (IQ :50-70). DESIGN: Semi-structured interviews. METHOD: Young people attending special needs secondary schools (IQ: 50-70) were interviewed. Pupils with a known history of sexual abuse were excluded. RESULTS: A total of 17 of the 57 potential candidates were excluded. Of the remaining 40 pupils, 28 agreed to take part (13 male; age range: 15-18 years, average IQ: 58). Of the 28 participants, 19 had been in a relationship, 5 had experience with sexual intercourse and 11 used contraception. Just as in other studies, the participants seemed to have less knowledge, and less experience than young people of their age without a disability, but did show interest. They were at increased risk because of inappropriate use of contraception and had limited social resilience. Only knowledge about the pill and condoms was fair to good. Interest and knowledge seemed greater in those young people in a relationship. Poor verbal skills hampered their understanding of the questions asked and of the information offered, and limited their ability to express feelings and opinions. Those young people in a relationship wanted to choose their own form of contraception. CONCLUSION: In this group of vulnerable young people, provision of sexual education by the doctor at the right moment using simple language and repetition, can contribute to the timely and safe use of contraceptives.Conflict of interest and financial support: none declared.