RESUMO
Quantitative studies have highlighted differences in several drugs approved for use in Spain in the treatment of attention deficit hyperactivity disorder. No clear differences are observed, however, in the case of qualitative studies. The number of patients needed to be treated in order for one to reach complete remission (NNT) of methylphenidate (MTF) is from 2.2 to 5, and the effect size (ES) is 0.9. Atomoxetine has an NNT of 4 and an ES of 0.7. The advantages of immediate-release MTF (IR-MTF) over the extended-release version (ER-MTF) lie in its low cost, its flexibility and the better results obtained in quantitative studies. In contrast, ER-MTF offers a lower risk of abuse, needs to be taken fewer times with less need for third parties to control administration, and there is a lower risk of stigmatisation. Combination or changes of IR-MTF and ER-MTF and the combination of MTF with atomoxetine are sometimes necessary to adjust the weekday or weekend doses. Starting treatment with IR-MTF and then maintaining or changing to ER-MTF offers certain advantages as regards safety, dose adjustments and dosage. Atomoxetine is the best alternative if there is a background of adverse events with low or moderate doses of stimulants, or lack of response to high doses of stimulants. In cases of notable comorbid anxiety, both MTF and atomoxetine have the same level of indication. If there is a risk of substance abuse, both atomoxetine and ER-MTF are the preferred treatment. For the other indications, MTF is the preferred treatment.